1989 Ford Mustang Runs great for about 4 blocks then starts

READMAGIC

MEMBER
1989 FORD MUSTANG
V8
2WD
AUTOMATIC
72,000 MILES

When you first start this car when it is COLD, you can count on this car to run great, hit passing gear and shift great for about 4 blocks and then it starts popping and won't have any power at all. If you try to give it gas it will fall flat on it's face. Your can't get over 1o to 15 mph. You can shut it down and wait about 4 hrs and it happens exactly like it did before when it was cold. We have replaced everthing from the air filter to the throtle body, replaced the spark plugs, plug wires, distributor cap and rotor. At idle you can hear the fuel pump in the tank performing like it should. While ideling, you can try to rev the engine up and it will start popping and start falling on it's face. Any Ideas?

2 Replies

MUSTANG87

MECHANIC
261 POSTS

Man hard to say without looking at it but did u change fuel filter?I would check for a bad catalic converter wich midas or any other mufler shop can check sometimes for free. Sometimes fuel pumps work fine when cold then they get over heated and fail. Check the air line that goes to map sensor. Not sure if 89 has airline there but 87 does my, car. If it does it should run from map sensor and conects to back of top air intake where the 5.0 sighn is thats top. If it does have vac hose, feel it if its to soft and chewylike. Touch it farthest u can and if its bad change it u have to remove intake but its easy. My car had a problem like that and it was that hose that was bad. But not sure if 89 has it. Check all air hoses that go to throtle body for cracks miising etc. Oxigen sensors too may be bad. Hard to say with out looking at car but im good with those cars its my best car and have always driven those only. Well wish u good luck