Cheers in advance,
Long story short as some of you may know I bought one off ebay unseen, my old man had one in the day and it seemed a good idea on ebay on a Friday
night! As it happens I dropped lucky and its the only solid maestro left, and ran fine.having sat on my drive for afew years ive finally got it on the
road with no real issues but now its been going it has afew
Mainly a missfire under load.if anyone were to drive it you'd say plugs leads etc, its had them, dizzy rota atm, no real difference.nicked a fuel
pump off another car I know is good, fuel filter and now had my injectors checked(for a pint). 1 injector isn't spraying the same pattern as the
others but delivering the same amount of fuel. This I suspect isn't helping and neither is the rattling cam but the way it drops from 4 to 3
cylinders in one hit then jumps back to 4 like a switch Iim at a loose end, and tighter than a ducks arse, as its cost nothing so far And was jjust
trying to get the winter out of it before project sleeper!
Anyone who can remember anything else to check before I give in and throw the tomcat in it(or happens to have an ecu lying around) im all ears!
Chris
Check both the crank and camshaft sensors, I had a Montego and the Crank sensor was the culprit, car ticked over fine ran okay until you dropped the loud pedal. Removed the senso cleaned it with a good dose of white spirit ran fine after that
Had the twin carb and efi , efi used to miss fire due due leafs around the ecu
quote:
Originally posted by kj
Had the twin carb and efi , efi used to miss fire due due leafs around the ecu
Cheers, ive been all over it, the only thing ive not done is the knock sensor really, doesn't seem to make a difference if its plugged in or not,
should it? I know it affects the timing but cant believe it would drop just one cylinder? If I can't get to the bottom of it this week I'll
try blag dad for his Gilbern for the winter!
Chris
Does it do this with the engine Hot and also when its Cold ?
When it happens how long does it last for ?
Have you checked the main connector to the ECU and given it a spray of contact cleaner ?
quote:
Originally posted by slingshot2000
quote:
Originally posted by kj
Had the twin carb and efi , efi used to miss fire due due leafs around the ecu
Are these the same "leafs" British Rail used to complain about for causing delays; IE, Delay due to leaves on the line . ????
Its more prone to it when its hot, but has got to the point I don't like driving it too far now.have never got it to start missing hot or cold
long enough free reving in the shed when I have gear and eyes to see whats going on tho. Can run gently up to the limiter while driving without it
missing a beat, sometimes floor it and its ok, but most usual way it kicks off is more throttle than needed about 2k revs and it runs on 3 for afew
minutes.
Chris
Remember these well. Came 3rd in class on the RAC in one a good while ago. Sounds like fuelling. We used to get probs with them when very hot which
was fuel vapourising in the rail. Overcame that by by-passing the resistor in the fuel pump supply which was only there to keep the noise of the pumps
down.
HTH
Mike
Is it one of the ones where the car used to talk to you? The idiot lights and fluid warnings had voice announcements.
I was sure it was one of these that a mate bought with no stereo fitted. Plugged in the proper stero once it was on his drive and it then spent 10
mins running through all that was wrong with the car.
Sounds like a blocked fuel line or tank not venting it. Could also be the fuel pressure regulator.
Crank sensors on Rovers of this era do give trouble, apart from crud build up an intermittent connection is a common fault but that normally shows up
when moving of from rest.
No don't recall these having a knock sensor.
The early cars used a Motorola injection system with a Hitachi Hot Wire sensor and a separate Lucas ignition ECU, latter version was Rover Motorola
MEMS. The Hotwire system tends to become over rich as the sensor ages.
I seem to recall these, and the Montegos, having issues with the spark plugs. The AR dealer I worked at had to swap from the Unipart supplied recommended plug, to a different grade.
I had a two year old MG Maestro many years ago and don't mind saying I really liked it. It was better to drive than the golf gti of the same era and underestimated. Quality was pretty crap but I did 50k miles n mine without any problems.
Cheers for the suggestions so far but after another afternoon tinkering im no better off!
So far its had
Recent fuel pump and filter
Leads plugs coil dizzy rotor arm and coil
Injectors cleaned and checked
Crank sensor cleaned (dont know how to check it?)
Throttle position sensor checked, linear resistance through range of pot
Temp sensor checked, resistance drops as engine warms up
Checked emissions today, co is around 6, was 2 at mot,adjusting mixture screw has little effect?
Hc was around 800
It still drops to 3 cylinders when accelerating. Then runs happily on 4 on light throttle. Im out of ideas!
diagram
diagram 2
[Edited on 6/12/14 by StrikerChris]
[Edited on 6/12/14 by StrikerChris]
Most likely of no use but something else to check. My Dad had a Montego which had a habit of running on 3 cylinders. It was a faulty ECU or the distributor (can't remember which). I do remember the distributor shaft was bent (the rotor arm seems to get stuck on the end of the shaft requiring a lot of leverage to remove, resulting in the shaft getting bent). Should be easy to check before trying to find a new one. Other than that check ECU.
Yeah cheers, dizzy rotor arm seem ok and im begining to think one of tbe ecu's myself which I can imagine being a nightmare to get hold of the right kind thesedays, they wweren't all the same apparently!