1989 Pontiac Firebird Jerking

TAYLOR6220

MEMBER
1989 PONTIAC FIREBIRD
6 CYL
2WD
AUTOMATIC
120,000 MILES

I was told the car needed a tune up. The spark, plugs, wires and coils were replaced. The oil was also replaced and the filter changed. The car still jerks. It is a bumpy takeoff and it also does it when the car is idling - making the check engine light come on. When the car was first assessed, the code indicated the spark plug #4 and #5 were bad, but that did not correct the problem. The car seems to JERK and it doesn't seem like it takes off slower than normal. It does not do it all the time. There seems to be no modifying factors to when it happens. I have noticed it when the car is cool and after idling for a period of time. Please help!

Sunday, July 27th, 2008 AT 9:04 AM

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

Cross these two terminals as shown, then turn the key on. Count the flashes, a 22 will flash as 2 flashes then a short pause, then 2 flashes, if more than one code is stored, the pause will be longer. The codes will display three times and end with 12. Write them down and post here. This connector is right under the middle of the dash...You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs!

Was this

answer

helpful?

Yes

No

Sunday, July 27th, 2008 AT 9:08 AM