Car is messing up at higher rpms, every so often

GStam66 · May 13th, 2007, 06:30 PM

Alright, ive been noticing this happening more and more frequently in my 99 mustang gt (auto). Ill be cruisin along at any speed, and when i floor it, the car will climb to about 3500-4000 rpms, then start jerking and not climbing anymore. When i let off the gas a little bit, it will climb higher, but still jerk and bog. I have to go down to at least 75% throttle for the car to hit 5300, and shift.

At first i thought it would be air or fuel related so we checked out all the sensors and made sure they were clean, and the filters. The car was running fine before we did the filters but we changed em anyway and cleaned the throttle position sensor. Car drove fine for a couple hours then started messing up again.

I have vids of it happening, watch the needle and listen for the car jerking and making noise.

My friend who works on mustangs said it might be a bad tps, kickdown cable, or maybe the tranny governor. Any ideas?

GStam66 · May 13th, 2007, 06:31 PM

Damn, i cant post the vids till tomorrow, great.

Garhfer · May 13th, 2007, 07:02 PM

I had the similiar problem on a dodge truck I had once, and it was the fuel pump going bad.

ujslost · May 13th, 2007, 07:16 PM

spark plugs possibly or faulty coil pack

ujslost · May 13th, 2007, 07:16 PM

r u getting a check engine light?
what code does it show

GStam66 · May 13th, 2007, 07:32 PM

No check engine light. No codes, changed the spark plugs last month. Coil packs are good. I noticed this issue happening about 4 days ago.

tlr96 · May 13th, 2007, 09:01 PM

did you double check the wires to make sure you got them back on all the way?

El_Cangri · May 13th, 2007, 09:15 PM

it may be the fuel pump going bad making it not able to deliver enougth fuel at the high rpm.... Garhfer your car in the sig looks sexy

GStam66 · May 13th, 2007, 11:01 PM

Hmm, correction. Apparently my buddy didnt clean the tps, he cleaned the idle air control. Sorry. Yes the plugs are good.

GStam66 · May 14th, 2007, 12:02 AM

also, doesnt a bad fuel pump make a whining noise?

Garhfer · May 14th, 2007, 12:32 AM

Originally Posted by GStam66

also, doesnt a bad fuel pump make a whining noise?

Not always, on Dodges it does make a little ringing noise but I don't think so on Fords

Badasstang281 · May 14th, 2007, 01:34 AM

Try replacing you’re fuel filter when I got me car it was doing the same thing

Garhfer · May 14th, 2007, 01:37 AM

Originally Posted by Badasstang281

Try replacing you’re fuel filter when I got me car it was doing the same thing

Heh, he already said he changed that.

Badasstang281 · May 14th, 2007, 01:41 AM

Awww shit I must read all of the post …. Dam it

GStam66 · May 14th, 2007, 02:04 AM

well, im takin it to a tranny shop tomorrow, hopefully it messes up for the guy when hes driving it. If not ill just have to show him the vids of it messing up and do my best to explain it.

GStam66 · May 14th, 2007, 04:38 PM

well the mechs took it for 2 drives. the first one they couldnt find an issue, the second one it was messing up for em. They said the tranny was fine, and that it wasnt the governor at all. They said it had to be a fuel issue, cause it definitely felt like the car was "starving" when it was jerking. They suggested to run a tank of premium, cause it coulda been a bad mixture of gas, and if it still fucks up, to check the fuel pressure, then the a/f ratio. Cause it might be the pump also.

Any idea what fuel psi i should be looking for? whats considered normal?

Garhfer · May 14th, 2007, 06:41 PM

Originally Posted by GStam66

well the mechs took it for 2 drives. the first one they couldnt find an issue, the second one it was messing up for em. They said the tranny was fine, and that it wasnt the governor at all. They said it had to be a fuel issue, cause it definitely felt like the car was "starving" when it was jerking. They suggested to run a tank of premium, cause it coulda been a bad mixture of gas, and if it still fucks up, to check the fuel pressure, then the a/f ratio. Cause it might be the pump also.

Any idea what fuel psi i should be looking for? whats considered normal?

Do you even have fuel pressure gauges?

ujslost · May 14th, 2007, 06:47 PM

my bet is on a coil or a spark plug

Garhfer · May 14th, 2007, 06:58 PM

Originally Posted by ujslost

my bet is on a coil or a spark plug

I'm telling ya it's the fuel pump!!! FUEL PUMP FTW! lol

GStam66 · May 15th, 2007, 01:26 AM

nah, my friend is gonna get one from his job.

The car did fine all morning, but as i drove it for longer periods of time, it messed up earlier and earlier. After an hour of nonstop driving, i was doin 50, and could only hit the throttle halfway and ease it up to speed, cause it would start messin up at 3000 if i hit the throttle more than 50%. I got to my friends house, let it sit for an hour, drove it again, and it was fine.

Its gotta be the pump, right? all filters/sensors check out, as does the tranny. I threw a tank of 93 in there, to help clean out and flush out the possibly shitty gas from before.

Now i gotta find a fuel pump for a decent price. Autozone wants 250 for one!

May 13th, 2007, 06:30 PM	#1
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	Car is messing up at higher rpms, every so often Alright, ive been noticing this happening more and more frequently in my 99 mustang gt (auto). Ill be cruisin along at any speed, and when i floor it, the car will climb to about 3500-4000 rpms, then start jerking and not climbing anymore. When i let off the gas a little bit, it will climb higher, but still jerk and bog. I have to go down to at least 75% throttle for the car to hit 5300, and shift. At first i thought it would be air or fuel related so we checked out all the sensors and made sure they were clean, and the filters. The car was running fine before we did the filters but we changed em anyway and cleaned the throttle position sensor. Car drove fine for a couple hours then started messing up again. I have vids of it happening, watch the needle and listen for the car jerking and making noise. My friend who works on mustangs said it might be a bad tps, kickdown cable, or maybe the tranny governor. Any ideas?

May 13th, 2007, 07:02 PM	#3
Garhfer Hardcore Enthusiast 2004 Mustang GT Conv. Join Date: Mar 2007 Location: Edgewater, FL Posts: 1,793 iTrader: 0 reviews	I had the similiar problem on a dodge truck I had once, and it was the fuel pump going bad. __________________ 2004 GT Boosted by Vortech

May 13th, 2007, 07:16 PM	#4
ujslost MM Fanatic Join Date: Mar 2007 Location: Albertville, AL Posts: 3,920 Blog Entries: 1 iTrader: 1 reviews	spark plugs possibly or faulty coil pack __________________ 1986 Mustang GT t-top time piece!

May 13th, 2007, 07:16 PM	#5
ujslost MM Fanatic Join Date: Mar 2007 Location: Albertville, AL Posts: 3,920 Blog Entries: 1 iTrader: 1 reviews	r u getting a check engine light? what code does it show __________________ 1986 Mustang GT t-top time piece!

May 13th, 2007, 09:01 PM	#7
tlr96 Hardcore Enthusiast 1996 Mustang GT Join Date: Mar 2007 Location: Effingham, IL Posts: 1,795 iTrader: 0 reviews	did you double check the wires to make sure you got them back on all the way? __________________ view my garage for pics and modifications listen to my exhaust video 1 video 2 video 3

May 13th, 2007, 06:31 PM	#2
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	Damn, i cant post the vids till tomorrow, great.

May 13th, 2007, 07:32 PM	#6
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	No check engine light. No codes, changed the spark plugs last month. Coil packs are good. I noticed this issue happening about 4 days ago.

May 13th, 2007, 11:01 PM	#9
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	Hmm, correction. Apparently my buddy didnt clean the tps, he cleaned the idle air control. Sorry. Yes the plugs are good.

May 14th, 2007, 12:02 AM	#10
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	also, doesnt a bad fuel pump make a whining noise?

May 14th, 2007, 01:34 AM	#12
Badasstang281 Regular Join Date: Jan 2007 Location: Albuquerque, NM Posts: 385 iTrader: 0 reviews	Try replacing you’re fuel filter when I got me car it was doing the same thing __________________ BBK cai P&P 75mmtb P&P plenum BASSANI exhaust MAC x-pipe NO CAT"S ACCEL direct fire coils NGK iridium spark plugs lX7 Eibach pro-kit springs

May 14th, 2007, 01:41 AM	#14
Badasstang281 Regular Join Date: Jan 2007 Location: Albuquerque, NM Posts: 385 iTrader: 0 reviews	Awww shit I must read all of the post …. Dam it __________________ BBK cai P&P 75mmtb P&P plenum BASSANI exhaust MAC x-pipe NO CAT"S ACCEL direct fire coils NGK iridium spark plugs lX7 Eibach pro-kit springs

May 14th, 2007, 02:04 AM	#15
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	well, im takin it to a tranny shop tomorrow, hopefully it messes up for the guy when hes driving it. If not ill just have to show him the vids of it messing up and do my best to explain it.

May 14th, 2007, 04:38 PM	#16
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	well the mechs took it for 2 drives. the first one they couldnt find an issue, the second one it was messing up for em. They said the tranny was fine, and that it wasnt the governor at all. They said it had to be a fuel issue, cause it definitely felt like the car was "starving" when it was jerking. They suggested to run a tank of premium, cause it coulda been a bad mixture of gas, and if it still fucks up, to check the fuel pressure, then the a/f ratio. Cause it might be the pump also. Any idea what fuel psi i should be looking for? whats considered normal?

May 14th, 2007, 06:47 PM	#18
ujslost MM Fanatic Join Date: Mar 2007 Location: Albertville, AL Posts: 3,920 Blog Entries: 1 iTrader: 1 reviews	my bet is on a coil or a spark plug __________________ 1986 Mustang GT t-top time piece!

May 15th, 2007, 01:26 AM	#20
GStam66 Newbie Join Date: May 2007 Posts: 16 iTrader: 0 reviews	nah, my friend is gonna get one from his job. The car did fine all morning, but as i drove it for longer periods of time, it messed up earlier and earlier. After an hour of nonstop driving, i was doin 50, and could only hit the throttle halfway and ease it up to speed, cause it would start messin up at 3000 if i hit the throttle more than 50%. I got to my friends house, let it sit for an hour, drove it again, and it was fine. Its gotta be the pump, right? all filters/sensors check out, as does the tranny. I threw a tank of 93 in there, to help clean out and flush out the possibly shitty gas from before. Now i gotta find a fuel pump for a decent price. Autozone wants 250 for one!

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