Fairly new to working on my Mustang.

[cleck673]

If anyone can help, My 86 5.0 died at work 2 weeks ago, College has been so busy that I have not had a chance to fix it or tow it home. My company (a phone company in the south) might be striking starting at midnight on Saturday, so I have to get it out of there tommorow.

What's Wrong?

Symptoms:
Turns over, fires up.... then immediately dies. It is like some sensor is shutting it down. I have not check anything. (don't really know much at all about it yet....) I went ahead and bought one that I posted about here:
http://sectalk.com/86gt.html

Got it for 2k and all worked fine. I let it sit for a month, waiting for cash to start restoring. I decided to drive it to work, Cranked right up.... as I went up the driveway, it stalled once. Cranked right back up, so I thought nothing of it. Drove fine all the way to work. Parked. Got done, BAM... here we sit.

Any suggestions or feedback? TIA

 

[T_5.0_N'works]

Fuel filter, pump?

 

[v8only]

do you hear the fuel pump prime when you turn the key to on?? I agree, it may be fuel pump related, or the relay, or even the ignition switch.

 

[cleck673]

I did not listen for it... I will tommorow.

It sounds like it is getting fuel... As it revs if I gas it while cranking, but then it stalls out immediately. Vrrrrroo----MMMmmm,,,,,

 

[v8only]

for now, just listen for that fuel pump whir when you turn the key, that will at least tell you whether or not to start with the fuel system.

 

[90mustangGT]

Your probally getting fuel pressure but not the flow. The fuel pump is strong enough to prime to get enought to crank but cant keep it going. Get a fuel pressure gauge and check. You'll need it again durring further modding.

When you get a fuel pump, at least go with a 190lph or better yet, 255lph.

 

[hllon4whls]

Try to give it a little gas when it cranks. If you can get it to warm up, it may stay running. If this is the case, it is the IAC.

Bellsouth will not strike. The contract will be signed. I have faith. You must be craft and not management. What do you do and where?

 

[cleck673]

I am an ET in Tuscaloosa,AL

 

[cleck673]

Thanks. I will try that

 

[shttygtstang]

what abought the box in the trunk for the fuel pump mine did that when i got on it realy hard one time switch the gray box it might be off

 

[cleck673]

Check the inertia switch, it was good. I can not hear the pump, but I am not exactly in a quiet place and I have no helper.

ONe thing that may help, I am able to rev the engine as it is trying to crank, but as soon as I let off the key, it dies. When the starter is engaged, does the fuel pump get power? When I let off, removing power and relying on the electronics to keep it running?

Thanks!

 

[HISSIN50]

you could also try cycling the key a few times to help build pressure, before you try to start.

i like the FP gauge idea as well. 40 bucks or so at a parts store and worth it in the future.
you could also try spraying a smidge of starting fluid in the TB and see if it tries to catch and run for a second. that would (IMHO) confirm that the fuel system/management is the issue.
good luck.

 

[cleck673]

OK, bought a fuel guage. Plugged it in on a connector on the fuel rail. The guage is 0-100 PSI (something else in the middle). When I pumped the gas and tried to start, it went to 25PSI.

I also replaced the fuel filter too.

 

[HISSIN50]

is your 86 SD? i think they are....if so, the FP should be more like 36-39 PSI with no vac line attached to the FPR (IIRC, check the book to be sure on that pressure).

if you have low pressure, i would look at a bad FP or regulator. you can try to block the return line, so you can see how much pressure the pump is putting out (this is also a test for the check valve in the pump).

check the regulator for fuel in the vac line that attaches to it (a sign of a bad regulator diaphram).

now if you dont have SD, then dont follow this advice. good luck.

 

[cleck673]

SD?

 

[HISSIN50]

SD = speed density. i think the older injection was CFI. i think you should be SD though. (but im not sure).

 

[cleck673]

How can I tell?

Also, I took off all the things attached to the throttle body. (See Pic)

The top part was real nasty inside. I used throttle cleaner and sorta cleaned it, but it is still quite filthy.

 

[HISSIN50]

looks like a SD set up. the top arrow looks like it is pointing to the EGR and the lower arrow is the IAC/IAB (idle air controller or bypass - same thing).

it sounds to me like you are missing some Fuel pressure. have you tried to cycle the key a few times to see what the pressure reads (to see if it builds)?

try to test the pressure with the vac line off the regulator and at idle.
good luck.

 

[MadMatt5oh]

Damn, you are SD. Youre pointing at the EGR and the IAC sensor. It sounds like you have a fuel issue. Do you smell gas on the repeated attempts to start?

 

[cleck673]

Thanks. I will try that tommorow. SD.... Is this a good thing or bad thing. Sorry that I am this ignorant. I had a 90 LX 5.0 in 93-94 timeframe, but It never gave me a ounce of trouble and I learned nothing of it.