• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Fuel upgrades, car won't run. Need help ASAP! :(

  • Thread starter Thread starter Ozz
  • Start date Start date Apr 12, 2004
  • 1
  • 2
  • 3
  • 4
Next
1 of 4 Next Last

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 12, 2004
#1
  • Apr 12, 2004
  • #1
I've been over this before, some might recognize it, and it's back.

What I began with on my 92 5.0:
typhoon intake and vortech a-trim, MSD blaster TFI coil

What i added:
255lph fuel pump, 30# injectors, 75mm MAF matched to 30#s, 70mm throttle body, AFPR

A month or so ago we solved this, and it ended up being the stock fuel filter which I didn't change. It ran!

I took some time to put on new headers, H pipe and do a brake job, and when I went to start it up again it did not run. It would start and run for about 3 seconds, then will die. Pressing the throttle won't keep it running either. It will start up immediately after dying, too.

I put in a brand new fuel filter and it didn't help out, so I'm just stuck.

I took out a plug and it looks like this:



It's real dark gray/black, and a friend told me that they should still work despite that.

So where should I look and what can I do?

Fuel pressure is set at 30 and it holds as the car runs.

Lots of people have suggested me to get a chip, and I have that in my plans. But the bad part is, I HAVE TO DRIVE THE CAR DOWN TO GET TUNED and the chip burned. What's worse is this is in under a week! I've gotta get this damn thing running.

What I also don't understand is that tons of people have put in new injectors & MAF and have been able to run their car, what is my problem? The injectors aren't leaking either. The entire setup was running just a month ago and now it's not.

Please help!
 

TC93

Well-Known Member
Sep 11, 2000
2,075
1
57
Ellerslie GA 31807
Apr 12, 2004
#2
  • Apr 12, 2004
  • #2
Check the IAB.. My old 88Gt did the same once,, drove it to the post office and it acted just like you mentioned. Turned out the IAB need cleaning. Took it off cleaned it out and car fired right up..
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 12, 2004
#3
  • Apr 12, 2004
  • #3
I will do it. I will f'n do anything right about now. Like I said, not even a week until i need this running

Could you just tell me what to do to clean it?
 

TC93

Well-Known Member
Sep 11, 2000
2,075
1
57
Ellerslie GA 31807
Apr 12, 2004
#4
  • Apr 12, 2004
  • #4
mansonozz said:
I will do it. I will f'n do anything right about now. Like I said, not even a week until i need this running

Could you just tell me what to do to clean it?
Click to expand...

You can clean with carb or throttle body cleaner. Unplug it, remove the 2 8mm bolts and spray in the back side in the 2 holes. Let it dry and replace, but be sure that gasket didn't get messed up when removing it.
 

4dStang

Banned
Oct 23, 2002
718
1
0
Near St Louis, Missouri
Apr 13, 2004
#5
  • Apr 13, 2004
  • #5
You said you just changed the fuel pump? I would take a look at that. Watch the pressure to see if it stays at the pressure you set while it runs the little it does. If you just changed the pump, and it is has drivability problems (like a fuel problem), I would definatly look at the pump first.

Let us know how it turns out.

CB
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#6
  • Apr 13, 2004
  • #6
Yes the FP stays until the car dies. THen it drops down to about 20psi.
What should I look at on the fuel pump?
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#7
  • Apr 13, 2004
  • #7
I cleaned the IAB, no difference.
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#8
  • Apr 13, 2004
  • #8
bump, hoping for some new eyes for new ideas.
 

BlackFox5.0

Founding Member
Aug 7, 2000
3,514
1
0
Massachusetts
Apr 13, 2004
#9
  • Apr 13, 2004
  • #9
Is it just not idling? Do you have a bypass valve hooked up? Will it run without the blower hooked up? if you haven't tried that, it's worth a shot, mine wouldn't run with the blower hooked up, so I put the filter and MAF back on the TB and it ran like it should. once that blower goes on it gets all crazy and didn't want to idle, so I had to raise my idle just by turning in the idle screw. it runs now and doesn't stall anymore, but If it still does it after I get my bypass put in, then I will get one of those air bypass plates for my IAB, which i was told by 2 people who have them, work pretty well...
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#10
  • Apr 13, 2004
  • #10
It starts, runs for 2-3 seconds, then dies. Every damn time.
I haven't tried it without the blower hooked up. But that really shouldn't make a difference since I was running it with the blower perfectly before any fuel upgrades were done. Now that I am getting more fuel, the damn thing won't run. It worked better with 19# injectors/maf and 88lph fuel pump!!
 

BlackFox5.0

Founding Member
Aug 7, 2000
3,514
1
0
Massachusetts
Apr 13, 2004
#11
  • Apr 13, 2004
  • #11
The injectors only extend the limits of how much MAX fuel you get. At idle the injecotrs should put out just enough fuel for the amount of air thats coming into the engine, according to what the maf meter says. I hope your using a Pro-M. Eeven then, not every maf meter might work, theres always a defect, if you think thats the problem, then try a different one.
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#12
  • Apr 13, 2004
  • #12
Update time:

1. I unhooked the MAF from the blower (still left it plugged in) and tried to run the car, no luck
2. I unplugged the MAF electronics and yanked it from the car, still no luck
3. I put the MAF back in, hooked it up, and bumped the fuel pressure down, up, etc. I've got it as close to 38psi WITH vacuum as I can get (damn thing won't idle long enough to set it perfectly).

I WAS able to keep it running by pushing the gas pedal TO THE FLOOR. And even then it was bucking badly and almost choking itself out. The exhaust would stop flowing and then it would kick back in, and repeat itself after a few seconds. I was able to keep it going like that for quite a while but ONLY when I pushed the pedal way down to the floor. Any less and it died out.

So does that open any new ideas up? The MAF doesn't seem to be the problem now, right?
 

BlackFox5.0

Founding Member
Aug 7, 2000
3,514
1
0
Massachusetts
Apr 13, 2004
#13
  • Apr 13, 2004
  • #13
damn...are you sure the firing order is right? my friend made that mistake, he thought he blew a headgasket, but if your flooring it and it's not running even then, then something is wrong...have someone start it and let it run for a sec, then unplug the MAF, any change or still the same? Again, the same thing happened with my friends car. He wasn't getting a signal from the meter....
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#14
  • Apr 13, 2004
  • #14
Yea man, they're correct. I marked them when I changed my headers, and they were def. correct before the whole ordeal when it did run.
 

TC93

Well-Known Member
Sep 11, 2000
2,075
1
57
Ellerslie GA 31807
Apr 13, 2004
#15
  • Apr 13, 2004
  • #15
Have you re-checked all the upgrades you did?? Just to rule out anything you might have missed? Also what about the upper to lower intake, maybe be something maybe holding them apart alittle bit and getting a massive vacum leak. Re-check everthing and all connections just to be sure, might have forgot to plug something in. If everything is good,,,,Then check the TPS voltage. With the car off and key on see what he voltage is at WOT. It should be in the high 4's close to 5 volts. Also see what it is at what would be idle without pressing the gas pedal. Did you unhook the ground on the injector harness that goes to the back of the head when replacing the injectors?? If so check that to make sure it is connected...
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#16
  • Apr 13, 2004
  • #16
Have you re-checked all the upgrades you did??
Click to expand...

The fuel pump is ok, the exhaust is all good, TB is good. I will check that injector ground harness. Can you tell me which side of the head it connects to? So much crap down there that if I don't knowwhat I'm lookin for I will never find it

Then check the TPS voltage. With the car off and key on see what he voltage is at WOT. It should be in the high 4's close to 5 volts
Click to expand...

My TPS is not correct, I know that. But last time the car ran, it was not set correctly either. I posted about that and also noted that the car idled PERFECTLY and revved up and came down perfectly as well. Everyone said to leave the TPS alone if that was the case, and consider myself lucky.

Even if the TPS was not set correctly, shouldn't it at least idle like crap?
 

TC93

Well-Known Member
Sep 11, 2000
2,075
1
57
Ellerslie GA 31807
Apr 13, 2004
#17
  • Apr 13, 2004
  • #17
The ground should be on the driver side head on the rear. It's a pain to get to with the upper intake on, but it will be part of the injector harness.

As for the TPS, I was just refering to it to make sure it has the correct voltage & not setting it.
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 13, 2004
#18
  • Apr 13, 2004
  • #18
Hey man, I read you wrong.
My TPS ground reading was 4.9. The other wire, (green is it? I can't remember anymore) was only .04 when it should be .97 or so. THIS is where people told me that as long as it idles fine then I should leave it alone. Do you agree with that?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Apr 14, 2004
#19
  • Apr 14, 2004
  • #19
The ground wire in the injector harness is for the O2 sensors. The injectors have constant +12 supplied to them by the ECC relay. The computer supplies the ground for each injector to make it turn on.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif
 

Ozz

I think I have a problem here.
Founding Member
Jul 27, 2001
3,514
66
109
Canton, MI
Apr 14, 2004
#20
  • Apr 14, 2004
  • #20
Set my TPS to .97 this morning. Still no luck.

My mechanic friend came over and we tried pulling codes, but the comptuer is not readable. Any ideas now?
 
  • 1
  • 2
  • 3
  • 4
Next
1 of 4 Next Last
You must log in or register to reply here.

Similar threads

B
Electrical Why does my fox body keep frying eecs
  • brandyn200
  • Jun 20, 2026
  • Fox 5.0 Mustang Tech
Replies
8
Views
258
Fox 5.0 Mustang Tech Jun 25, 2026
AeroCoupe
Engine Fuel not pumping
  • Creomod
  • Apr 13, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
51
Views
1K
Fox 5.0 Mustang Tech Wednesday at 8:31 PM
Noobz347
S
Need help asap
  • shaggyman65
  • Dec 24, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
257
1996 - 2004 SN95 Mustang -General/Talk- Dec 24, 2025
shaggyman65
S
L
Engine Why won't the motor start if I have spark and fuel
  • LeviAnderson
  • Nov 20, 2025
  • Fox 5.0 Mustang Tech
Replies
3
Views
422
Fox 5.0 Mustang Tech Nov 20, 2025
AeroCoupe
Problems after exhaust install and 02 harness
  • djj62478
  • Jul 2, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
39
Views
545
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jul 18, 2026
AeroCoupe
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?