scottistang

I have a 1989 Mustang 5.0 LX and it runs fine when i first start it and drive it but when it warms up after its been running for a while it doesnt idle good and doesnt have nearly as much power. Anyone had this problem? I've read maybe i should clean my mass air flow and TPS but any info woudl be great thanks everyone

primetime5.0

have your tfi tested, its the module on the front of the distributor

kennebell92conv

i had the same backfire and found that my spark plugs was worn replace plugs
and now running good

ohfiveride

check to see if your distributor cap is cracked.....i had the same problem but it only did this when it was wet or humid out..turned out that when it is humid moisture got inside and wet the contact points....ran fine when it was dry out

scottistang

Yeah getting new plugs tomorrow, replaced the cap/rotor and wires last summer so i wouldnt think it would be that but id have to check it out. thanks guys

preciousroy

had the same problem on my 87, tfi module was bad, seems to be a very common problem, there like 50 bux from ford, cant hurt.

Vertastang

i had the same prob on my 88gt it was my fuel pump, would run awesome up till it got warmed up or hot out, changed it out and no more prob!!

00limited7

Some autoparts stores can do a bench test on the TFI module to see if it is bad. You'll need a special tool to take the TFI module off. It's a real thin walled socket/hand tool, I bought one at Advanced auto for less than 5 bucks I think.

Good Luck