acerulz

hey all, i took a 350 from an iroc and slid it into my 84 caddy fleetwood, the caddy has digital fuel injection and i made it work using a 350 tbi unit, blocked off the IAC and mounted the idle speed motor onto it. rewired the 350 "smaller type" distributor to run with the caddy electronics and all is well. i have no codes, when the engine is cold, it runs good. when it warms up, it has a slight rough idle, and with it in gear and foot on the brake it runs even more rough and sometimes stalls. fuel pressure was low, so changed the pump and filter but it didn't help it. everything is stock, except for an rv cam, and removed the air pump, but left the solenoids active. any ideas? if more info is needed, just ask.....i've done too much for this engine swap to list LOL

acerulz

k, changed the alternator and its not stalling anymore, voltage was dropping to 10-11 volts at idle. still have the warm rough running problem. could it be a coil, module or distributor shaft issue? had it on the otc scanner and all data seems to be perfect, o2 at idle seems to be switching a little lazy, but aside from that, all is ok. could the o2 cause such an issue? or if the valves are adjusted too tight? still has lots of power, more noticeable at idle and just off idle. just need something to go on before i have to start throwing money at it.

FNFAL308

iTrader: (1)

Could be too much overlap in your cam. Chip may need to be tuned.

Could be your TPS?

As I JUST typed in another thread. I have an 89 IROC 350 with an aftermarket cam and I also have a rough idle - but it is better now that I changed the TPS.

What cam do you have? What other mods?

acerulz

shouldn't need to burn the chip cuz i just put a mild rv cam into the build. tps is covered already, i kept the chevy tps and wasn't working out, so i put the adjustable caddy tps back into it. rough idle wouldn't really bother me, but it is an inconsistent idle. every once in a while it glitches. the downfall is that my tranny gave up last night, i lost all forward gears so i gotta pull it. but i was messing around and changed the ignition module and i t seems to run a bit better. could the idle be just the rv cam since it got better with another module? no major mods, just custom 2 1/2" no cat exhaust, 2" tbi spacer, k&n air, and the fact that its caddy electronics running a 350 chev haha. its all the same technology tho, so it should have no problem adjusting spark and fuel curves, correct?

FNFAL308

iTrader: (1)

I wouldn't think the caddy chip for an engine that is completely different would be the right way to go. It would be better to transplant the ecm for the 350.

But search on cam overlap and maybe go into the prom burning and electronics section, you have way too many far out variables in what you are doing.