unprdictable1

iTrader: (2)

Hey everyone, I'm new to the forum, although I have been lurking around here for a month or so. You guy/gals have some great knowledge & usefull hints & tips on these awesome 3rd Gen classics. A little about me, I have been a mechanic most of my life. 3 yrs ago my back gave out on me and I stopped turning wrenches full time for a living. I am now a service manager for a well known automotive service center. Anyways, I just recently bought a 85 Camaro Z28 that someone did a swap in. They lied to me about the mods done, I found out later after I bought the car (thats another story in itself) What I've got is a 86-88 350 block from a truck, (seems like there is a cam in it) 85 305 HO heads, and the 85 Camaro TPI set up on top with a 700R4 trans. I have replaced the ECM, prom, calpak, distributor, ESC, MAF, IAT, & Knock Sensor all for a 85 Corvette (thanks to TPIparts.net for there help) The car starts up and runs really bad like it is searching for an Idle rpm. In the begining I had a code #33. The MAF Burn Module was not sending 12volts to the MAF. So I ran a jumper wire to the MAF and it seemed to do alot better, and now the MAF is working. It still has a really bad idle. I just ordered a MAF Burn Module in hopes of fixing the problem. The weird thing is when checking timing at idle it says it's at 55 degrees!! used 2 different guns to double check. It shouldn't be running at all with that kind of timing. Plus, when my scan tool is hooked up and reading the data stream the engine runs smooth, but disconnect it, and it runs like crap again??? Any suggestions?? Thanks

camaronewbie

I'm no expert here, especially with TPI. But I do know that the ESC module is going to advance/retard the timing as it sees fit based on knock and other factors. To get a base timing read, you have to disconnect the EST wire so that the ESC no longer has control of the timing.

Then, you have to consider what the ESC module and ECM is 'seeing' from the other sensors in order for it to advance the timing that far at an idle. Maybe there's an issue with the knock sensor (did anyone put in the 350 knock sensor instead of the 305 knock sensor?), etc.

Not much help - sorry.

unprdictable1

iTrader: (2)

Yes, all the sensors on the car have been changed over to the 5.7 350 sensors. I did have the wire for setting timing disconnected. I'm starting to think the previous owner installed a "to radical" cam in the engine. As well as when it was installed they didn't line up the cam and crank at "0" degrees. He probably thought he could set it advanced to get more power. So today, I'm gonna rotate the motor around to TDC on #1 cylider and then see where the timing mark lines up on the dampner. I'm also thinking that they may have put a 305 dampner on instead of the 350 which is why the timing looks so high. Either way I'll know weather or not I've got to pull the timing cover & reset the cam, or install a new one after today. Keeping my fingers crossed that it's a simple fix and that I don't have to spend all that time and extra cash to go into the motor.

unprdictable1

iTrader: (2)

WhoooooHooooooo!! Fianlly got the Camaro running right! The timing was all out of whack. The distributor was 180 degrees off, and the timing marks on the balancer were completely wrong. Got it set at 10 degrees, idles around 800rpms (a lil choppy cuz of the cam) put it in gear and it hold around 550-600rpms. Mash the throttle and she takes off with out a stumble. Shifts good too.