The car was TBI, and I swapped to TPI. The motor was not rebuilt, and had about 95k miles on it. I don't think this problem has to do with the swap, I think it is a problem with something related to the motor.

Ok so I got the 305 TPI motor swapped in, and it ran good for a few weeks. Then it let me sit. The motor seems to have a problem now that was intermittent(randomly wouldn't start), but is now consistent. It will sit and idle, but depending on how hot the motor is, it will either not come off idle(stall if you try) or you can get it to go to 2500rpm(any higher and it will stall out). We thought it might be a clogged fuel filter, but we put a pressure gauge on it, and fuel pressure doesn't drop below 38lbs, and sits at 42 at idle. Tested the throttle position sensor, but it seems to be fine.

Any ideas?

1990 Formula 5-spd TPI.

Thanks,
Gary

 

Bump. Not a plugged cat btw.

 

air filter, cap rooter, plugs. Maybe a stall converter? ....you might have clogged injectors

 

It's a 5 speed Have you checked the ignition module?

 

Haven't checked the ignition module, but it's about next on my list. Any other ideas? I'm just looking to make a list of things to check.

-Gary

 

MAF setup?

 

It's a speed density motor and computer.

Update: Checked fuel pressure, and it's holding above 36 psi all the time. Repalced fuel filter just to be sure. Fuel pump runs, and the car will idle, but will die as soon as it hits 2700 or so RPM. If we supply fuel through the intake, it will continue past 2700, and will run just fine up much higher, so it's a fuel issue. It looks like the pump is holding pressure, so I am thinking the computer is not giving the car enough fuel. We tested the TPS, and it is at .54 volts and is smooth throughout it's area of operation. We've tried 2 different computers, with both acting exactly the same way. We tested the MAP sensor, and it acts as it should when vacuum is applied. I'm really stumped, because the car ran for 2 weeks on the road before we hit this problem.

Any ideas?