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View Full Version : 93 Bucking Sometimes a small intake backfire


coralcoupe1993
07-17-2014, 09:50 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, 09:54 PM
Try cleaning the Maf.
coralcoupe1993
07-17-2014, 10:07 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, 10:07 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, 10:14 PM
we got some afm wires, and a 331 that doesnt buck, that will fix it.
John4cam
07-17-2014, 10:45 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!

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, 08:49 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, 04:37 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, 04:39 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, 04:41 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, 04:55 PM
Glad you were able to find a fix. What are you putting the TW's into Colin?
PSPstang
07-18-2014, 10:34 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!

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