93 Bucking Sometimes a small intake backfire

**coralcoupe1993** · 07-17-2014, 10:50 PM

I am getting some bucking under light/normal acceleration. Fine at idle, fine at WOT. Timing 14*, FP 39-40. TPS .99V. Valve preload fine (hyd cam) No apparent vac leaks. Trickflow heads, cam,intake, 70 mil TB, 76mil MAF and so on.

I built this car like 15 years ago. It has always ran perfect. Started doing this last fall before storage. So about 100 miles ago. lol I dont drive the car at but starting to now. Need it to run right. I have had a handful of these cars and always have them dialed in. Just want to see if anyone has had and solved this issue before I dig in further.

**John4cam** · 07-17-2014, 10:54 PM

Try cleaning the Maf.

**coralcoupe1993** · 07-17-2014, 11:07 PM

Thats something I havent done in a while. Good idea! Its funny, have put so many of these together.... never had an issue. Funny overtime even without much driving they get mad! Like a carbed car!

**mustang50lx** · 07-17-2014, 11:07 PM

Sounds like a bad spark plug wire or other ignition problem. Do have a way to get a scope on it?

**silvernotch** · 07-17-2014, 11:14 PM

we got some afm wires, and a 331 that doesnt buck, that will fix it.

**John4cam** · 07-17-2014, 11:45 PM

Originally Posted by coralcoupe1993

Thats something I havent done in a while. Good idea! Its funny, have put so many of these together.... never had an issue. Funny overtime even without much driving they get mad! Like a carbed car!

Yeah they're also getting old! Lol. Can get an antique plate for a lot of foxes already, crazy how time flies. I do know that a lot of tuners stay away from these cars due to wiring issues. I guess old harnesses ect. give them fits.

**White5.0** · 07-18-2014, 09:49 AM

This happened to me before and it ended up being a bad ground. My car would only do it under some load like yours. Idle was fine. You checked all the usual stuff - timing, FP, TPS. If cleaning the MAF doesnt work and you can rule out the plugs/plug wires, I'd start checking grounds. May be a bad TFI module as well?

**coralcoupe1993** · 07-18-2014, 05:37 PM

Crazy right! Ya, my wife has an antique plate on hers. My dad didnt understand when he saw it until I told him to count!

**coralcoupe1993** · 07-18-2014, 05:39 PM

Well I did everything. Down to regrounding. Decided last shot was a distributor. Put one in from the junk pile. BOOOOOM perfect. I dont know why, I dont care, the old one looks great, great output. Whatever reason another stock distributor fixed it up.

Car runs like a top. Now to find some stock E7s (well should do at least Gt40) so I can grab these twisted wedges for something made in the 60s!

**coralcoupe1993** · 07-18-2014, 05:41 PM

Does anyone have a set of Gt40/e7s and an exploorer intake? I dont want to really put all the E7 top end back on. Leaving that cam in so should have something better than stock. If I get some Gt40 stuff I will port match and clean up the bowls bla bla bla. God I am out of the 5.0 stuff. Sorry for the negativity! I need to snap back in.... my wifes car need some powa!

**PaxtonShelby** · 07-18-2014, 05:55 PM

Glad you were able to find a fix. What are you putting the TW's into Colin?

**PSPstang** · 07-18-2014, 11:34 PM

Originally Posted by coralcoupe1993

Does anyone have a set of Gt40/e7s and an exploorer intake? I dont want to really put all the E7 top end back on. Leaving that cam in so should have something better than stock. If I get some Gt40 stuff I will port match and clean up the bowls bla bla bla. God I am out of the 5.0 stuff. Sorry for the negativity! I need to snap back in.... my wifes car need some powa!

I still have a pair of lower mile e7s that I originally told you about.