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Old 04-13-2006, 11:38 AM
dancerman
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Engine missing when cold

I have a '90 Ply Laser (see avatar). It has a 2.0 L turbo engine and 5 speed. It's not driven often (only 56k miles). Lately, the engine misses when cold if the car has sat for a few days or a week. As soon as the temp. comes up all is fine. I replaced the plugs and wires but no change. No CEL and runs excellent when warm. Any suggestions for me? I am going to run a bottle of FI cleaner through it. Maybe that will help.
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Old 04-13-2006, 12:45 PM
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If you have a distributor cap maybe, squirt some wd-40 in there once and wipe it out with a paper towel and see if it's moister or humidity related. You also want to make sure there is no rust or corrosion forming on the coil end(s) or distributor cap ends.
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Last edited by justen; 04-13-2006 at 08:32 PM.
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Old 04-13-2006, 09:18 PM
dancerman
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It's got a coil pack which I had thought about. Can't really examine the bugger without pulling the intake. Also kinda pricey to replace without definite reason. Maybe I'll have to dive into it. Thanks Justen.
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Old 04-14-2006, 06:25 AM
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Look for the easy stuff first. Check for vacuum leaks. A cold engine exagerates a miss and it could also be a leak, when cold, and then as the engine warms up and expands, the leak is sealed again.
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Old 08-14-2006, 10:35 AM
dancerman
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I need to bump this thread for help

I'm still having problems with this car. I replaced the coil pack and the ignition module and no change. Over the summer the cold miss has become a cold and hot miss. This is only at cruise...when you accelerate it doesn't buck or miss. No CEL and good mileage. I have noticed that the exhaust smells like stinky sulfer. Could it be the EGR system?
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Old 08-14-2006, 10:46 AM
dougbfresh dougbfresh is offline
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How does it idle?
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Old 08-14-2006, 02:00 PM
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Could be egr, but once a egr goes, It's continuously. Meaning it would miss all the time, especially acceleration. But it's also possible it's sticking on ya. If you decide to look at the egr valve, also check your vacuum hose. and make sure thats not the root cause of trouble as well.
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Old 08-15-2006, 06:25 AM
dancerman
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Originally Posted by dougbfresh
How does it idle?
Good question. When I first start it, the idle jumps all over and it's a bit high. It climbs to about 1800 rpm then drops quickly to about 1200 rpm and cycles like that until warm. But once at operating temp it idles perfectly smooth at 700 rpm with no fluctuation. The problem occurs when taking off (very mild acceleration) or driving at cruise the engine bucks (like a miss) as if it's cutting out. The bucking is severe when the engine is not completely warm. Even if the engine temp drops a tiny bit like when you stop somewhere for 20 minutes or so it will buck until the temp comes back up. At operating temp it still bucks but it's mild; almost not noticable at times). If you moderately or fully get on it... the problem goes away. This engine has a turbocharger and shows good boost and power. What makes this hard to figure out is no CEL and so no codes to read. I am thinking it could be the computer. These DSM (diamond star motors) computers are known for leaking capacitor problems. This car is 16 years old.
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Old 08-15-2006, 06:28 AM
dancerman
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Originally Posted by justen
also check your vacuum hose. and make sure thats not the root cause of trouble as well.
I've looked for obvious hose leaks. So many hoses..... guess I'll have to look some more.
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Old 08-16-2006, 06:23 PM
dancerman
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I haven't found anything broken yet. I checked out as many sensors as I could. But with no CEL I didn't expect to find a bad one.

I'm about to take off the throttle body to clean it and the idle air motor. Then I can get at the EGR to clean and test it.

What's the chances this could be a bad fuel injector? Can a sick one cause the engine to buck (sputter, sputter) at cruise?
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Old 08-16-2006, 06:59 PM
dougbfresh dougbfresh is offline
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Get a vacuum guage on it, takes 2 minutes and could save you alot of time and $$$.
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Old 08-16-2006, 08:47 PM
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yes a fuel injector can make it buck, even a weak fuel pump can make it buck also.
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Old 08-17-2006, 07:35 PM
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Hi Having no codes basically tells you all sensors are working,if in fact the computer is.Pull off any sensor wire that is handy while the car is running to produce a false code,see if your light comes on then run a code check.This should exclude the computer as being at fault but no gaurentee.If this works out you are now back to basic troubleshooting to things not implusing to the computer,Like fuel pump ,fuel regulator,vaccum leaks, Ign componants ,air + gas filter,pcv,calaltic convertor or base timing.It's hard to think out of the box when they have computers,but that's how they get fixed.Cleaning the throttle body would be a very good start from what you have discribed
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Old 08-18-2006, 06:30 AM
dancerman
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Quote:
Originally Posted by justen
yes a fuel injector can make it buck, even a weak fuel pump can make it buck also.
This is the weirdest darn thing. Last night after driving an hour or so (with the mild bucking at cruise) .... I stopped for about 1/2 hour. When I started the car up it idled fine but as I started to drive it stuttered and bucked like it was not firing on all cylinders. After a mile or so it was OK... er mild bucking but drivable. Then I drove an hour home. No CEL just moody. I'm gonna take the injectors out. How should I clean them if they need it? Can they be tested somehow?
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Old 08-18-2006, 06:35 AM
dancerman
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Originally Posted by Ben There
Hi Having no codes basically tells you all sensors are working,if in fact the computer is...........It's hard to think out of the box when they have computers,but that's how they get fixed.Cleaning the throttle body would be a very good start from what you have discribed

Thanks Ben.... I know these DSM computers are notorious for leaking capacitors. Maybe mine are starting to go. I could pull it and look inside. I really need to find evidence of a bad part as they are all so expensive to replace. I did put in plugs, wires, coil pack and ignition power module and no change (except wallet lighter).
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