Mechanics

ROUGH IDLE AFTER REPLACING TIMING BELT

1998 Plymouth Breeze

Engine Performance problem
1998 Plymouth Breeze 4 cyl Two Wheel Drive Automatic 147000 miles

Hi, Just replaced my water pump/Timing belt on my 98 plymouth breeze 2.4L DOHC. Thought I aligned timing marks correct on intake/exhaust sprockets & crankshaft TDC marks, but has a rough idle, wants to stall when you take foot off gas when driving, but has plenty of power at all higher speeds.
Also, checked for vacuum leaks & replace a couple of hoses, thinking the marks still might be off a smidge, but not sure. Thank you, Keith
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Kpk3327
July 15, 2010.




If you put the no.1 piston on its compression/TDC and line everything up as seen below

Disconnecting the battery can throw off the idle air control valve its probably going thru a relearning process.


http://www.2carpros.com/forum/automotive_pictures/12900_timing_36.jpg


Rasmataz
Jul 15, 2010.
Thank you for responding so quickly, I drove around for about 30 minutes and now the check engine light came on, pulled a code " Engine Running Rich" .
Engine has plenty of power, but as soon as you are at a stop it is " Idling Rough".
As far as the re- learning process? How long can that take?
Thanks Again! Keith

Tiny
Kpk3327
Jul 15, 2010.
Probable causes of an engine running rich are as follows and will make it run rough

1. Excessive fuel pressure can be cause by restricted fuel return line or defective fuel pressure regulator.
2. Defective Oxygen Sensors.
3. Leaking injectors and fuel pressure regulator.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.
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Rasmataz
Jul 15, 2010.
Thank you, I will take into consideration, this rough Idle only started after changing belt, 1st & 2nd attempt of lining up timing marks caused the engine to not start & backfired. 3rd attempt, the engine started and drives good, but now idles rough.

What are your thoughts on timing marks being slightly off, can car have plenty of power & still have a rough idle? Almost like a misfire.
It is my understanding this set up for this engine is very difficult because of the way the engineers designed the location of the marks on the teeth.

Tiny
Kpk3327
Jul 15, 2010.
The only way to find out is to open it back up-try checking the ignition timing if its correct

Rasmataz
Jul 15, 2010.
Thanks, I will check it out. Appreciate your help!

Tiny
Kpk3327
Jul 15, 2010.

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