Vibration issue

9

93LINCMK8

Registered
I just changed the plugs and wires due to a slight miss at take off. There is still an issue of a vibration in park with the rpms at around 1300.

Technically it's there all the time, it's just more pronounced at 1300.

Also, what would cause the check engine light to come on right after a WOT shift to second and then shut off after about 5-10 sec? Could it be a TPS or IAC or both or what?

Also, would an external cooler stop the flaring rpms when returning to throttle after coasting?
 
Why don't you scan the codes?

Could be one of 100 things... You're lucky enough to have CE light.
 
Vibration in park.....it has to be a balancing issue, like a bad harmonic balancer or a bad motor mount. There is practically no "load" on the engine, so anything related to spark/fuel/air isn't "really" going to play a factor. Try loading the engine with your foot on the brake and it in drive. Rev it to 1300 rpms and see if the vibration is still there, worse, or non-existant.

The CE light could be more like one of 100,000+ things, heck maybe a million. You could have a simple coil pack failure at WOT, a fuel pump issue, an ABS issue, a continumtransfuctioner problem, or even a bad needle sticking device. :) Go pull codes.


The flaring of the RPM's is a common issue with our cars, it doesn't hurt anything and with all my mods/repairs I couldn't make it better. I noticed it a lot more when I cut off my mufflers because I could actually "hear" the engine flaring instead of just seeing it in the Tach. Again....its not hurting anything nor will a external cooler change it.
 
Balancing issue, that's what I figure. It doesn't feel or sound like a miss, it does feel more like somethings off balance.

As for the flaring, I thought maybe there was low pressure due to clogged cooler lines in the radiator. The radiator wasn't changed out along with the tranny rebuild. I finally met the guy that actually rebuilt it and took him for a drive so he could see. He suggested the cooler install. he also doesn't have a clue about the "pumping" action when slightly letting off the brake at a stop. It only does it in 1st and drive, not 2nd.
 
Oh ok, this is that f'd up transmission thats been built like 3 times.....

I definitally suggest a stand alone cooler, on any transmission, but I don't think that will fix your "problem".

Being that its a 93, you could have a worn balancer or motor mount. Watch the pullies while its idling, do you see any wobbling? Power brake the car and have someone watch the engine to see if its lifting on the driver side, this will tell you if the motor mount is weak.
 
The motor mount is definitely shot. Could that also cause poor throttle response? Can it put the TPS out of wack?

It almost hits 3,000 rpms shifting to second at medium throttle. It also seems to hesitate, or flatten out for a second before shifting to second.

I have the bottom 1-2 spring out. Does this cause it to shift at a higher rpm or just firm up the shift? I'm wondering if I should put it back in.
 
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Does sound like a TPS or MAF issue...for the shifting problem

and the shot motor mount will cause poor throttle response because when you hit the gas, the motor moves.. the car does not.

my motor mount broke and it caused all kinds of goofy crap like that to occur.
 
So a motor mount will make it seem like it's reving higher at take off when in fact it's just that the engine is tilting with the torque? The throttle response is good when in park but when in gear it seems mushy. I know the TC is suppose to slip some when engaging, it just seems that it is always slipping when applying the gas after coasting.

Would the engine tilting cause the TPS to mess up?

What would the MAF have to do with the shifting?
 
A vibration in "park" after a tranny rebuild could also be an improperly installed flex plate. This would be your installer's fault. This happened to me on tranny #2...bad vibration at around 1100 rpms...goes away at lower or higher rpms.

But switch those mounts out first and get back to us.
 
Sounds like an engine mount AND a bad TPS. We told you how to check it, so go check it! :D
 
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