misfire/ hesitation

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misfire/ hesitation

Postby lotustonybassplayer » Wed 25.05.2016, 16:03

Had the problem of appearing to fire on 2 cylinders when getting hot and ran ok when restarting from cold. Then it did not run from cold :( put it down to fuel injectors . As other people have had the same symptom and addressed this by replacing the injectors. All 4 plugs firing ok, tho 1+2 were sooty 3+4 right colour. so replaced injectors still not right have now replaced cts and plugs. better, idles and starts ok but hesitates/misfires slightly have not done timing as i have to borrow a timing light. but marked the cas position and advanced retarded it did not seem to make a difference put it back to its original position . Not had any cel faults . I checked all sensor connections, no corrosion sprayed them all with switch cleaner anyway. Any other pointers gratefully received . :)
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Re: misfire/ hesitation

Postby Candles » Wed 25.05.2016, 18:08

Timing first, then I think my first check would be coils and leads. Next I would plug in Elanscan and look for any odd readings. I'd also go around the engine and check all the earthing points - there is an electronic one on the back offside of the intake plenum that grounds many of the ECU-related things. If this is rusty/loose/bad it makes the engine control go absolutely mental.

Then, and this is a wild stab in the dark; but it could be the fuel pressure regulator on the end of the injector rail? There's a check procedure in the manual; you need a pressure gauge.
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Re: misfire/ hesitation

Postby lotustonybassplayer » Thu 26.05.2016, 16:28

Little update. The car has MSD coil packs any known issues with these ? has got magnecore KV leads. I seem to be getting spark at all 4 plugs with my inline tester. ordered a timing light so will try base timing at the weekend. the throttle body had a film of oil in it is this normal ? from the emissions gizmo i'm guessing ? none in the intake hose so hopefully not coming from the turbo ,I took out the MAT sensor after discovering this, it was caked in it, so gave it a clean with brake cleaner and refitted it . ordered a new one and some coils and a new pressure regulator from rock auto.
Last edited by lotustonybassplayer on Thu 26.05.2016, 17:00, edited 1 time in total.
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Re: misfire/ hesitation

Postby Giniw » Thu 26.05.2016, 16:42

Candles wrote:Timing first

:agree:
Have you checked the base timing?
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Re: misfire/ hesitation

Postby Elanlover » Thu 26.05.2016, 17:37

lotustonybassplayer wrote:Little update. The car has MSD coil packs any known issues with these ? has got magnecore KV leads. I seem to be getting spark at all 4 plugs with my inline tester. ordered a timing light so will try base timing at the weekend. the throttle body had a film of oil in it is this normal ? from the emissions gizmo i'm guessing ? none in the intake hose so hopefully not coming from the turbo ,I took out the MAT sensor after discovering this, it was caked in it, so gave it a clean with brake cleaner and refitted it . ordered a new one and some coils and a new pressure regulator from rock auto.


I have MSD coils and KV leads. Been great for me for many years.
I do whatever my Rice Crispies tell me to do
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Re: misfire/ hesitation

Postby lotustonybassplayer » Thu 26.05.2016, 17:39

Ok car will start and run with 2+3 quite smoothly :shock: with 1+4 it will start but run rough, pointing towards the coil then, or maybe a lead breaking down ?
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Re: misfire/ hesitation

Postby lotustonybassplayer » Fri 27.05.2016, 16:53

I removed the CAS today and the reflector wheel has some rubbing marks all round the the center of the circumference it has been rubbing against the other sensor not the HES. i believe for the tacho guess this is not normal and should not be touching :?: Also did paperclip test, no fault codes logged.
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Re: misfire/ hesitation

Postby Brit-Car-Nut » Fri 27.05.2016, 19:32

The HES is basically the cam sensor and the "other" sensor is basically the crank sensor. They are both adjustable, so adjust the clearances per this posting:
viewtopic.php?f=8&t=24681&p=311921&hilit=cam%2A+clearance#p311921

There is always the Ignition Control Module that might be suspect. Maybe remove it and check all of the connection plug areas (I have several used ICMs that have heavily corroded connection pins for the low voltage connection plugs) as well as the contacts for the coils. You could always swap coils and see if the problem moves to the other pair of cylinders...
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Re: misfire/ hesitation

Postby lotustonybassplayer » Fri 27.05.2016, 20:06

Thanks for the link John, will get it off tomorrow and set it up, I have one of your ignition modules waiting to go in, my car has air con so a bit more awkward to get at, was taking the belt and braces approach and replace the module and coils when they turn up, so i only have fiddle with it once. :evil: I fitted new leads today and can rule them out as the problem.
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Re: misfire/ hesitation

Postby Candles » Fri 27.05.2016, 20:33

Oil in the intake plenum is completely normal - as well as the positive crankcase ventilation (emissions gizmo you mention) there is the added oil from any leaking from the turbo bearing!
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Re: misfire/ hesitation

Postby lotustonybassplayer » Fri 27.05.2016, 20:51

Thanks Candles, at least the oil coating is a normal occurrence then, and nothing to worry about :)
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