I have an 86 with the L98 motor. At higher RPM the motor really starts to chatter. I would say it starts at 4500 rpm and on. I thought it might be timing, but I am having trouble getting it right.
Might it be because I am using cheap gas? Are those early cars set up for 93 octane? It sounds like the top of the motor is floating for lack of a better word. I have ad have had LS1, LT1's and the likes none have this problem. Is it normal for L98 motors?
The car runs like it is in LIMP mode most of the time. I don't know whats up.
I have a 4-3 trans in my 86. Just after I had my clutch replaced. 1 week later, the o/d started to run in and out of gear. Up and down up and down. Then it stops all together. I reset the computer; it tried to shift a few times, same thing then it stops trying.
I can control the dash light with the button on the shifter, but trans dose not move.
I checked the relay on the firewall. No problem there.
I replaced the ECM. No fix there.

I will have it back on the lift on the shop today. Any ideas of what to look for? I have the haynes manual, not much in there about this trans. It is vague at best.

Flustered.
:nopity:

:ack2: also have a 86 convert,with 4+3 NEVER HAD THE CHATTER YOUR TALKING ABOUT UNLESS YOU MEAN PING FROM LOW OCTANE GAS I ALWAYS USE 93 ,NO PROBLEM, AND AS OVERDRIVE I HAVE NOT HAD THE PROBLEM ONLY PROBLEM WITH MINE AFTER WE PUT CLUTCH IN WAS BUTTON KEPT STICKING HAD TO ADJUST IT ,IT WOULD NOT POP BACK UP TOOK PART OF A SPRING OUT OF A PEN TOP SLID IT DOWN UNDER THE BUTTON IT WORKED :cheers:

Man, sorry to hear about your guys problems! Hope you get them taken care of ASAP and get back to having fun with them!!:thumbsup3:

I always run at least 91 in my 85. It pings really hard on the cheap stuff. As for the transmission thing, did you loose any fluid during the clutch change. I dont know much about the doug nash deal... :burnout:

We replaced the fluid, we replaced it all. I think it is something electrical. I unplugged the kick down connection on the side of the trans last night it still did not shift correctly. This thing has me pulling my hair out. I really just want to bypass the switch all together and make the O/D shift manual.
Has anyone heard of how to do that... anyone have that book called 101 things you can do to your C4 corvette.

Mechanic thinks the chatter might be lifters, because of the spark advance not advancing the timing... SEE why I am not a mechanic... This sucks!!

Allways use the good stuff in mine,but thats my baby got a 88!

Mechanic thinks the chatter might be lifters, because of the spark advance not advancing the timing... SEE why I am not a mechanic... This sucks!!

holy crap I'm doing everthing wrong run 10 degrees over top dead center & yup I can turn a wrench!!

We replaced the fluid, we replaced it all. I think it is something electrical. I unplugged the kick down connection on the side of the trans last night it still did not shift correctly. This thing has me pulling my hair out. I really just want to bypass the switch all together and make the O/D shift manual.
Has anyone heard of how to do that... anyone have that book called 101 things you can do to your C4 corvette.

Nope!!

holy crap I'm doing everthing wrong run 10 degrees over top dead center & yup I can turn a wrench!!

??? SARCASIM? I didn't get it. someone out there must have had the problems I am describing.

??? SARCASIM? I didn't get it. someone out there must have had the problems I am describing.

No harm intended???

We replaced the fluid, we replaced it all. I think it is something electrical. I unplugged the kick down connection on the side of the trans last night it still did not shift correctly. This thing has me pulling my hair out. I really just want to bypass the switch all together and make the O/D shift manual.
Has anyone heard of how to do that... anyone have that book called 101 things you can do to your C4 corvette.:ack2: you can put in a rocker switch on the console and disconnect the button on the shifter ,thus engaging it manually thru the switch ,,my mech, said he can do it and i am going to get it done before i put it in storage next month:banana:

:ack2: you can put in a rocker switch on the console and disconnect the button on the shifter ,thus engaging it manually thru the switch ,,my mech, said he can do it and i am going to get it done before i put it in storage next month:banana:
That is what I want to do. a switch to make it manual. It is in the shop now, hope they can figure that much out.

No harm intended???

no worries, I am the king of sarcasm, I just didn't know if you were kidding or serious... I just want this stupid car to run great for 1 day. I would be happy then.

I know when my babys not feeling good I get pissed!! got a coupe also!!

I fixed the chatter, 93 octane gas, and the trans was working for like 15 miles... hey, its a start. The shop adjusted the shifter contacts? In the button itself. They will do it agian, that does seem to be the problem. In going to the shop they say I now need a new MAF, and EGR.

More money, more money.

:thumbsup3:

Thats all it takes is money! money! money!

: That is what I want to do. a switch to make it manual. It is in the shop now, hope they can figure that much out.:thumbsup3: did mine myself yesterday just removed the switch from the shifter drilled a hole in the center console next to the power seat switches ,now it works perfect,very easy fix:cheers:

Has anybody bothered to check the knock sensor in the block?

Man, sorry to hear about your guys problems! Hope you get them taken care of ASAP and get back to having fun with them!!:thumbsup3:here here!! good luck!

It is so far so good, I guess the clutch they put in was slipping so the rear unit went into "safe mode"? oh well its working now... yea!!