OK, I just picked up a 95z34 for my stepdaughter and i managed to get a freak of course. It's still has an ODB1 computer and the connector doesn't have a test lead so I can't short the terminals and a cheap code reader won't do it either because I bought one and all it does is short the test lead anyway so basically it was a waste of $20. The car runs great up to about 4000rpm and then it's like it's hitting the rev limiter, I mean it'll actually smoke the front tire from a standing stop but at 4k it's just like the rev limiter in a race engine. I know these cars have a limiter set around that rpm but it's only supposed to function in park or neutral, not in gear. I do have a service engine light on but I can't pull the codes because this odb1 connector doesn't have the test lead in it, which I've heard some 94 and 95 models don't and I even broke down and called the local chevy dealer and they said they don't even have an odb1 scanner anymore??? I'm hoping maybe somebody has run into this problem with the rev limiter before maybe...

I have pulled all the plugs and they all look great, all good color and no signs of oil or anything that would indicate a misfire and there's no miss noticeable and no smoke out the exhaust so I really don't think it's any type of ignition or fuel delivery issue. Everything I'm seeing points to it hitting the rev limiter in my opinion...Does anyone have any ideas on what to look for or how to disable the rev limiter completely? It's not like my stepdaughter will be doing neutral drops or anything stupid but I want her to be able to pass a car on the highway safely and that's not possible now. I realize it's a $900 car with 212k miles on it so I don't expect perfection but this just isn't acceptable. I should have found it on my test drive but it ran so well around town I never thought to try running it up into high rpms...it runs like a champ right up to that 4k cut off...somebody throw me some ideas please...I'm stumped and a little frustrated at this point

 

Clogged cat converter. I just got a 98 z34 and it had identical symptoms. I bought the 2.5 inch downpipe with 400 cell cat converter from zzp. Fixed it right up. Now its like having a sleeper lol.

Was slightly more than a decent universal cat (w/ labor to install) and way easier to install so i did it myself... 4 bolts, just need a bunch of extensions lol. Its this one. https://zzperformance.com/3800/zzp-downpipe.html

Hope this maybe helps.

 

Unfortunately Jeff I have that oddball...I have learned that some of the 94-95 cars that still got the ODB1 computers but they elimated the test terminal in some of those cars I guess. I have the ground but the test terminal should be directly next to it and it's an empty hole...I was all set with my jumper wire and then there was no place to jumper too...lol. Even a cheao code reader won't work because I wasted the $20 to try it, apparently I need someone with a high dollar snap on style scanner to be .able to pull codes and clear them. Even my local dealer doesn't have one anymore...but I appreciate your help just the same! I just have to pick the oddest of the oddballs in everything...just ask my wife, she's was odd enough to say yes to me...lmao

 

Yea I used maybe 15 extensions when I did it.. Couldnt get them to stay straight enough so I decided to weld them together to make a sort of "super extender". Turns out I welded it at an angle that couldnt reach the rear manifold bolts.. 60 dollars in extensions down the drain..