1988 Vogue 3.5 ignition problem

1988 Vogue 3.5 ignition problem
[FONT=&quot]The car will start but as soon as I take my foot off the accelerator the engine runs down and stops, if I keep the revs up the engine starts to hunt, but go out and start from cold and it will tick over fine for about 5 0r 6 minutes, the airflow meter is ok I changed the temp sensor, this problem has been a gradual thing getting worse as weeks go by until now I can’t keep it going. In the past the car ran fine but occasionally it would suddenly start to hunt while driving along I would stop for about 10 minutes then restart and away I would go again. Anyone help with this one

I have been looking round the car this morning and trying to see if I can find anything, I did find one wire loose on the distributor, put another connector on it and pushed it home again, but no diffrence, I changed the plugs, as I say start from cold runs fine but within minutes it's missing again

Do you think its the air bypass valve?

Just ordered another one from paddocks for 1990 classic £55

fett said:

Do you think its the air bypass valve?

Just ordered another one from paddocks for 1990 classic £55

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No appears ok but thanks for you input much appreciated

A long shot perhaps but if you can get the thing started and ticking over, stick a strobe light on it and see if the timing wanders. Could be a stretched timing chain but this doesn't (as far as I know) cause significant hunting.

You might also want to strip and clean the plenum and also the throttle butterfly. Make sure everything is clean and that the throttle linkage moves freely. Re-assemble and make sure there are no air leaks.

Hope that helps.

Cold start sensor faulty?? This would keep the mixture "Rich".
Are the plugs "Sooty"?

Irishrover said:

Cold start sensor faulty?? This would keep the mixture "Rich".
Are the plugs "Sooty"?

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Did they still have that on the 3.9 model with hotwire? if so where is it?

I have the same prob but not as bad.

I'm going back a bit now since I had my Classic Vogue but I feel sure it's on the inlet manifold front passenger side. I will have a look tomorrow morning to see if I can get more info.
................Unless someone comes along and answers the question before I do.

Thanks!

fett said:

Did they still have that on the 3.9 model with hotwire? if so where is it?

I have the same prob but not as bad.

Click to expand...

Cold start injector as you look at the engine from front of the car, the cold start injector is on the left hand side of the plenum near the top, aprox two thirds back from front of plenum, if you have it there pull wire off and try engine, no change not injector, I put my cold start injector on a manual switch

classic kev said:

A long shot perhaps but if you can get the thing started and ticking over, stick a strobe light on it and see if the timing wanders. Could be a stretched timing chain but this doesn't (as far as I know) cause significant hunting.

You might also want to strip and clean the plenum and also the throttle butterfly. Make sure everything is clean and that the throttle linkage moves freely. Re-assemble and make sure there are no air leaks.

Hope that helps.

Click to expand...

Thanks for the input all answers are welcome many thanks

fett said:

Did they still have that on the 3.9 model with hotwire? if so where is it?

I have the same prob but not as bad.

Click to expand...

As far as I know there is no cold start injector on a 3.9 and I think that the air flow meter controls the input to the ecu based on temperature differential together with inputs from coolant and fuel thermistors and in this way, the ecu adjusts the length of the injector pulse for cold start. Not at home this weekend but will check later if you like.

classic kev said:

As far as I know there is no cold start injector on a 3.9 and I think that the air flow meter controls the input to the ecu based on temperature differential together with inputs from coolant and fuel thermistors and in this way, the ecu adjusts the length of the injector pulse for cold start. Not at home this weekend but will check later if you like.

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Thanks that would be great, didnt think mine had one.

Does the ecu get its temp reading form the coolant temp sensor then?

fett said:

Thanks that would be great, didnt think mine had one.

Does the ecu get its temp reading form the coolant temp sensor then?

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Yes, the coolant thermistor (not the temp. gauge sender) feeds into the ecu, if you look in Haynes/Rave/workshop manual you should fnd a complete schematic. In Haynes it tells you how to test coolant thermistor which basically feeds a variable voltage because its' resistance changes between hot and cold conditons, the ecu then reads this voltage and maps the injection accordingly although the 14CUX only has fixed maps rather than being adaptive in the way later Gems and Thor systems are.

Have a read of this one.

http://www.landyzone.co.uk/lz/f42/3...-hot-87155.html?highlight=clean+stepper+motor

Have a look at this.

http://www.landyzone.co.uk/lz/f42/m...rich-83342.html?highlight=clean+stepper+motor

Had a good read, it could be that I need to follow that full procendure for base idle, I was hopig that the new stepper would make some differnce, what I really need to know is if you unplug the wires to the steper at idle shoudl it make a differnce?

From A temperature sensor, yes.

fett said:

Had a good read, it could be that I need to follow that full procendure for base idle, I was hopig that the new stepper would make some differnce, what I really need to know is if you unplug the wires to the steper at idle shoudl it make a differnce?

Click to expand...

Setting base idle is quite easy and costs nothing. Make sure your ignition timing is correct and that the throttle butterfly is correctly set.