93 5.0 notch fuel issue

ARMY93LX · April 14th, 2011, 08:33 PM

I am pretty sure it is a fuel issue.

I usually run 87. Last few tanks put in 93.
Timing is not advanced but maybe a few degrees up.
I recently replaced a few things. put in +2 plugs, cap, rotor, wires, coil. I replaced the fuel filter last weekend. I am replacing the pump this wkd. What size should I use?
When driving hitting the gas it hesitates, pops etc. sometimes. When driving or full throttle it has no go like it is running on a couple cylinders.
It revs up fine but if I hold it down it only revs up to around 4500 and sounds like it is running on a few cylinders.
It happens more when it is cold. A few times riding down the highway and hitting a dip or a bump it pops up front, like a backfire in the cylinder.
I am going to put a gauge on it this weekend and see what it reads.
What psi should it be reading when off, on and driving??
I want to install a gauge on it at the same time. I was thinking a 2 5/8" 0-100 psi gauge outside in front of the windshield.
Any pictures, thoughts, comments, concerns, advice would be greatly appreciated!

93hatch · April 14th, 2011, 08:54 PM

what the fuck is a +2 plug? whats your timing at?

ARMY93LX · April 14th, 2011, 09:35 PM

bosch plugs +2's
idk exactly what the timing is at. Had this guy check it and he said that it was at nothing but maybe a few degrees advanced.

ryanw · April 14th, 2011, 09:40 PM

you should ask your friend to be more specific with his info, for all we know hes doing it wrong...did he pull the spout connector before he checked the timing ?

ARMY93LX · April 14th, 2011, 10:20 PM

not sure didn't ask.

ARMY93LX · April 14th, 2011, 10:55 PM

what fuel pump should I get and how big?
I have stock injectors and mass air.
more info on the car:
CAI, 75mm throttle body, cobra upper and lower, pulleys, factory a/c, no smog, elec fan.
All upgraded from clutch to gears. spec stage 2, flywheel, fork, etc. all that.
A5 rated for 550hp, drive shaft, 3.55's

I plan on doing heads cam intake in the future. with a procharger in the far future.

ryanw · April 14th, 2011, 10:59 PM

I always say 255lph, that way it gives you room to grow and you only drop the tank one time. any extra fuel that your engine doesnt use will be sent back to the tank.

just my opinion

ARMY93LX · April 14th, 2011, 11:18 PM

thank you

428CJ · April 15th, 2011, 08:20 PM

MY car won't rev pass 4,500 rpms either! If i were you i would check your timing.

electricblue87 · April 16th, 2011, 12:42 AM

Check your firing order maybe you put a wire back on the wrong plug when you did your tune up

ARMY93LX · April 18th, 2011, 02:21 PM

Yea I just found this. I am going to check it out right now.

http://www.moddedmustangs.com/ford-firing-orders.html

Another thing is, If I cut the key off then back on real quick, it runs fine. But just for a moment then it's back to hesitating and popping.

Update. Over the weekend I changed the fuel pump. Installed a 255.

fogged306 · April 18th, 2011, 02:27 PM

Have you put a gauge on it yet? it should read 39psi at idle with the vac line off the regulator. Sounds like your pump is bad to me.

ARMY93LX · April 18th, 2011, 10:37 PM

Installed a 255 pump and an external gauge. The gauge reads 38-39 at idle and around 41 when I rev it up or get on it.
I am checking and adjusting the timing tomorrow. I should put it at 12 or 14?
Out of the few firing order pics I found, the one that works for now was the 1.3.7.2.6.5.4.8
The one that comes up that does not work at all is the 1.5.4.2.6.3.7.8

ryanw · April 18th, 2011, 10:45 PM

id put your timming at stock until you figure out the issue

Bubba95SN · April 19th, 2011, 12:11 AM

Remove the Bosch plugs and replace with copper core Motorcraft or Autolites. Bosch makes weird driveability issues. At dealer when there was a problem and the Bosch were in they went out.

ARMY93LX · April 19th, 2011, 06:24 PM

The timing was way advanced. Maybe like 20 or more. I set it at around 11-12.
I replaced the plugs with autolites.
re-checked the firing order. Made sure everything was tightened up. and.....
it is still doing it!

WTF else could it be???
Maybe the distributor?

Is that the right firing order?

I have been thru a few tanks of gas.

fogged306 · April 19th, 2011, 06:35 PM

You're on the correct firing order. That's the H.O firing order or the 351w order. The other is the non-HO firing order.

Next thing I would do is put a vac gauge on it and see what you come up with. Have you checked for vac leaks or blown intake gaskets?

ARMY93LX · April 19th, 2011, 09:35 PM

I am going to check that out today.

Vacuum gauge. Looks like this one?

http://www.google.com/products/catal...d=0CEEQ8gIwAg#

and how do I install this thing?
anyone have any pics?

1996 GT · April 19th, 2011, 10:30 PM

Octane Myths
read that, and make sure your distributor is tight and not slightly moved over.

Predator · April 20th, 2011, 10:23 AM

Ok... I'm having a similar problem with my 93 5.0 check the fuel pressure its prefect vacuum line on or off! The tps (throttle position sensor) is good!! I changed the fuel filter.. well my dad had a F-250 with a 460 with a head job, cam, and pistons pushing 400+ HP I own the truck now runs great he told me never to adjust the Distributer with a timing light it was like 36° advanced.. I put the timing light on my Mustang adjusted the timing to 10° it ran light total crap!!! Let my dad adjustedit runs alot better just still can't runt full throttle after he left I check the timing it was 30° advanced.... Next just for shits and giggles I unplugged my MAF sensor and drove it... it launched the hardest it ever has since I've owned it plug it in runs like crap ANYONE HAVE THOUGHTS ON THAT?

April 14th, 2011, 08:33 PM	#1
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	93 5.0 notch fuel issue I am pretty sure it is a fuel issue. I usually run 87. Last few tanks put in 93. Timing is not advanced but maybe a few degrees up. I recently replaced a few things. put in +2 plugs, cap, rotor, wires, coil. I replaced the fuel filter last weekend. I am replacing the pump this wkd. What size should I use? When driving hitting the gas it hesitates, pops etc. sometimes. When driving or full throttle it has no go like it is running on a couple cylinders. It revs up fine but if I hold it down it only revs up to around 4500 and sounds like it is running on a few cylinders. It happens more when it is cold. A few times riding down the highway and hitting a dip or a bump it pops up front, like a backfire in the cylinder. I am going to put a gauge on it this weekend and see what it reads. What psi should it be reading when off, on and driving?? I want to install a gauge on it at the same time. I was thinking a 2 5/8" 0-100 psi gauge outside in front of the windshield. Any pictures, thoughts, comments, concerns, advice would be greatly appreciated! Last edited by ARMY93LX; April 14th, 2011 at 08:46 PM.

April 14th, 2011, 08:54 PM	#2
93hatch Banned 1992 Lx 11.39@119.24 Join Date: Jan 2008 Location: Az Posts: 11,644 iTrader: 0 reviews	what the fuck is a +2 plug? whats your timing at? __________________ [QUOTE=93mustank;2577445]We speed tested my right arm for quickness in shifts... So he could design the cam for proper shift recovery.[/QUOTE]

April 14th, 2011, 09:40 PM	#4
ryanw I Post Entirely Way Too Much 1991 Ford Mustang GT Join Date: May 2007 Location: San Diego, California Posts: 6,059 iTrader: 0 reviews	you should ask your friend to be more specific with his info, for all we know hes doing it wrong...did he pull the spout connector before he checked the timing ? __________________ DART 331ci stroker, AFR 185 heads, Trick Flow R intake, Accufab 70mm tb, 75mm pro m Maf, 30lb injectors, jba headers, 2 1/2" x pipe flowmaster super 10 mufflers, 255 fuel pump, 3:27 gears

April 14th, 2011, 10:59 PM	#7
ryanw I Post Entirely Way Too Much 1991 Ford Mustang GT Join Date: May 2007 Location: San Diego, California Posts: 6,059 iTrader: 0 reviews	I always say 255lph, that way it gives you room to grow and you only drop the tank one time. any extra fuel that your engine doesnt use will be sent back to the tank. just my opinion __________________ DART 331ci stroker, AFR 185 heads, Trick Flow R intake, Accufab 70mm tb, 75mm pro m Maf, 30lb injectors, jba headers, 2 1/2" x pipe flowmaster super 10 mufflers, 255 fuel pump, 3:27 gears

April 15th, 2011, 08:20 PM	#9
428CJ Regular Join Date: Oct 2010 Location: Boise, Id Posts: 142 iTrader: 0 reviews	MY car won't rev pass 4,500 rpms either! If i were you i would check your timing. __________________ 1988 Mustang: 5 speed, hurst shifter, plenty slow.

April 14th, 2011, 09:35 PM	#3
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	bosch plugs +2's idk exactly what the timing is at. Had this guy check it and he said that it was at nothing but maybe a few degrees advanced.

April 14th, 2011, 10:20 PM	#5
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	not sure didn't ask.

April 14th, 2011, 10:55 PM	#6
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	what fuel pump should I get and how big? I have stock injectors and mass air. more info on the car: CAI, 75mm throttle body, cobra upper and lower, pulleys, factory a/c, no smog, elec fan. All upgraded from clutch to gears. spec stage 2, flywheel, fork, etc. all that. A5 rated for 550hp, drive shaft, 3.55's I plan on doing heads cam intake in the future. with a procharger in the far future.

April 14th, 2011, 11:18 PM	#8
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	thank you

April 16th, 2011, 12:42 AM	#10
electricblue87 Newbie 87 MUSTANG GT 12.87@107 Join Date: Dec 2009 Location: NEW YORK Posts: 42 iTrader: 0 reviews	Check your firing order maybe you put a wire back on the wrong plug when you did your tune up

April 18th, 2011, 02:21 PM	#11
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	Yea I just found this. I am going to check it out right now. http://www.moddedmustangs.com/ford-firing-orders.html Another thing is, If I cut the key off then back on real quick, it runs fine. But just for a moment then it's back to hesitating and popping. Update. Over the weekend I changed the fuel pump. Installed a 255. Last edited by ARMY93LX; April 19th, 2011 at 06:27 PM.

April 18th, 2011, 02:27 PM	#12
fogged306 MM Fanatic 89 GT Join Date: Apr 2007 Location: NY Posts: 4,875 iTrader: 2 reviews	Have you put a gauge on it yet? it should read 39psi at idle with the vac line off the regulator. Sounds like your pump is bad to me.

April 18th, 2011, 10:37 PM	#13
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	Installed a 255 pump and an external gauge. The gauge reads 38-39 at idle and around 41 when I rev it up or get on it. I am checking and adjusting the timing tomorrow. I should put it at 12 or 14? Out of the few firing order pics I found, the one that works for now was the 1.3.7.2.6.5.4.8 The one that comes up that does not work at all is the 1.5.4.2.6.3.7.8

April 18th, 2011, 10:45 PM	#14
ryanw I Post Entirely Way Too Much 1991 Ford Mustang GT Join Date: May 2007 Location: San Diego, California Posts: 6,059 iTrader: 0 reviews	id put your timming at stock until you figure out the issue __________________ DART 331ci stroker, AFR 185 heads, Trick Flow R intake, Accufab 70mm tb, 75mm pro m Maf, 30lb injectors, jba headers, 2 1/2" x pipe flowmaster super 10 mufflers, 255 fuel pump, 3:27 gears

April 19th, 2011, 12:11 AM	#15
Bubba95SN Regular 1995 Mustang GT Join Date: Feb 2011 Location: Jacksonville NC Posts: 211 iTrader: 0 reviews	Remove the Bosch plugs and replace with copper core Motorcraft or Autolites. Bosch makes weird driveability issues. At dealer when there was a problem and the Bosch were in they went out.

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April 19th, 2011, 06:24 PM	#16
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	The timing was way advanced. Maybe like 20 or more. I set it at around 11-12. I replaced the plugs with autolites. re-checked the firing order. Made sure everything was tightened up. and..... it is still doing it! WTF else could it be??? Maybe the distributor? Is that the right firing order? I have been thru a few tanks of gas.

April 19th, 2011, 06:35 PM	#17
fogged306 MM Fanatic 89 GT Join Date: Apr 2007 Location: NY Posts: 4,875 iTrader: 2 reviews	You're on the correct firing order. That's the H.O firing order or the 351w order. The other is the non-HO firing order. Next thing I would do is put a vac gauge on it and see what you come up with. Have you checked for vac leaks or blown intake gaskets?

April 19th, 2011, 09:35 PM	#18
ARMY93LX Newbie 1993 MUSTANG LX 5.0 NOTCH unknown at this time Join Date: Apr 2011 Location: Ft. Bragg Posts: 14 iTrader: 0 reviews	I am going to check that out today. Vacuum gauge. Looks like this one? http://www.google.com/products/catal...d=0CEEQ8gIwAg# and how do I install this thing? anyone have any pics? Last edited by ARMY93LX; April 20th, 2011 at 07:14 AM.

April 19th, 2011, 10:30 PM	#19
1996 GT Traction...? 1996 GT/ 2008 GT Vert Join Date: Nov 2010 Location: Canada Posts: 2,207 iTrader: 0 reviews	Octane Myths read that, and make sure your distributor is tight and not slightly moved over.

April 20th, 2011, 10:23 AM	#20
Predator Regular 1993 Mustang GT 5.0 Join Date: Dec 2010 Location: Henderson Posts: 99 iTrader: 0 reviews	Ok... I'm having a similar problem with my 93 5.0 check the fuel pressure its prefect vacuum line on or off! The tps (throttle position sensor) is good!! I changed the fuel filter.. well my dad had a F-250 with a 460 with a head job, cam, and pistons pushing 400+ HP I own the truck now runs great he told me never to adjust the Distributer with a timing light it was like 36° advanced.. I put the timing light on my Mustang adjusted the timing to 10° it ran light total crap!!! Let my dad adjustedit runs alot better just still can't runt full throttle after he left I check the timing it was 30° advanced.... Next just for shits and giggles I unplugged my MAF sensor and drove it... it launched the hardest it ever has since I've owned it plug it in runs like crap ANYONE HAVE THOUGHTS ON THAT? __________________ 1993 Mustang GT 5.0 BBK cold air intake, upper and lower control arms, Ford Racing Plug Wires, Under driven pulleys, subframe connectors, King Cobra clutch, adjustable clutch cable....

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