Hey everyone....

This is a first for my TA. Its an 86 305 TPI with a 700R4. This just started happening last night and today while i was in NJ for the holiday. Going anywhere from 55-70mph continuously, and if i let off the gas, and then get back on it slowly, my service engine soon light flickers once(really quickly), and the car bogs for a split second, and then everything seems to be normal. This all happens very fast, and the engine light doesnt stay on. It happend several times last night, and a few times today as I was headed back to PA, but for the last 20 or so miles of my trip, it did not happen. What the heck could cause this? I used the "paper clip method" to see if i could pull any codes, but all i got was the 12. The most recent major repair i have done to the car was a new(rebuilt) ECM. I used the orginal prom, and that was about 4 months ago....the car ran awesome after i changed that, and no problems. Any clues? Thanks for your help.

 

Alot of f-bodies experience this problem close to the 70mph mark. For whatever reason the EGR trips a code. My car does it and apparently it is known to most people. Usually it throws an EGR code. I changed my EGR and it still did it. I just cruise at a little faster or slower. I think theres an article in the TECH section

 

Thanks for the reply. However, I dont think this is normal, because I had an EGR code about a year ago, and i changed it also...since then, no code, and no EGR symptoms have come back. This has just started to happen sunday for the first time ever. And cruising a bit faster or slower doesnt help, since this problem occurs anywhere between 55-70 mph as i said in my first post. Anyone else have any other ideas?

 

Anyone???

 

Wild guess...

It would seem like your throttle position sensor could be a culprit. In a Chrysler turbo I had, the section of the rheostat (or ?) on the sensor that had constant wear started to act up (at or around steady throttle positions like you are describing).

I honestly don't remember if it brought up codes right away or not. Do you have a spare one to swap it out with?

 

Thanks for the quick response. I acutally dont have a spare to swap it back out with. I remember changing it about 3 years back...and someone else who is good with 3rd gen's(he used to have an IROC)said the same thing....so maybe i'll change it and see what happens. I just hope its something inexpensive like that. She's got 135k on her...just want her to run good till the motor goes and i can swap in something wicked

 

Is the EGR passage blocked up? Many times the airway gets large carbon deposits and effectively gets clogged or pieces prevent the valve from completely closing. How is the vacuum line to it. My 89 uses a solenoid and it got sticky causing something similiar.

 

As far as i am concerned, everything looks good to the EGR. Seems fine to me there.