I have an 89 L98 with slight mods. I had a chip made to put in the ecm to delete VATS, EGR, and AIR pump. It has a painless wire harness, is a v6 swap car. anyway, the car turns on and runs, I can drive it around, whatever. But sometimes, the ses light just flickers on and off, the cars rpms start to move sparatically like it isn't getting fuel, then the problem stops and the car runs fine again. sometimes when it does this the car shuts down if I don't put my foot into the gass pedal. when I jumper the ALDL I get a code 51, rarely do i get code 42. 51= prom error 42=Electronic spark module issue. What I have read is sometimes code 51 will cause a false code 42 to show up. (I put in a new spark module when I swapped engines 2 months ago) so, what I am asking is does this mean my PROM is bad?

Thanks!
Jonny B

P.S. the error codes only show up when the car dies not when I shut it off after it has started running fine again.

 

Hey
Did you figure out your problem?
my car is doing the same thing

 

nope... still having same issue...

 

Same problem here. Exactly the same. Did you fix the problem?

 

Yes I did
It was my moates auto prom, I burnt a chip and unhooked my auto prom and the car runs perfect, so now I don't do real time tuning

 

How much did it cost to burn a new PROM? I believe that my Hypertech 127062 PORM is that problem because I keep getting code 51 on two seperate ECM's.

 

It didn't cost me anything because I have the tools to do it myself, I think you need to check the connection between your piggy back, chip and ecm, make sure they are tight and not loose (I bent all the little tangs on the ecm that plug into the piggy back a little to the left so they fit tight), but be very careful doing something like that. Also check all your ecm grounds and that your connectors from the car to the ecm are tight and make a good connection.

 

Okay. Will do that later on today. But what do you mean up there in red? Chip as in PROM andECM as ECM, but what is the piggyback? Perhaps the whole PROM?

 

By the way, would you rent out your programmer?

 

I replaced my whole chip with a new one from ACDelco and it still does the same thing...

 

I'd have to check on this in the morning, as my FSM is in the garage, but I believe DTC 51 isn't necessarily a PROM error, as is stated around the Web. IIRC, DTC 51 means "Cylinder Select Error" and can be caused by a wire at the ECM that is in the wrong hole... This wire tells the ECM whether the engine is a 6 or 8-cylinder based on which hole it's in. As I said before, I'll check on this.

 

Well actually, I have been driving from and to work for about 2 months and bammm, The trouble began. It's intermittant. I turn off the Camaro, turn it back on and I get no SES. So Im confused.

 

Then the issue probably lies in either the ECM or the wiring harness. Lets wait and see what Maverick H1L comes up with.

 

I am hoping it is the ecm... I really don't wanna eff with the harness... again...

 

I agree man. Thats a crap load of wire to run, not to mention that it costs around $400 for a new one.

 

Maverick H1L, were you able to get that info from your FSM about the code 51?

 

I Didn't have time to wait (my car is my daily driver) Just threw money at the next logical cause of the problem and BOOM. Problem solved. Re-man ECM from Autozone. 77 bucks. She runs like a dream.

Jonny B.

 

Good for you bro. Im gonna do the same. It's time to save some money for a Reman ECM.

 

Well I never followed up on this post so I will give a extremely late update on my TC 51. The problem ended up being the Hypertech chip that I had. I sent the PROM to a fellow member here in the boards and he tried to extract the BIN file to make me a new EPROM. Well on his TunerPro, the BIN file was trashed. So this explained that the Hypertech 127062 PROM was bad. So I then contacted another member here on the boards and he was kind enough to burn me a chip with a 87 IROC BIN file for free. All I paid was the shipping and the cost of the EPROM. So as I installed my new burnt chip by using a Moates adapter, my IROC fired up and I never agian got a TC 51. Here is my burnt chip that fellow TGO member hooked me up with http://www.youtube.com/watch?v=qO5YZvWS8I8.