2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

3800rpm hesitation ?

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Old Mar 17, 2011 | 03:24 PM
  #1  
egplease's Avatar
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3800rpm hesitation ?

im 99 percent sure that i have it... its horrible...unbareable. but?

ive been looking into it and i just have one simple question?

I cant get to the ecu ground, i can barely see it but its rusted and nasty. im really really really do not want to take off the top intake for fear of messing it all up ( first rotory) so as far as additional grounds go what can i do and if i add a new one will the old one still muck it up?

also my clock tends to reset itself everytime i turn off the car? could this be from the bad ground aswell?

thanks guys and please dont flame me :S
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Old Mar 17, 2011 | 03:39 PM
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collink's Avatar
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From: Madison, AL
Originally Posted by egplease
im 99 percent sure that i have it... its horrible...unbareable. but?

ive been looking into it and i just have one simple question?

I cant get to the ecu ground, i can barely see it but its rusted and nasty. im really really really do not want to take off the top intake for fear of messing it all up ( first rotory) so as far as additional grounds go what can i do and if i add a new one will the old one still muck it up?

also my clock tends to reset itself everytime i turn off the car? could this be from the bad ground aswell?

thanks guys and please dont flame me :S
The clock issue sounds more like a bad constant. I can't see the ground being good while the car is running, but bad when it's off...

As far as the hesitation, I don't know enough about it to help. I had a buddy who had a really bad issue with it in his S4, and the solution for HIM was grounding the **** out of the engine. I would think that the bad ground would create an iffy at best connection (I mean let's face it, the engine IS grounded to the body in several places, but it'd be a worse connection). What he did was get some larger gauge wire and connect several points on the engine (I think they were near sensors) to points on the body.

YMMV.
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Old Mar 17, 2011 | 08:58 PM
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The clocks never work. Bad solder joints on the warning light/clock circuit board. This is in the FAQ.

The most effective approach I've seen to correcting 3800 RPM hesitation (also in the FAQ) is to splice into the ECU grounds at the ECU. There are 3 or 4 of them. Check the FSM fuel and emissions section for ECU pin outs, and the wiring diagrams to confirm wire colors before you cut anything. Testing the wires with a multimeter would also be a good idea so you don't get it wrong and short out the ECU.
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Old Apr 3, 2011 | 10:10 AM
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egplease's Avatar
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so just an update. i had a problem with my exhaust...the aftermarket header didnt meet the cat right and the gases burned the o2 wires all to hell... with that sorted out the car hesitated like twice and now seems fine ( minus the starting problem)

anyone had simliar result, do you think my grounds may be ok?
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Old Apr 3, 2011 | 11:09 AM
  #5  
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From: indianapolis
have you added a ground to your pressure sensor ? that might help . also replace the o2 sensor
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Old Apr 3, 2011 | 11:23 AM
  #6  
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There are 3 main grounds in the engine bay, correct me if I'm wrong.
Biggest one is bolted to the end of the longest starter bolt. Second one, hard to get to, sits under the manifold bolted at the top of the rear rotor housing. The third, a bit flimsy in my opinion, sits bolted to the edge of transmission housing (where the engine meets the trans on the passenger side). What they all have in common is that the wire jackets tend to harden up and crack under the temperature fluctuations and age. Because of that you may see the coper wire exposed and or corroded with green deposit.
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