Car sputters at high rpm...

Stang_Crazy · 03-19-2001, 08:05 PM

I raced my buddy the other day and when we raced, my car was pulling good until about 4000 rpm. It started to sputter and could barely get up to 5000. We raced again and it did the same thing. It only happens under full throttle and only after 4000 rpm. I had put fuel system cleaner in it earlier that same day. Could the treatment be causing this to happen?? Is my fuel pump going bad?? I'm totally lost as to what the problem might be...

------------------
91 GT AOD: 3.73's, Pulleys,PI Converter, 14.71@91.78mph
(before pulleys)

lx mike · 03-19-2001, 08:18 PM

it just started after you used the fuel system cleaner?? try running your gas tank down as far as possible and refill all the way and see if that does aything. if your fuel pump is going bad it would start to whine loud.

------------------
93-LX: 5 Speed, Flow's with H-Pipe, 3.73's Sub's and K&N.

gt93mustang · 03-19-2001, 08:49 PM

I would have to second that opinion. Check the fuel system over really well, changing your filter and making sure the fuel pump is not going bad.

------------------
MAC equal length headers, MAC Off-Road H-Pipe, Flowmaster mufflers, 373's, March ram-air kit, underdrive pulleys, 73mm MAF, 75mm TB, Saleen Intake (ported), Edelbrock 6037 heads (ported, polished, 3 angle valve-job 255CFM @.500), 1.6 FMS RR's, Wolverine 1087 Cam, 24lb injectors, MSD 6AL, Subframe connectors, Griggs Adustable Lower Control Arms, Lakewood 50/50 shocks, SSM Upper Control Arms... and probably some more in there I forgot

03-20-2001, 01:49 AM

My car was doing the same thing the day of the motor install. come to find out it was the PLUG that hooks the mass air up had severe corrosion.. that fixed me up bud!

------------------
SOLD THE 87GT, 83 Hatch EFI converted.
Cobra shortblcok with TFS heads, E-303 cam, GT40 intake 65mm TB and 75 bullet TKO tranny 3.73 gears ROH wheels, and ALWAYS a 150 shot of Compucar

StreetStang37 · 03-20-2001, 04:48 AM

I had the same thing happen to me but it went away when I changed my alternator. But then again I put in my ram air at about the same time and had to take off the MAF to put it in right. Maybe it was the MAF sensor that had a bad connection, I dunno....

------------------
1993 Mustang GT - March Ram Air & Pullies, K&N, C&L 73mm MAF, Super Competition Hooker Headers, 2 1/2 in. mandrel bent cat back, High Flow H-Pipe, Pro 5.0 Shifter, 16* Timing Advance

LX XLR8R · 03-20-2001, 11:48 AM

cutting off at high rpms like that is usually lack of fuel(time for a 190lph fuel pump

)..if it was choppy but still pulling till redline then it would be spark(i.e. prolly a burnt wire but dont rule out plugz)

------------------
1987 black notch(ex 4 banger)
DSS 306 w/ main support...Elderbrock 6028 heads..gt-40 intake..24# injectors...70 mm tb..77 pro-m...accel 300+..mac full legnth..tremec w/ pro5oh...full MAC exhaust,off road h-pipe,long tubes, catback...ron davis radiator..subframes, control arms...CFDF II..o yea holley FPR sucks..dont buy one..
AIM=onesillynotch

Stang_Crazy · 03-20-2001, 12:09 PM

It actually was still pulling but not as hard and not as fast. I guess it's time for a spring tune up...

------------------
91 GT AOD: 3.73's, Pulleys,PI Converter, 14.71@91.78mph
(before pulleys)

03-20-2001, 10:35 PM

IF you put all of that cleaner stuff in at one time it could've knocked enough stuff loose to clog the fuel line. If i were you i'd replace the fuel filter see what happens. I've heard of this happening and a guy at a shop i used to work at says he loves the fuel injection cleaner stuff because it gives him alot of work. I've heard it can be used successfully 1/2 bottle at a time after being filled full to the top with gas, but i'd never use it. Good luck i hope you find the problem

------------------
'84 Mustang 5.0 T5, FMS aluminum radiator & 180* thermostat, 1 5/8 shortys/2.5" duals, '88 GT tail lights and wheels, Holley 4160 4 BBL, smog pump idler, more coming soon

LX XLR8R · 03-21-2001, 12:14 PM

well when you run out of fuel thats it and ur car wont go past a certain rpm..if you have 1 burnt wire arcing on the header than say from idle to 4000 pulls ok then past thier it pulls alot slower and is sputtery

------------------
1987 black notch(ex 4 banger)
DSS 306 w/ main support...Elderbrock 6028 heads..gt-40 intake..24# injectors...70 mm tb..77 pro-m...accel 300+..mac full legnth..tremec w/ pro5oh...full MAC exhaust,off road h-pipe,long tubes, catback...ron davis radiator..subframes, control arms...CFDF II..o yea holley FPR sucks..dont buy one..
AIM=onesillynotch

mustang17 · 03-21-2001, 01:35 PM

This sounds like more of an MAF problem to me. I had the same symptoms you describe. My check engine light would also go on sometimes under WOT. A code scan revealed the MAF code.

I would make sure the connection is al right and run a code scan before undertaking a fuel pump project. I(and some people on this site)thought mine was fuel related at first. Turned out to be a much easier fix.
Good luck.

------------------
1995 GT Black- Edelbrock 6037's,Edelbrock,proformrintake,Edelbrock cam,70mm TB,75mm pro-m,Taylor wires, pulleys,Equal length headers,K&N filter
Flowmaster,3.73's, Eibach pro rate springs
lower control arms Centerforce clutch
New motor in the works!

03-19-2001, 08:05 PM	#1
Stang_Crazy It's never clean enough! Join Date: Jan 1999 Location: Shaler, PA Posts: 1,542	Car sputters at high rpm... I raced my buddy the other day and when we raced, my car was pulling good until about 4000 rpm. It started to sputter and could barely get up to 5000. We raced again and it did the same thing. It only happens under full throttle and only after 4000 rpm. I had put fuel system cleaner in it earlier that same day. Could the treatment be causing this to happen?? Is my fuel pump going bad?? I'm totally lost as to what the problem might be... ------------------ 91 GT AOD: 3.73's, Pulleys,PI Converter, 14.71@91.78mph (before pulleys)

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03-19-2001, 08:18 PM	#2
lx mike Undescribable Join Date: Sep 1998 Location: Ft Myers Fla Posts: 1,539	it just started after you used the fuel system cleaner?? try running your gas tank down as far as possible and refill all the way and see if that does aything. if your fuel pump is going bad it would start to whine loud. ------------------ 93-LX: 5 Speed, Flow's with H-Pipe, 3.73's Sub's and K&N.

03-19-2001, 08:49 PM	#3
gt93mustang Registered Member Join Date: Feb 1999 Location: Kennesaw, Georgia, USA Posts: 252	I would have to second that opinion. Check the fuel system over really well, changing your filter and making sure the fuel pump is not going bad. ------------------ MAC equal length headers, MAC Off-Road H-Pipe, Flowmaster mufflers, 373's, March ram-air kit, underdrive pulleys, 73mm MAF, 75mm TB, Saleen Intake (ported), Edelbrock 6037 heads (ported, polished, 3 angle valve-job 255CFM @.500), 1.6 FMS RR's, Wolverine 1087 Cam, 24lb injectors, MSD 6AL, Subframe connectors, Griggs Adustable Lower Control Arms, Lakewood 50/50 shocks, SSM Upper Control Arms... and probably some more in there I forgot

03-20-2001, 01:49 AM	#4
87GTman Guest Posts: n/a	My car was doing the same thing the day of the motor install. come to find out it was the PLUG that hooks the mass air up had severe corrosion.. that fixed me up bud! ------------------ SOLD THE 87GT, 83 Hatch EFI converted. Cobra shortblcok with TFS heads, E-303 cam, GT40 intake 65mm TB and 75 bullet TKO tranny 3.73 gears ROH wheels, and ALWAYS a 150 shot of Compucar

03-20-2001, 04:48 AM	#5
StreetStang37 Registered Member Join Date: Dec 2000 Location: San Jose, California USA Posts: 275	I had the same thing happen to me but it went away when I changed my alternator. But then again I put in my ram air at about the same time and had to take off the MAF to put it in right. Maybe it was the MAF sensor that had a bad connection, I dunno.... ------------------ 1993 Mustang GT - March Ram Air & Pullies, K&N, C&L 73mm MAF, Super Competition Hooker Headers, 2 1/2 in. mandrel bent cat back, High Flow H-Pipe, Pro 5.0 Shifter, 16* Timing Advance

03-20-2001, 11:48 AM	#6
LX XLR8R Dirk Diggler Join Date: Feb 1999 Location: SLOATSBURG, NY Posts: 1,931	cutting off at high rpms like that is usually lack of fuel(time for a 190lph fuel pump )..if it was choppy but still pulling till redline then it would be spark(i.e. prolly a burnt wire but dont rule out plugz) ------------------ 1987 black notch(ex 4 banger) DSS 306 w/ main support...Elderbrock 6028 heads..gt-40 intake..24# injectors...70 mm tb..77 pro-m...accel 300+..mac full legnth..tremec w/ pro5oh...full MAC exhaust,off road h-pipe,long tubes, catback...ron davis radiator..subframes, control arms...CFDF II..o yea holley FPR sucks..dont buy one.. AIM=onesillynotch

03-20-2001, 12:09 PM	#7
Stang_Crazy It's never clean enough! Join Date: Jan 1999 Location: Shaler, PA Posts: 1,542	It actually was still pulling but not as hard and not as fast. I guess it's time for a spring tune up... ------------------ 91 GT AOD: 3.73's, Pulleys,PI Converter, 14.71@91.78mph (before pulleys)

03-20-2001, 10:35 PM	#8
84stang83zephyr Guest Posts: n/a	IF you put all of that cleaner stuff in at one time it could've knocked enough stuff loose to clog the fuel line. If i were you i'd replace the fuel filter see what happens. I've heard of this happening and a guy at a shop i used to work at says he loves the fuel injection cleaner stuff because it gives him alot of work. I've heard it can be used successfully 1/2 bottle at a time after being filled full to the top with gas, but i'd never use it. Good luck i hope you find the problem ------------------ '84 Mustang 5.0 T5, FMS aluminum radiator & 180* thermostat, 1 5/8 shortys/2.5" duals, '88 GT tail lights and wheels, Holley 4160 4 BBL, smog pump idler, more coming soon

03-21-2001, 12:14 PM	#9
LX XLR8R Dirk Diggler Join Date: Feb 1999 Location: SLOATSBURG, NY Posts: 1,931	well when you run out of fuel thats it and ur car wont go past a certain rpm..if you have 1 burnt wire arcing on the header than say from idle to 4000 pulls ok then past thier it pulls alot slower and is sputtery ------------------ 1987 black notch(ex 4 banger) DSS 306 w/ main support...Elderbrock 6028 heads..gt-40 intake..24# injectors...70 mm tb..77 pro-m...accel 300+..mac full legnth..tremec w/ pro5oh...full MAC exhaust,off road h-pipe,long tubes, catback...ron davis radiator..subframes, control arms...CFDF II..o yea holley FPR sucks..dont buy one.. AIM=onesillynotch

03-21-2001, 01:35 PM	#10
mustang17 Registered Member Join Date: Sep 2000 Location: Concord, MA, USA Posts: 264	This sounds like more of an MAF problem to me. I had the same symptoms you describe. My check engine light would also go on sometimes under WOT. A code scan revealed the MAF code. I would make sure the connection is al right and run a code scan before undertaking a fuel pump project. I(and some people on this site)thought mine was fuel related at first. Turned out to be a much easier fix. Good luck. ------------------ 1995 GT Black- Edelbrock 6037's,Edelbrock,proformrintake,Edelbrock cam,70mm TB,75mm pro-m,Taylor wires, pulleys,Equal length headers,K&N filter Flowmaster,3.73's, Eibach pro rate springs lower control arms Centerforce clutch New motor in the works!