Jerky Jriving
Thread Starter
Safety Car
Joined: Jul 2003
Posts: 4,928
Likes: 1
Jerky Jriving
I've installed a ZZ4 in my 89 coupe. The car used to drive smoothly through the neighborhood at low speeds. After installation of the motor, the car is very jerky at low speeds and I have to keep my foot on the throttle or dis-engage my clutch to coast down the street.
I've installed all new U-joints while in there, which should help tighten up the drive train.
My questions are:
1. Can this problem be fixed in the tune?
2. I know I need a new clutch, could that be the problem?
I've installed all new U-joints while in there, which should help tighten up the drive train.
My questions are:
1. Can this problem be fixed in the tune?
2. I know I need a new clutch, could that be the problem?
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
As agent 86 mentioned, a tune will probably take care of your problem. You are running a stock tune with a motor that has more cam and less vacuum so spark/fuel requirements are different.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 414
From: WV
The ZZ4 is a very different motor from the stock L98. More then 100 hp different.Hook up a scanner to it , the ECM is probable going crazy trying to compensate...WW
Last edited by WW7; Nov 5, 2009 at 07:31 PM.
Thread Starter
Safety Car
Joined: Jul 2003
Posts: 4,928
Likes: 1
Thanks guys for the comments.
I've already had the tune. I was asking because I will take it back to him to fix that in the tune if that's what it could be.
Dave, I need to get a timing tape to wrap around the balancer. I used the old balancer and the new timing cover doesn't have the timing marks, just a plastic bump. I'll check it tho.
I've already had the tune. I was asking because I will take it back to him to fix that in the tune if that's what it could be.
Dave, I need to get a timing tape to wrap around the balancer. I used the old balancer and the new timing cover doesn't have the timing marks, just a plastic bump. I'll check it tho.
Le Mans Master
Joined: Sep 2005
Posts: 6,551
Likes: 36
From: Jenks OK
If you've got a distributor wrench you might just mark the position and try moving it a little to see if it smooths out a bit. Have you also checked vacuum? If you've got a vacuum leak it'd idle worse. Sorry it's not running better, I'm hoping the weather is nice this weekend so I can take mine out of the garage.
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Thread Starter
Safety Car
Joined: Jul 2003
Posts: 4,928
Likes: 1
It's idling just fine. I do need him to readjust the tune for when I turn the AC on. If I can just find time to get the car down to him, that's a big problem for me too!
I do know someone with datalog equipment. I'll give him a call and see if we can pull some info. What should I be looking for specifically?
I do know someone with datalog equipment. I'll give him a call and see if we can pull some info. What should I be looking for specifically?
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
It's idling just fine. I do need him to readjust the tune for when I turn the AC on. If I can just find time to get the car down to him, that's a big problem for me too! I do know someone with datalog equipment. I'll give him a call and see if we can pull some info. What should I be looking for specifically?
The AC is an easy fix, add more counts to the IAC /AC ON, (stock setting is 5 counts in the tune). You can also add some RPM (when AC on, both in the tuning properties) which will fix the AC idle/in gear situation.
