Not my Noble but, need help with a project !!! some synergy
Discussion
I have acquired a 1991 AM Virage, just spent a few weekends replacing 6m of vacuum hose in and around the engine (common problem on Virage was plastic and perished within a few years). So all done, car now running, the problem, it idles fine but will not hold revs above 1000 rpm, every time you gradually raise the rpm say to 3000 it drops back to idle or stalls !? Any ideas ?
The reason I posted on here is that being Ford ish the fuel line is very similar and I think the pump is the same type ish Bosch 044 and you are all very clever at solving problems, handsome, suave and sophisticated etc... ;-). I guess may not be something in the fuel line, just a hunch.
Not really done any tests yet as only found out last night but, be good to get some pointers before I get stuck in.
Cheers
Mark T
The reason I posted on here is that being Ford ish the fuel line is very similar and I think the pump is the same type ish Bosch 044 and you are all very clever at solving problems, handsome, suave and sophisticated etc... ;-). I guess may not be something in the fuel line, just a hunch.
Not really done any tests yet as only found out last night but, be good to get some pointers before I get stuck in.
Cheers
Mark T
Thought you could fix anything though? 
Never heard of a problem like that before with a car so I'll have a guess to provoke some thought and get the ball rolling.
Have you had someone check the voltage at the fuel pump when the cutting or going back to idle happens? It might hold answers. Maybe a dodgy relay is tripping out.
Also what about engine earths are they in good condition?
Check the vacuum lines for leaks or in case the positioning of them are near hot manifolds or anything like throttle linkages that could be snagging as it moves and kinking the hose.
Hope its an easy fix for you
Graham
Never heard of a problem like that before with a car so I'll have a guess to provoke some thought and get the ball rolling.
Have you had someone check the voltage at the fuel pump when the cutting or going back to idle happens? It might hold answers. Maybe a dodgy relay is tripping out.
Also what about engine earths are they in good condition?
Check the vacuum lines for leaks or in case the positioning of them are near hot manifolds or anything like throttle linkages that could be snagging as it moves and kinking the hose.
Hope its an easy fix for you
Graham
No MAF, it does have TPS which is set to 150mV +-5mV at close, it also has 2 x MAP/APS, its an overly complex system it runs 2 of everything including 2 x ECU's I guess in 1988 they did't have 1 ECU that did more than 4 cylinders, its the same set up as Early Cosworth's but x2 the only common sensors are TPS and crank sensor which go to the master ECU.
I'm confident that vacuum pipes are all good as i tested all with Vacuum pump/gauge before closing up the plenum chamber.
Good idea re check pump voltage while running, should be easy to do.
I'm confident that vacuum pipes are all good as i tested all with Vacuum pump/gauge before closing up the plenum chamber.
Good idea re check pump voltage while running, should be easy to do.
Fixanything said:
No MAF, it does have TPS which is set to 150mV +-5mV at close, it also has 2 x MAP/APS, its an overly complex system it runs 2 of everything including 2 x ECU's I guess in 1988 they did't have 1 ECU that did more than 4 cylinders, its the same set up as Early Cosworth's but x2 the only common sensors are TPS and crank sensor which go to the master ECU.
I'm confident that vacuum pipes are all good as i tested all with Vacuum pump/gauge before closing up the plenum chamber.
Good idea re check pump voltage while running, should be easy to do.
Does it have an emissions air bleed solenoid thingy (technical term) could be sticking open.I'm confident that vacuum pipes are all good as i tested all with Vacuum pump/gauge before closing up the plenum chamber.
Good idea re check pump voltage while running, should be easy to do.
Didn't the Webber Marelli injection system have a few gremlins in the beginning?
TuxMan said:
Sounds fuel related , any idea what fuel pressure is ??
Simon, I'm suspecting pump, just off to get some fittings to test fuel pressure. If I turn engine off and leave it a few seconds when I restart I get a few seconds of power then it just gradually drops away to idle a wont move from there, if you try and plip up it hesitates and almost stalls.Thanks to all for the help so far.
Mark T
So convinced the pump is OK, i put everything back together but, run the pump directly of a spare battery while charging it from the Virage battery. Guess what, works perfect. So all that's left now is the pump relay and the alarm system !!! long day.
The only problem I have is why I did not see this on the voltage check earlier today, may be if its a fast drop the digital volt meter may not may not have displayed it!
Off to find the relay
Mark T
The only problem I have is why I did not see this on the voltage check earlier today, may be if its a fast drop the digital volt meter may not may not have displayed it!
Off to find the relay
Mark T
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