I'm currently on holiday in the alps , and have been having problems with an over-heating fuel pump . After a few hours driving it just cuts out
without warning , and wont restart .
Pulling the return line at the fuel rail revealed no fuel , just high pressure vapour - every time its happened I have had to remove the return at the
tank sender , and bleed the system . I did remove the pump first time , and it was too hot to touch , so I am currently sitting on a campsite waiting
for a fuel pump to be delivered........
Which has got me thinking of some kind of cooler in the return line - I work on modern diesel vans all day , and they all have them .
The fuel is getting pumped to a hot engine bay (the fuel rails are near as hot as the engine !) picking up heat , the return into the tank is right
next to the pump so almost a direct return path , all of which will be building heat .
I'm thinking something like a small oil cooler in the return , after the regulator , right out in front of the rad - good idea or not ?
Some manufactures have gone return less fuel pump. But I don't know of any after market ecu to control the driver module.
How about a zig-zag of copper pipe to act as a simple cooler? The mx5 has a pipe like that, I think (but not checked as nothing ever seems to go
wrong) that it is for power steering fluid? But a similar one for fuel should help, and be very simple.
Another point, the old Triumph PI systems are often modified by having a coil of the return pipe around the fuel pump to cool the pump. I am guessing
there the petrol tank will soak the heat up.
Don't put it in front of the rad, you'll have fuel everywhere in a shunt - not good!
I think its a good idea, you could mount a small cooler near to the diff, like some jap cars do to cool the diff oil.
Heat is the enemy, however the ethanol content fuel creates a much lower boiling point use high octane as this tends to have a lower content of
ethanol.
France is particularly bad as they run 10% ethanol, in the UK you can look E5 = 5% E10 = 10% so go for '98 Sans Plomb' and try and work out
from the markings if you have a choice and go for the lowest ethanol content.
At an autosolo last year some mini's had this problem, the glass fuel bowl on the bulkhead was literally boiling fuel, the cars that suffered had
filled up on cheap supermarket fuel, I suspect your fuel pump is causing the fuel to boil so is then unable to cool itself.
HTH
Regards Mark
[Edited on 19/7/14 by mark chandler]
Hi Mark
Good advice, and I didn't know that. I tend to run Shell Optimax, and when I'm feeling generous, Aldon Octane booster.
There fuel coolers available on JIC fittings, and the advice I was given was "see how you do before you fit one". It sounds like Claire has
hit that point.
quote:
Originally posted by mark chandler
Heat is the enemy, however the ethanol content fuel creates a much lower boiling point use high octane as this tends to have a lower content of ethanol.
France is particularly bad as they run 10% ethanol, in the UK you can look E5 = 5% E10 = 10% so go for '98 Sans Plomb' and try and work out from the markings if you have a choice and go for the lowest ethanol content.
At an autosolo last year some mini's had this problem, the glass fuel bowl on the bulkhead was literally boiling fuel, the cars that suffered had filled up on cheap supermarket fuel, I suspect your fuel pump is causing the fuel to boil so is then unable to cool itself.
HTH
Regards Mark
[Edited on 19/7/14 by mark chandler]
Could also be caused by the pump cavitating due to the line to the pump being too small / not having enough static head or a restriction in the supply
line like a pre filter.
If the fuel gets warm enough any draw/suction from the pump lowers the pressure and just instantly boils the fluid, this is also why many systems run
a slightly pressurised fuel tank.
quote:
Originally posted by madteg
I think its a good idea, you could mount a small cooler near to the diff, like some jap cars do to cool the diff oil.
Another simple solution that I learned in really hot climates and having gone through an expensive fuel pump is to keep your fuel tank as full as possible by filling up whenever the opportunity presents itself - this makes for a bigger heat sink for the returned fuel giving it more time to cool down before it is pumped back through the system and re-heated.
Copper coil heat exchangers are used in home brewing, or could you fit an in tank pump?
I've never seen or know about a factory standard car having fuel overheating problems or needing a pump replacement unless high mileage.
So, assuming the car Claire is driving now is not standard the issue will be one of two things, poor quality pump or incorrectly installed.
Pump should be under the tank (head of fuel) with no pre filter, with large feed pipe (normally 12mm bore)
Most Efi pumps will not suck fuel, if a restriction is present on the inlet it will cause the pump to run hot. Also, running the pump in lockout
(return blocked) will cause it to run hot.
More than 30 seconds of running an Efi pump dry, or in lockout will damage it.
Do you return the exes fuel to the tank or swirl pot? I have heard of this happening when the return is to the swirl pot. Does any one have a good article on fuel system design?
quote:
Originally posted by ceebmoj
Do you return the exes fuel to the tank or swirl pot? I have heard of this happening when the return is to the swirl pot. Does any one have a good article on fuel system design? [/quot
If you have seen this happening with a swirl pot then the system probably was on the brink of failure any way - the reason i say this is we have seen a couple of cars on the dyno that started off with very quite pumps and after a few hours the pumps have got slightly noisy (not causing a problem, but you could hear the pump) On investigation we have concluded the fuel system wasn't quite right and after minor alterations was corrected the problem.
Any liquid is harder to pump when its hot, some worse than others, water is a bad one and i suspect so is petrol.
The liquid within a pump can get agitated, causing small bubbles to form, these bubbles hold the liquid away from the pump impellers making the pump less efficient.
The noise you can hear from a pump is the noise made by the fuel / bubbles and the pump impellers hitting each other, the loss of efficiency reduces the pumps ability to move the fuel and the cavitation gets worse.
As most pumps consume around 40watts of electrical power, and rely on the fuel flow for cooling, to add to that normally the 40watts of energy is used to do the work of pumping - if the pumps efficiency is reduced by cavitation the energy goes to heat. This heats the fuel and the actual pump - making it harder to pump - eventually the whole thing spirals out of control and the pump fails completely or just stopping working until its allowed to cool down.
The issue maybe resolved by a fuel cooler, but your barking up the wrong tree, the real problem is poor system design or just a crap pump.
ceebmoj - 19/7/14 at 12:04 PMquote:
Originally posted by BaileyPerformance
quote:
Originally posted by ceebmoj
Do you return the exes fuel to the tank or swirl pot? I have heard of this happening when the return is to the swirl pot. Does any one have a good article on fuel system design?
If you have seen this happening with a swirl pot then the system probably was on the brink of failure any way - the reason i say this is we have seen a couple of cars on the dyno that started off with very quite pumps and after a few hours the pumps have got slightly noisy (not causing a problem, but you could hear the pump) On investigation we have concluded the fuel system wasn't quite right and after minor alterations was corrected the problem.
Any liquid is harder to pump when its hot, some worse than others, water is a bad one and i suspect so is petrol.
The liquid within a pump can get agitated, causing small bubbles to form, these bubbles hold the liquid away from the pump impellers making the pump less efficient.
The noise you can hear from a pump is the noise made by the fuel / bubbles and the pump impellers hitting each other, the loss of efficiency reduces the pumps ability to move the fuel and the cavitation gets worse.
As most pumps consume around 40watts of electrical power, and rely on the fuel flow for cooling, to add to that normally the 40watts of energy is used to do the work of pumping - if the pumps efficiency is reduced by cavitation the energy goes to heat. This heats the fuel and the actual pump - making it harder to pump - eventually the whole thing spirals out of control and the pump fails completely or just stopping working until its allowed to cool down.
The issue maybe resolved by a fuel cooler, but your barking up the wrong tree, the real problem is poor system design or just a crap pump.
Do you have an example of well designed system or a good reference article?
BaileyPerformance - 19/7/14 at 12:25 PMNo sorry I don't have any docs or written info.
We've designed several system but it all from experience.
Ivan - 19/7/14 at 03:04 PMquote:
Originally posted by BaileyPerformance
I've never seen or know about a factory standard car having fuel overheating problems or needing a pump replacement unless high mileage.
So, assuming the car Claire is driving now is not standard the issue will be one of two things, poor quality pump or incorrectly installed.
Pump should be under the tank (head of fuel) with no pre filter, with large feed pipe (normally 12mm bore)
Most Efi pumps will not suck fuel, if a restriction is present on the inlet it will cause the pump to run hot. Also, running the pump in lockout (return blocked) will cause it to run hot.
More than 30 seconds of running an Efi pump dry, or in lockout will damage it.
Although what you say re installation is correct this is a regular occurrence in South Africa - I know from experience with Volvo's - mine was a T4 and happened outside Beaufort West - but other manufacturers also experienced it. The tow company immediately identified the problem and told me that it was a common problem with European and Scandinavian cars and that, if I kept tank as full as possible, I would have no problems on my remaining 2500km trip to Jo'burg and back to Cape - they were right. Volvo even carried half the cost of the pump as a tacit admission of a problem although they denied it..
The initial answer is to stop until fuel cools -you have no choice as car won't run anywayand then to keep tank full. Of course the pump will have to be replaced ASAP as problem just gets worse because pump has lost efficiency and heats the fuel up faster - the full tank thing is to get you home or to the agents.
clairetoo - 19/7/14 at 04:48 PMSome very interesting information there guys - it does fit my theory that heat buildup is an almost runaway thing , I cant see it being a poorly designed system as its an Mx5 , only with a walbro pump (or should that be wallmart......) , running a V6 with a decent aftermarket adjustable fuel pressure regulator .
I am currently wasting a few days of my holiday waiting for a second-hand stock pump to be delivered here as I've come to the conclusion that the pump is now knackered......tried to go for a gentle drive today , starting with a full tank , and managed a whole 120 kilometers before it quit.......still with over 3/4 of a tank .
Before it died , it had been running weak for a while , so probably lost fuel pressure , and the temp was in the low 30's .
I've run a similar setup in my Fury without problem , so the main culprit has to be a dodgy pump . It will be getting a cooler of some kind when I get back - spraying hot fuel into the inlet flow cant be helping power.....
BaileyPerformance - 19/7/14 at 09:00 PMquote:
Originally posted by clairetoo
Some very interesting information there guys - it does fit my theory that heat buildup is an almost runaway thing , I cant see it being a poorly designed system as its an Mx5 , only with a walbro pump (or should that be wallmart......) , running a V6 with a decent aftermarket adjustable fuel pressure regulator .
I am currently wasting a few days of my holiday waiting for a second-hand stock pump to be delivered here as I've come to the conclusion that the pump is now knackered......tried to go for a gentle drive today , starting with a full tank , and managed a whole 120 kilometers before it quit.......still with over 3/4 of a tank .
Before it died , it had been running weak for a while , so probably lost fuel pressure , and the temp was in the low 30's .
I've run a similar setup in my Fury without problem , so the main culprit has to be a dodgy pump . It will be getting a cooler of some kind when I get back - spraying hot fuel into the inlet flow cant be helping power.....
It's nothing to do with fuel temp, if it is your car is an exceptional case?, which is unlikey.
The conversions you are doing are nothing clever, your car is not out if the ordinary, so why does it need an odd ball fuel system? The problem is your installation is wrong or your pump is crap or most likely both.
There are millions of cars on the road with basic fuel systems that run fine, your not making big power per litre or running 9000rpm. Stop looking for the complicated solution :-)
clairetoo - 20/7/14 at 08:17 AMJeez you sure a proper keyboard warrier Bailey.........if you ever fall off that high horse of yours you better have a parachute handy.......
I've already said its pretty much a stock Mx5 system , exept for a walbro pump (which I have already said I think is duff) and an adjustable FPR .
Are you trying to tell me Mazda screwed up when they designed the stock system ? And that every manufacture of diesel vans is running an `oddball system' because they dont know how to design a fuel system ?
You have been on my case ever since I said on here that I wasnt impressed with the mapping you did on a friends car - nothing has changed , it was utter shite......basically a 2D map in a 3D system......all straight lines from zero revs to max revs........on both fuel and ignition .
I have never seen maps like them , this was a number of years ago , and I still havnt yet . I figure you had tuned for max power , and sod the rest as long as it works...............
So , lets agree to disagree on all matters to do with tuning - and if you have nothing usefull to add , please stop spamming my threads .
BaileyPerformance - 20/7/14 at 09:40 AMquote:
Originally posted by clairetoo
Jeez you sure a proper keyboard warrier Bailey.........if you ever fall off that high horse of yours you better have a parachute handy.......
I've already said its pretty much a stock Mx5 system , exept for a walbro pump (which I have already said I think is duff) and an adjustable FPR .
Are you trying to tell me Mazda screwed up when they designed the stock system ? And that every manufacture of diesel vans is running an `oddball system' because they dont know how to design a fuel system ?
You have been on my case ever since I said on here that I wasnt impressed with the mapping you did on a friends car - nothing has changed , it was utter shite......basically a 2D map in a 3D system......all straight lines from zero revs to max revs........on both fuel and ignition .
I have never seen maps like them , this was a number of years ago , and I still havnt yet . I figure you had tuned for max power , and sod the rest as long as it works...............
So , lets agree to disagree on all matters to do with tuning - and if you have nothing usefull to add , please stop spamming my threads .
Go and have a look on mx5nuts and see the number of mx5s we have mapped, most with standard fuel systems, the stock pump is fine to 250bhp.
If you have changed your pump and maybe raised the fuel pressure then its no longer a stock fuel system.
If the new pump has a lot more flow than the stock pump then that can cause a problem.
Nissan 200/300sx have a fuel pump controller (still with a return), skylines have a fuel pump resistor that is shorted out(via Ecu) when under boost.
I guess the reason for this the pumps are sized to supply the fuel for full throttle / full boost and so are pumping hard for no reason at light throttle.
Standard mx5s don't have any fuel heating issues - I know this as I have had them on the dyno all day with varying levels of fuel in the tank. If heating was an issue it would have happened on the dyno as there is little air flow over fuel lines and the tank.
I think I have an old megatune backup of your mates car, If I can find it I will take a look at what i did, but as I said when you posted your comments about bad mapping
if the customer is not happy I will refund or map again. I suggest it's more likely it you who has no idea what you looking at.
At the time your where out of order posting what you did without contacting me first - I probably lost some business do to it.
davidimurray - 20/7/14 at 09:42 AMAny fuel filters that could be partially clogged?
BaileyPerformance - 20/7/14 at 09:50 AMquote:
Originally posted by Ivan
Although what you say re installation is correct this is a regular occurrence in South Africa - I know from experience with Volvo's - mine was a T4 and happened outside Beaufort West - but other manufacturers also experienced it. The tow company immediately identified the problem and told me that it was a common problem with European and Scandinavian cars and that, if I kept tank as full as possible, I would have no problems on my remaining 2500km trip to Jo'burg and back to Cape - they were right. Volvo even carried half the cost of the pump as a tacit admission of a problem although they denied it..
The initial answer is to stop until fuel cools -you have no choice as car won't run anyway
That's interesting, was it worse during hot weather?
I did have an Autograss car once that had a noisy pump, on the dyno the tank did get warm to touch (small one gallon ally tank) it was fitted with a Bosch 044 pump, the engine (Honda vtec) made 235bhp so the pump was well over rated.
Just out of interest we decided to fit a pump resistor (0.47ohm) this dropped the pump supply from 14v to 12v with engine running. The pump went quite.
pewe - 20/7/14 at 10:21 AMOK I'll say what others on here are no doubt thinking - Clairetoo & Bailey you've done your handbagging bit in equal amounts so why not kiss and make up?
As another constructive comment have you checked all the connections are tight and pipework not perished or split?
Years ago whilst perched on top of a mountain in the Black Forest our 760 Volvo refused to pump anything more than half a tank. Turned out the in-tank lift pump had a split in the rubber connector pipe but underneath/behind the pipe clip which secured it.
Once the fuel level dropped it started to suck air rather than fuel.
Given I was reluctant to pay local garage charges I telephoned a colleague back in the UK and had them go to the local Volvo agent and buy a replacement pipe (a few quids worth of nitrile IIRC).
At 1500hrs on a Friday afternoon they posted it SwiftAir from the local post office to the campsite.
We were walking down to the local village on Sunday morning when a helicopter clattered up the valley.
Jokingly I said to the better half "that will be our pipe arriving".
Arriving back at the site later we were handed the SwiftAir package.
Efficient these Germans, Deutsche Post had only sent a helicopter up with it!
Hope you get sorted Claire.
Cheers, Pewe10
clairetoo - 20/7/14 at 10:37 AMquote:
Originally posted by pewe
OK I'll say what others on here are no doubt thinking - Clairetoo & Bailey you've done your handbagging bit in equal amounts so why not kiss and make up?
As another constructive comment have you checked all the connections are tight and pipework not perished or split?
Years ago whilst perched on top of a mountain in the Black Forest our 760 Volvo refused to pump anything more than half a tank. Turned out the in-tank lift pump had a split in the rubber connector pipe but underneath/behind the pipe clip which secured it.
Once the fuel level dropped it started to suck air rather than fuel.
Given I was reluctant to pay local garage charges I telephoned a colleague back in the UK and had them go to the local Volvo agent and buy a replacement pipe (a few quids worth of nitrile IIRC).
At 1500hrs on a Friday afternoon they posted it SwiftAir from the local post office to the campsite.
We were walking down to the local village on Sunday morning when a helicopter clattered up the valley.
Jokingly I said to the better half "that will be our pipe arriving".
Arriving back at the site later we were handed the SwiftAir package.
Efficient these Germans, Deutsche Post had only sent a helicopter up with it!
Hope you get sorted Claire.
Cheers, Pewe10
Thats pretty cool - I'm waiting on the Italian postal service to deliver me a replacement stock pump (supposed to be here tomorrow morning.....)
Cant see them sending a helicopter though........maybe a man on a Vespa
I did wonder if the stock pump would be man enough , but the walbro came up at a good price........I've since found that the Mx6 (where the V6 came from) has the same part number for the pump as the Mx5 .
Edit to add - its all metal inside the tank , so no hose to perish , and the `o' ring is good , also checked all the electrical connections .
[Edited on 20/7/14 by clairetoo]
pewe - 20/7/14 at 10:53 AMWhereabouts in Italy are you?
If South West near France try the Cenis Pass above Susa, West of Turin - great road.
Also the road up to Sestriere from Pinerola is worth the detour.
Also from Briancon South East the Col d'Izoard which they've just done on the Tour de France yesterday looks epic!
Making me quite envious but we're there in Sept for GP Nuvolari so our time will come.
Enjoy.
Cheers, Pewe10
[Edited on 20/7/14 by pewe]
clairetoo - 20/7/14 at 12:36 PMI'm currently near Cavalese (between Bolzano and Trento) - there are literally dozens of small passes around here - everything from fast and scary , to narrow and very scary ! I went over Passo Duran the other day - most of it is no more than single lane , lots of blind humps and tight corners.........
The Stelvio has to be the best so far - dozens of second gear hairpins , good job I fitted a big brake conversion before I went.....still managed to turn all four discs blue though !
And one thing has pleased me - I removed the power steering when I did the engine swap - and havnt missed it at all .
Happy days !
Ivan - 20/7/14 at 05:41 PMquote:
Originally posted by BaileyPerformance
That's interesting, was it worse during hot weather?
I did have an Autograss car once that had a noisy pump, on the dyno the tank did get warm to touch (small one gallon ally tank) it was fitted with a Bosch 044 pump, the engine (Honda vtec) made 235bhp so the pump was well over rated.
Just out of interest we decided to fit a pump resistor (0.47ohm) this dropped the pump supply from 14v to 12v with engine running. The pump went quite.
Yes it largely occurs in hot weather >30C, of course in those conditions the tar roads become very hot and radiate heat up to the tank and car under-body possibly making things worse.
clairetoo - 20/7/14 at 07:15 PMquote:
Originally posted by Ivan
quote:
Originally posted by BaileyPerformance
That's interesting, was it worse during hot weather?
I did have an Autograss car once that had a noisy pump, on the dyno the tank did get warm to touch (small one gallon ally tank) it was fitted with a Bosch 044 pump, the engine (Honda vtec) made 235bhp so the pump was well over rated.
Just out of interest we decided to fit a pump resistor (0.47ohm) this dropped the pump supply from 14v to 12v with engine running. The pump went quite.
Yes it largely occurs in hot weather >30C, of course in those conditions the tar roads become very hot and radiate heat up to the tank and car under-body possibly making things worse.
That was largly my point - in very hot conditions , and with sustained driving , everything gets hot.........just sitting in the car stationary was almost unbearable , and I think there is a major heat buildup (something you could never replicate on a simple rolling road - even major car manufactures take there new cars out to the dessert to test for this sort of thing)
So.......back to the whole point of the thread - some kind of fuel cooler - good or bad idea ? It cant do any harm , surely ?
Ivan - 21/7/14 at 07:35 AMI agree Claire - fuel cooler is a good thing - even on the hot days it will pull some excess heat out of the fuel if it's in the air stream, but put it as close to the tank as possible to stop radiant heat from the road getting back into the fuel in those very hot conditions. Also make sure its safe from strikes from tyre thrown stones.
Another choice is welding, or brazing, or soldering, some long fins onto the return line. Maybe use a copper line with fins soldered on.
[Edited on 21/7/14 by Ivan]
BaileyPerformance - 21/7/14 at 07:46 AMI think there are spare analogue inputs on megasquirt that can be configured as temperature inputs, would be interesting to log the fuel temp of the return line while driving?
coyoteboy - 21/7/14 at 12:18 PMTBH I'm surprised most normal cars don't risk that with high temp use - ethanol boils at ~late 70sC, petrol at 95ish C (when not under pressure) - I reckon it's pretty close in normal conditions with the position and lack of cooling available to more fuel rails.
clairetoo - 21/7/14 at 02:58 PMI'm also thinking another cause of my problem may be the V6 - Mx5's don't have an exhaust on the righthand side of the car where the fuel lines run........
Plenty of time to think today.....been raining non-stop , and the promised fuel pump didn't turn up.......
BaileyPerformance - 21/7/14 at 03:18 PMquote:
Originally posted by coyoteboy
TBH I'm surprised most normal cars don't risk that with high temp use - ethanol boils at ~late 70sC, petrol at 95ish C (when not under pressure) - I reckon it's pretty close in normal conditions with the position and lack of cooling available to more fuel rails.
If the fuel system is incorrectly sized, or a poor quality pump is used, its more likely to be susceptible to high fuel temps causing an issue - fuel is harder to pump when warm - I cant see fuel ever boiling unless the pump starts to cavitate which should cause the pump to get very hot then maybe the fuel within the pump could boil.
I have seen a pump burn out (so hot you can't touch it) when it's in lockout due to high fuel pressure - as the fuel in recirc so no cooing medium for the pump.
It would be interesting to actually monitor the fuel temps, maybe the return from the engine and the input to the pump.
Unless its knakered, you wouldn't expect the actual pump to add much heat to the fuel, assuming 50% efficiency no more than 20watts.
So, I suppose that leaves the engine - hard to say what that would add to the fuel , but the more and/or longer the fuel rails then the more heat that will be added?
I would think the fuel heating would be worse in traffic, not on a long run as airflow would keep fuel rails, fuel lines and the tank cool?
blakep82 - 21/7/14 at 03:34 PMquote:
Originally posted by clairetoo
I'm also thinking another cause of my problem may be the V6 - Mx5's don't have an exhaust on the righthand side of the car where the fuel lines run........
Plenty of time to think today.....been raining non-stop , and the promised fuel pump didn't turn up.......
So is the heat problem coming from the exhaust? Can you run the fuel line through some sort of insulation, heat reflecting sleeve etc?
Electric radiator fan blowing at the fuel tank? I would have thought the circulating fuel through the tank would be enough to keep it cool enough, but cant say its something I've ever thought much about.
On my pick up, the exhaust runs through the tunnel, as does the fuel line, the copper pipe is inside a plastic water pipe, to protect from the prop if it ever fails, and will get a heat shield too
BaileyPerformance - 21/7/14 at 05:13 PMquote:
Originally posted by clairetoo
I'm also thinking another cause of my problem may be the V6 - Mx5's don't have an exhaust on the righthand side of the car where the fuel lines run........
Plenty of time to think today.....been raining non-stop , and the promised fuel pump didn't turn up.......
Probably a silly question but could locate a breakers yard in the area?
I'm sure if you could locate a stock mx5 pump you'll be fine on the fuel demand and probably be fine on the fuel heating issue.
I'm 99% sure mx5 pumps are same as ford focus mk1, just different power connector (loads of those in scrap yards all over world)
BaileyPerformance - 21/7/14 at 05:16 PMWhen you change pump, the fuel pressure may well go up, as you may have set it with a knackerec pump from day one - worth checking it.
clairetoo - 21/7/14 at 05:30 PMThe replacement pump is now fitted and tested.....had to turn fuel Presque up slightly , and remove the pre filter as the whole thing (sender bracket and pump) were slightly different to mine .
I'll be plugging the laptop in on the drive home , to be sure of having it running right (the short test drive did show altered AFR's at cruise .
I'd advise all of you to check the temp of your fuel tank after a long run - first time I noticed this heat buildup was on an old transit that had been driven over 100 miles and straight into the workshop for fitting - the tank was as warm as a radiator......
alfablack - 21/7/14 at 09:38 PMthe lowest you would get a roatary in tank pump to pull is 12 watts or 1 amp upwards the rotary pumps are designed to operate between -30 to +150'f and use the fuel to centralize and cool the pump. it would not take much losses to generate extra heat to compensate for the loss in flow.
and if you are going to set the fuel pressure do it early in the morning before temperatures rise to much and run it on the lower side of suggested pressure as a map should correct the rest when set correctly