Hey

I have an 88 s10 with a 305tpi/auto out of an 87 Camaro. The stock computer and harness is used, just spliced into the factory s10 wiring inside. I bought the truck with the swap already done but once I brought it home I noticed some of the wiring was badly butchered, for example the fuel pump was getting its power directly from the distributor ignition lead with the ops bypassed.

I unwrapped the complete harness and traced everything back to the ECM (which is brand new from the install) and fixed all the issues back to stock Camaro form, which I'm not sure why it wasn't done before as it was straight forward with a stock wiring diagram. At the same time I cleaned up the intake, runners, tb, and put a new gasket kit into it. The egr and MAF are also new

I got it all back together today and fired it up. I had a feeling the timing was way off as it had very hard cranking issues before and found that base timing was off the timing plate 12, 16 degrees? advanced heh... And brought that back to zero and adjusted tps. Now my hard start problems are gone and idle is smooth for as long as it does.

Now to my issue, the truck will idle at operating temp for about 30 sec just fine but then the idle will jump maybe 100-200 rpm on its own for about 2-5 secs and come back down and stall out, almost like a wandering idle that can't compensate once it comes back down. Also when I put the the truck into gear it will stall unless I give it throttle.

Some other info about the motor. Stock displacement and cam, 1.6 comp rollers, new distributor cap, rotor, module, coil not sure, 8.8mm msd wires, headers, tb airfoil ( the airflow inducer thing )...

Sorry for the lengthy post but wanted to get as much info out as I can. I'm not a rooking to mechanics or to Camaros as I've had a few of them before but just not too familiar with the tpi stuff. Would a bad iac cause something like this? It rattled while I was adjusted the tps until I unplugged it... Or I have a slightly worn throttle shaft the moves back and forth a few thous causing a .02 or so change in the tps voltage...

Not sure what else to look at. Appreciate any help or thoughts, or questions

Art

 

I think I might have solved the problem after some more bad relay wiring that I missed.