1998 Mustang GT 4.6 69,000 miles...

[tuned]

Just bought it recently, and have stumbled across a problem. At around 45-50 mph when the RPM's are at around 1 and a half the car acts as if its going to stall out. It likes hops around and like shakes sort of. But if i just get on the gas alot it will jet and be fine but just at that point it does that. Keep in mind its automatic. When its idleing every so often like every 10-20 secs it like hops like its about to stall. I don't know what the hell is wrong with it really. I don't know much about cars at all so any help and or suggestions would be good, thanks.

tuned

 

[tuned]

no one knows or am i in the wrong forum or what?

 

[krly79]

Try cleaning your IAC valve. It kinda sounds like it cycling. It could just be all crudy. Try and clean it and then if that makes it better, go buy a new one. They aren't that expensive.

 

[Brisk281GT]

Replace or clean your IAC. I had a similar problem. You can try cleaning it with carb-cleaner or get a new one for $50 at Autozone. It's probably the problem.

 

[krly79]

I'm trying to post a pic of what you need to pull of and change, but cardomain sucks.

 

[Turbo92PGT]

Get some new plugs and wires, fuel filter and everything. Hopefully that'll work for ya.

 

[nyuk98gt]

tuned:

It is the torque converter locking and unlocking and it can be annoying. It can be made worse (more noticeable) by old/dirty ATF. So, changing the ATF and filter may help. If you have the cash, you can get a chip or reflash of the PCM to fix it.

 

[joestang98]

sorry to jump topics but nyuk98gt...do you know your RWHP?? I have pretty much the same setup but have LT's and Dr. Gas O/R -X also accufab TB/Plenum combo. Just wanted to know what I might be putting down. THANKS!

 

[nyuk98gt]

joestang98:

Well, before the PI intake and Comp cams, she put down 194.6 rwhp and 261.7 rwtq. I'm still working on a few tuning gremlins now before I get to the dyno again.

I would guess that your mods will add about 15 rwhp over mine (mainly due to the LT's).

Chris