TBKZ

I have a couple of problems with my 87 5.0 GT.When it idles it sometimes surges up and down and will finally cut off.Second problem is more serious.I'll be driving down the road and it will buck once or twice then cut off.Sometimes it will start right back up,but most of the time it takes 4 or 5 trys cranking on it before it will restart.Usually happens after driving for a while or after making 2 or 3 short trips.Any ideas on what it could be?I just replaced plugs,wires,cap,roter,gas filter,air filter.Thanks for your help.

spike306

clean the throttle body assembly and that should take care of your surging up down. your other prob. is possibly a fuel pump.

83stang

i have the same problem but i dont think its the pump because those are electric and when they go they uselly go ao if any one has an idea that would be great.

converted

I think it is your IAB. Or did you just do any major mods to your car?

spike306

you might wanna take apart your distributor. a few things in there would make it act like you discribed. forinstence, the pick-up wire. chek that first.

302forever

Does it have the ignition module on the side of the distributor? That was a major boo boo by the engineers! Transistors don't like temperatures over about 200F. The module may be breaking down when the dist. gets hot. Those modules need to be moved over onto a fender. If you don't run down a problem elsewhere you might try a new module. If that seems to fix it I'd patch the hole in the side of the dist. and move the module to a cooler location. I've done it and the modules pretty much live forever.

Black92LX

Both Spike306 and 302forever have good points. The location for the ignition module on 5.0's suck. It's just held on by two 7/32 screws, pull it and take it to your local autozone and they'll test it for ya, it might take a couple tests to get it hot enough to fail. While you're tearing into the distributor, remove the rotor and rotating assembly and check your pickup and stator for heat stress, loose wires, etc.....My pick up was laying in three pieces in the bottom of my distributor. Let us know what you find out.

90MustangGt25

any surging idle at cold start up can be caused by a coolant temp sonsor! Thats one of the first sensors the car reads off of. Ur bucking problem could be caused by something else.. Mine would rev and rev and then stall... replaced coolant temp sensor and start up is much better.. not necesiarly the problem but its like $20 bucks and real easy...

302forever

We didn't know how good we had when we had carbs. on everything. That's just one more thing the engineers screwed up. Computers and engines need to keep their distance from each other!