not a mustang but same concept, runs like crap!
 

had a guy swap motors from a 85 bronco to a 86 P.U. Both had 302 EFI's. The P.U. had a bad motor.

He comleted the swap and called me. i took the truck home tonite. it seemed to run good untill it warmed up (5 miles down the road), then it lost alot of power (top speed 65 mph).. while driving at 50, it keeps kicking out of top gear when you let off the gas. Also, any short test drive (of a mile or two) and the exhaust manifold's get so hot they get red...

Both vehicles ran good prior to the engine swap (other than bad main bearing in the truck motor).

I really need to drive this truck until the weather improves...


HELP PLEEZ!!!

You're running SUPER lean or you have some major timing issues. What kind of injection systems are you working with? CFI, SEFI?

Did he swap the ECM too?

I don't think he swapped the ECM..


CFI or SEFI?? I don't understand...



My head hurts...

The truck had an MFI (Multi-point Fuel Injection) system. The Bronco may have had a CFI (Central Fuel Injection) system. Did both intakes look the same? Either way, the ECM needs to be swapped.

Take care,
-Chris

yes, the intakes looked the same...


I'll ask him if he changed it...



Thanx for the help..

just thinking about this problem,

could'nt it be a vacuum leak somewhere????

dose it still have the cats ????

Yes, both cats.. You thinking plugged??

Just sprayed carb cleaner all over the motor looking for a vacuum leak, no change in RPM's, so I am guessing no leaks...

Do fords have a vacuum line going to their auto trans????


Then again, I 'paid' this guy to swap motors, why am i even messing with it???


To answer myself, I'm a glutton for punishment??



Chris

where would the ECM be??

Should be behind the drivers side kick panel.

Take care,
-Chris

Sounds like you need to swap the computer. Also, maybe you skipped a tooth on the distributor swap.

if it pluged the exhaust wont breath just put your hand over the tail pipe to see if theres any pressure

I have a hard time understanding how you could even hook up a CFI engine to an SEFI harness. As far as the cats being clogged, it wouldn't have run great for 5min. Sounds to me like it might be an emissions system deal too.

Good luck with the computer.

Just a thought when I had my firebird I made it probably 20 miles before it shut down and with out the exhaust breathing it turned my pipes cherry red, and then it slowed to a idle for a few then died....

When I put my 302 back togather i skept one tooth on the disturber gear . I got a false timing on the car . It would run ok for a little while then the headers would get cherry red. Then the car would stop running. Sorry about the spelling.