Pulled a 305 TBI out of a 89 transam and put in my truck for fuel
injection. Ran fine for awhile, but playing in the mud took it's toll.
Had to rebuild engine. Put back in and now it won't idle in gear at
600-650 like it should. Idled fine before but now will idle for a
minute then like something kicks on and it almost dies(sometimes
stalls) and goes up to about 1000 rpms before trying it all over
again. If its warm and you let it idle while trying to put it in gear
it's 90 percent chance of a stall. If its cold it's fine but the rpms
are above 1000. Looking for any suggestions as I'm stumped and the
dealership is of no use(see below).
What's been done:
Rebuilt engine, new rings, rod and main bearings, crankshaft, cam
bearings, gaskets, timing set, and oil pump. Reused roller cam and
lifters. Heads rebuilt. New plugs, plug wires, rotor and cap. New idle
control actuator, throttle position sensor, coolant temp. sensor, oil
pressure sensor, pcv valve, air filter, egr plugged and disconnected.
No codes registered by computer.
Tried swapping top half of throttle bodies with a spare I have - no
Tried swapping new ignition module - no effect.
Done compression check. After 3 turns all cylinders hit at least 90
psi. After 5 turns all cylinders where at maxium of 150 psi. So I
believe that is fine.
Oil pressure is about 65 psi when idle and cold. After warm-up comes
down to around 45 psi.
Ran out of ideas so took to dealership to let them try. Then claim it
had a weak magnet on the distributor shaft and the pick-up coil was
weak. So I brought it back home and swaped out the spare distributor I
had and still no effect. Called them back and they said it HAS to be a
new distributor to fix the problem. I'm not above buying a new one but
about half the money I spent on this thing was trying to fix this
stupid idle problem. So I want to make sure that will fix it before I
spend the money. That and I don't think it would be just a problem at
idle if it was the problem. It has great power(it's a 305) and runs
fine as long as it's not around 600-700 rpms where it wants to start
floating around and then stall. Right now I drive with both feet
keeping it about 800 rpms when in gear and it's fine.
A/C is not hooked up and the 700r4 trans behind it was fine before the
rebuild. The valves rattle when under load so I'm going to recheck the
valve lash this weekend. Timing is at zero with computer disconnected.
Although I don't think it would cause the idle problem would it?
Any help or suggestions would be welcome. TIA!