Losing power as it warms up. Changed cap and rotor. Had ignition module checked and regreased when reinstalling. Changed fuel pump assembly 2 years ago. Car sat for 10 years. Only needed fuel pump to get running. Has run fine until lately. Plugs look good. New fuel and air filters. Exhaust seems ok. Checked temp of cat when running bad. Front around 250. Middle 400. Rear pipe out 180. Had to keep idle above 2000 to keep running. Also rebuilt fuel pressure regulator at TBI. Set code for ESC. Checked timing and is advancing but erratic. Unplugged ESC timing was better but still jumping. Ran car with disconnected ESC but still started to lose power as warmed up. Car has 58000 miles.

 

Sounds like a plugged cat

 

Check fuel pressure & see if the ign. timing advances when you rev it. Make sure base ign. timing is correct.

 

Try cleaning your egr if it is hanging up it would give you problems like a vac leak.

 

Checked fuel pressure at filter. only place I could hook up adapter 14psi steady. check and cleaned egr working all right. checked timing and seems to be set correct but was jumping around even at idle. advanced with rpm's but still erratic. seems to be jumping around 8-10 degrees just staying at idle and at advanced rpm's. does this sound like an ignition module or distributor problem? I can't seem to figure out how the timing advances on this set-up. with no movement or the rotor possible I can't seems to get my head around it. rotor position and cap position never can change. is it possible the coil can be bad. need to find a way to check.

 

14 PSI on a tuned port car is way too low.


when you say "losing power" what exactly do you mean?

runs and dies ??? or losing electrical power and dies... ?

since you did not mention anything about the battery & alternator I assume you have NOT tested the charging system yet.


any good repair manual will show you how to test the ignition coil, but if the car sat for 10 years you should really be checking the battery & alternator.

A tuned port car will have a shrader valve on the fuel rail to test fuel pressure.

 

Car has the 305 with TBI injection Manual tranny. I am calling loosing power the fact that it won't accelerate hardly at all. Won't idle. Had to keep rpm's about 2000 and use right gears just to get it home last time I drove it. Started having this problem just the last few weeks. Ran fine before that. Has a new battery and alternator is putting out 14.5 volts. After driving about 15 miles it starts acting up with no top end power. Won't hold speed at 65 at that point. I drive 25 miles to work and that is when I started noticing the troubles. Also changed the thermostat because the motor wasn't coming up to temp.

 

14 psi is fine for TBI fuel pressure.. did you test the pressure under load? to rule out weak pump or clogged lines?

otherwise it sounds like a spark / timing / ignition issue..

any trouble codes? to rule out sensors?

 

Still having same troubles. Changed to new distributor, coil, catalytic converter, drained gas and put in fresh. Runs ok when started cold then gets worst when warming up. Cat was bad, had above 5 psi back pressure under load. Checked erg and it was clean and opened ok. Also changed the temp sensor for motor. Can an ECM be checked out? It was not getting warm to touch when acting up.