Hey guys I purchased a 91 z28 this week and I am not against searching the forum from top to bottom but a little direction would be extremely helpful. When I hit higher rpms the car bogs and breaks up. The car was originally a 5.7 auto and has been swapped to a T5 of unknown origin. If Amy info is available I would forever be in debt to you guys. Thanks

 

Have you checked engine codes?

Is there hissing behind your dash?

 

I can't check engine codes because someone in the past decided to cut out the port. So I really don't have a lot to go off of unfortunately :-(

 

Ok, so i dug around underneath the dash and i found the diag. port. I have 3 codes coming up which are 15, 24, 42.

 

You should start with the code 15 for your 1227730 ecm sounds like a it might be a bad ecm.

http://chevythunder.com/Flow%20chart%20index.htm

 

thanks for the list i appreciate it, the car came with an extra computer so ill give it a shot and report back.

 

make sure you swap over the memcal it should be a anjf or aujp.

 

is that the memory looking chip in the ecu?

 

It is the engine /transmission calibration in the ecm under the long cover that is held on with 2 7mm screws

 

The ecu has a fast chip installed. My question is now if the car has a auto transmission chip and the car is a manual what do I need to do? I tried the other computer with that chip in it because thats all I have. And right now for the car to run decently I have the temp sensor under the throttle body unplugged and the ETC cable has been spliced with spade connectors And I leave it unplugged or else the car runs like it has a huge cam and then dies out at idle

 

Is the Ed wright fast chip on a adapter board ? Here is the specifications on the cts. A new cts is verry cheap. I would work on getting the code 15 taken care of and then if the car bucks any while slowing down or keeps running rich have the memcal reprogramed. You can send me a pm if you like to on programing.

 

yes the chip is on an adapter board. i tried my other ecm that came with the car with the same results. And by cts do you mean coolant temp sensor?

 

you can remove the piggyback fast chip and try just the memcal But I think there is a cts issue or a wiring issue. Yes I mean coolant temperature sensor gm 15326386

 

i will pick one up tomorrow! Thanks for helping a guy out, i really appreciate everything.

 

ok so i replaced the cts and the car seems to be doing better, but i went to check my engine codes and still have the same 3. ive searched on the forum and cant find a method to reset the codes to see if in fact i have fixed the DTC 15.

 

Disconnect your battery for 10 minutes or so.

 

Use the automatic chip. It is set up for the 22lbs injectors that in your car stock. The manual chip is for the 305 engine with 19lbs injectors.