CreepingDeath94

iTrader: (4)

I also posted on the engine swap section. I have an '89 Trans-Am and recently rebuilt the motor as the previos one had a spun front main bearing. Upon pulling it out, I found it was a 305. Since the main was spun, I opted to get a 350 4 bolt block but kept my 305 heads as they were H.O. heads. This raised the compression however I used dished pistons to try and limit the amount the compression went up. The engine was bored .030 over as well. In addition, I used a stock spec. 350 roller cam, used the 350 knock sensor, ESC module, etc. Basically, any components that were 305/350 specific I replaced with the 350 components. I also had the PROM reprogrammed for the 19lb. injectors that were on the 305 intake, dumped the EGR, VATS, and cold start set-up that was on this intake. I did the elimination in the PROM as well when I sent it out for reprogram. I think thats everything as far as the engine and any mods.

Alright, heres my question. What am I missing? The engine still doesnt run properly. It takes forever to get her fired cold and a little less but still way too long once its warm. Basically, it takes forever to start while I have to feather and monkey with the pedal until it finally does start, but barely runs til it warms for a minute. Then it idles rough and seems slightly hesitatant on the throttle response. It is timed to the stock 6 degrees. It seems to me like the timing is off. Could it be that I need to adjust the timing to something other than stock settings due to the various interchanged parts and compression? Should I retard it to 4 degrees? 2? Im at a loss here. Any help would be greatly appreciated.

Red Devil

Well, first thing is neither '89 TPI (305, 350) had any cold start stuff on the intake, it was all in the chip. Next would be the question of cades, are there any? Have you been able to datalog it? Have you verified if you are going into closed loop?
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Oh yea, and did you have those injectors gone over at all? Have you tried a stock 350 chip too?

CreepingDeath94

iTrader: (4)

I know the '89 never had the cold start, but I guess the 305 that was put in there was out of an '88. Sicne the PROM was stock '89 350, the cold start probably didnt need to be eliminated...just put it on the list for them just in case. As far as codes, it was popping the light on before I had the PROM reprogrammed, so either the light was for EGR or something, or the problem isn't happening anymore. I haven't had a chance to drive it or even get any miles on it even to the shop as I started redoing the rusted out brake lines and ran into a problem when I found the rear brake line from ther master cylinder to the rear brake tee off was a metric bubble flare larger than anything they fricking make at parts stores. So ive been fighting that and finally found someone to make me some lines bubble flared for the thing. Once thats taken care of, I wanted it to be running correctly so I dont mess up the new motor driving it if were too lean or something.

To answer your questions, I don't know if its going into closed loop nor have I had a chance to get her hooked up to a scan tool. Basically, if its not something simple that im just overlooking that I can do at the house, ill be bringing it to my mechanic to hook up the scan tool and deal with the timing. I just was looking for things I may have missed or overlooked.