more crossflow tuning woessnippy - 13/4/14 at 09:05 PM
I am using this set up:-
1600 Crossflow with standard cam
Weber 32DGR carb
Accuspark distributor with electronic ignition
I`ve got it ticking over nicely around 900 rpm and it sounds very sweet. The problem I have is when I blip the throttle, it just dies, coughs and
splutters for a second or so. It sounds like it`s being starved because it sounds like it`s sucking air when I blip the throttle. If I raise the revs
slowly it will happily increase but isn`t sweet like at idle.
I`ve got the mixture screw wound out 2 1/2 turns from it`s full in position. My crank pulley didn`t have any marks to set up the timing so I best
guessed but can`t be far out because it ticks over lovely. It also starts straight away when cold and when hot.
So, is it timing issues or fuel starvation?
Does anyone know where the timing mark on the pulley should be relative to the woodruff key slot?
ReMan - 13/4/14 at 09:24 PM
I agree timing can't be far out, but nothing wrong with giving it a nudge either way and see if it helps.
Sounds more like fuel, through
Sucky noise can be normal.
Does this have an accelerator pump on the carb?
Has it ever ran correct on these jets?
Could it possibly be cam timing?
snippy - 13/4/14 at 09:29 PM
There is an accelerator pump yes and it does move when the throttle is blipped, you can see the `arm` moving. The carb was supplied brand new 20 years
ago together with the newly reconditioned engine. So, it did run back then (1994). Although it`s not run and been laid up for 20 years it`s all in
great condition. I`ve stripped the carb and all the jets are clear.
mark chandler - 13/4/14 at 10:11 PM
Engine off, when you pump the throttle you should see the accelerator pump arm move and a squirt of fuel exiting the nozzles, no fuel could be a
blockage or damaged diaphragm.
Laid up for 20 years?? Chances are fuel lines in the carb have fured up partially blocking fuel flow......Try another carb!
snippy - 14/4/14 at 08:20 PM
Mark, yes when engine off and throttle opened the accelerator pump arm is moving.
snippy - 14/4/14 at 08:24 PM
Fat gadget, the car hasn't run for 20yrs. During my restoration I have fully stripped and rebuilt the engine and carb to check internals. Both
were new items just before the car was laid up by previous owner. I've stripped carb again this evening to check all jets and everything is
clear.
snippy - 15/4/14 at 05:59 PM
Ok so I've measured where my timing mark is on the pulley in conjunction with the woodruff key slot in the centre of the pulley. The mark is
about 46 degrees past the slot. Can anyone confirm this is about right by measuring another Crossflow pulley? Please!
Smoking Frog - 15/4/14 at 06:20 PM
Set the timing before moving on to other things. If no marks, find TDC and work back from there.
snippy - 15/4/14 at 06:25 PM
I've done that, having found TDC you always get a 'Dead' area where the pulley will move without TDC moving. I've marked this dead
area to create my pulley mark.
Smoking Frog - 15/4/14 at 06:38 PM
quote:
I've done that, having found TDC you always get a 'Dead' area where the pulley will move without TDC moving. I've marked this dead
area to create my pulley mark
quote:Originally posted by snippy
There is an accelerator pump yes and it does move when the throttle is blipped, you can see the `arm` moving. The carb was supplied brand new 20 years
ago together with the newly reconditioned engine. So, it did run back then (1994). Although it`s not run and been laid up for 20 years it`s all in
great condition. I`ve stripped the carb and all the jets are clear.
You need to check the accelerator pump is actually squirting.
threadbare wallet - 15/4/14 at 06:53 PM
Have you got the acuspark plugs and leads? They are junk! They caused no end of problems with a simliar set up on my xflow,replaced them with ngk
plugs a copper leads and it ran and ticked over so much better and could rev out with out stuttering. Maybe worth a check.
snippy - 15/4/14 at 07:43 PM
The accelerator pump is squirting yes
snippy - 15/4/14 at 07:46 PM
I'm using a complete Accuspark set up - coil, dizzy, HT leads, plugs. I hope it's not their HT leads that's the issue. I've used
some spark testers whilst the engine is running and they do show good sparks. Hmm ????
threadbare wallet - 15/4/14 at 08:31 PM
If you have the splitfire type multi pronged electrode plugs sling them in the bin at least they really are rubbish,i did a test in a rig with normall
plugs and was amazed the thing was running at all! They were barely sparking on one pos two of the electrodes and they were so weak as to be hard to
see where as when i put standard ngk(very cheap of amazon) on with the same gap etc got a big fat spark that had direction! Then i changed the
leads....which had a actual staple shoved in the end to transmit the power to the cap and sorted all my ignition problems! The dizzy end seems ok but
will be changing that as soon as pos as well(it all came with the car) as dont really trust the quality after seeing the rest of it.
At least change the plugs they were about £6 from amazon or most motor stores.
chris_smith - 15/4/14 at 08:36 PM
going to throw a curve ball in here, as I had a problem with a 1300 xflow few years back, couldnt find the solution, changed pretty much everything I
could, then to find I had set the valve clearances when cold but not when hot, caused me no end of problems.
You're right re setting valve clearances on a hot engine for the 1300. The 1600 engine needs to be cold to adjust them according to Mr Haynes.
Good idea though thanks.
Just swapped Accuspark HT leads for some old HT leads I have but problem remains. I will try some different spark plugs and see if that makes a
difference.
Oldaker - 18/4/14 at 08:09 PM
Wind the mixture screw in a bit. Mine did this and I found weakening the mixture fixed it. On my engine. 2 1/2 turns out was too much
alfas - 21/4/14 at 06:57 AM
if valve celarance setting does not bring any result i would check the jetting of the carb.
you said "the carb was bought new"
this could be the reason: a new carb comes jetted for a certain application which does not match with your engine.
e.g.: original ford jetting was setup with a proper airfilter, seven-type cars run different filters and should be jetted accordingly.
snippy - 27/4/14 at 08:57 PM
Thanks to all for throwing in suggestions. I`ve stripped carb and measured float heights, rechecked valve clearances, checked fuel flow, checked
timing etc etc. So,after much head scratching I bought another new set of standard HT leads from my local motor factor and some new NGK spark plugs.
Fitted the new leads and plugs tonight and there is a marked improvement. My strobe light is picking up a better signal from no.1 lead now too so the
new Accuspark HT leads I bought must have been the problem all along. Very annoyed about this! It`s running so much better now. Couldn`t test drive it
tonight due to it raining but I feel sure it will be better now. Just goes to show you, sometimes basic OE parts are all you need!
Thumbs up chaps!
alfas - 28/4/14 at 08:01 PM
the pick-up for the strobe lamp shouldnt worry you:
i purchased some, rather expensive, HT leads and after installing i could not use my strobe light anymore...but!!! everything else improoved...
means the strobe light isnt an indicator.
BaileyPerformance - 28/4/14 at 10:32 PM
quote:Originally posted by alfas
the pick-up for the strobe lamp shouldnt worry you:
i purchased some, rather expensive, HT leads and after installing i could not use my strobe light anymore...but!!! everything else improoved...
means the strobe light isnt an indicator.
Check your HT leads are resistive type, NOT copper core.
Also, you must use resistive plugs with electronic io ignition.
One comment, from past experience, cheap eBay electronic ignition is worse that a well setup points system.
Also, check your dizzy for wear - these engines are old and aftermarket dizzy's can be poor.
Best option is megajolt.
threadbare wallet - 29/4/14 at 05:25 AM
Whats wrong with copper core leads?
BaileyPerformance - 29/4/14 at 08:53 AM
quote:Originally posted by threadbare wallet
Whats wrong with copper core leads?
The HT lead resistance should not be too low for the following reasons....
If the lead resistance is low, when the plug fires, the energy from the coil is consumed very fast - the current at the plug will be higher but for a
shorter duration, some resistance in the system lowers the peak current but allows the discharge from the coil to be slower therefore a longer
duration spark is produced (this is what you need for decent combustion)
Very fast discharge and high peak currents can cause reflections in the HT leads, crossfire and ignition amplifier damage.
As above, can also generate high spikes if RF noise that can effect any electronics in the car.
In most electronic systems maximum power transfer from one device to another required impedance matching, NGK plugs have a 5k resistor inside,
magnicor leads have a spiral core with resistance of a couple of hundred ohms per foot. Add this together and you get about 8k with is the secondary
resistance of the coil. This is not a coincidence.
OEM HT leads work fine, but often have very high resistance for better EMI, the down side is when they get old, the resistance gets too high.
mcerd1 - 29/4/14 at 11:08 AM
quote:Originally posted by Smoking Frog
quote:
I've done that, having found TDC you always get a 'Dead' area where the pulley will move without TDC moving. I've marked this dead
area to create my pulley mark
there are tolerances on every part of the engine - so true TDC will almost never be where the timing marks on the pulley say it is (even on a brand
new engine)
here's the locost / simple way to accurately find true TDC, you'll need this as a reference for setting your cam and ignition timing:
but remember that due to the tolerances on every part the engine may run better with cam and ignition timing a few degrees off what it says in the
books, even when the TDC mark is spot on - but the only way to find out is trial and error...
in fact you could just forget the mark and keep adjusting the timing a few degrees either way until it runs right by trial and error
my old fiesta (very similar to the x-flow) ran best about 10° - 12° on the marks, but I never bothered to find true TDC so I can't tell you how
far off the marks were and how much was due to the fact it was running on 98 octane LRP rather than than the 4 star it was designed for. - I just
tuned it by ear then used the strobe to find out were that was for the next time
[Edited on 29/4/2014 by mcerd1]
Fatgadget - 29/4/14 at 11:54 AM
quote:Originally posted by threadbare wallet
Whats wrong with copper core leads?
TVI!
Yes television and radio inteference was the bug-bear of copper HT leads I was learned to believe.Though in these days of universal almost bomb-proof
digital comms that sort of inteference is no longer an issue- No?
BaileyPerformance - 29/4/14 at 06:40 PM
Yes television and radio inteference was the bug-bear of copper HT leads I was learned to believe.Though in these days of universal almost bomb-proof
digital comms that sort of inteference is no longer an issue- No?
Digital electronics can suffer from EMI just as much as analogue, noise via power/ground cables can really upset processor based devices.
For example, a current loop communication system such as 4-20mA as used in process control in every power station is less susceptible then serial
RS232 or even RS485
BaileyPerformance - 29/4/14 at 06:45 PM
but remember that due to the tolerances on every part the engine may run better with cam and ignition timing a few degrees off what it says in the
books, even when the TDC mark is spot on - but the only way to find out is trial and error...
in fact you could just forget the mark and keep adjusting the timing a few degrees either way until it runs right by trial and error
my old fiesta (very similar to the x-flow) ran best about 10° - 12° on the marks, but I never bothered to find true TDC so I can't tell you how
far off the marks were and how much was due to the fact it was running on 98 octane LRP rather than than the 4 star it was designed for. - I just
tuned it by ear then used the strobe to find out were that was for the next time
[Edited on 29/4/2014 by mcerd1]
Agree with the above just to get it running at idle, but not a good idea to assume its all fine and OK to drive, tuning engine by guesswork normally
ends in tears.
Anyway, as you said you should be able to get it running by fiddling with the dizzy for best idle.
If no luck bin the ignition amp and go back to points if possible or buy a decent electronic system. Best solution all round would be megajolt.
mcerd1 - 30/4/14 at 01:54 PM
quote:Originally posted by BaileyPerformance
Agree with the above just to get it running at idle, but not a good idea to assume its all fine and OK to drive, tuning engine by guesswork normally
ends in tears.
fair point, when i was tuning mine by ear it was on the assumption that it was pretty close to start with
mine was a 100% original car with everything working perfectly and exactly as it left the factory - it only had 25k on the clock when I got it at 21
years old (and I knew were it had been since new)
without modifying it all I could do was set the advance with the vac. advance disconnected and trust that the dizzy was working as it was intended -
then see how it went and adjust it a couple of degrees if needed (mainly to allow for the weird LRP fuel that you can't even get now)
