when I turn off the car it wont start back up

[BK_CAULEY]

i can go out start up the car let it idle then drive it around a lil bit but when i turn it off it wont start back up for nothing. i have to let it sit anywhere form 30 minutes to an hour before it will start back up. what in the world would cause this?


i have a new dizzy/pip and TFI module so i know its not that. but while its running its runs fine. this is getting dumb.

 

[HISSIN50]

Does it turn over or not?

 

[Mustang5L5]

Does it click?

 

[BK_CAULEY]

yes it will turn over fine just wont fire. just spins. i start to smell gas too. ive tried holding the pedal to the floor to cut off the injectors but that doesnt help. and it just did it again. i let it sit for 15 minutes and nothing. it didnt run but a minute or two this time.

 

[HISSIN50]

Test for spark and use a noid light to test injector pulsing when it won't catch.

 

[BlownFiveLiter]

It's not uncommon to have a bad part right out of the box, when it comes to a TFI or PIP. I think JT is eluding to that with his most recent post.

 

[BK_CAULEY]

Test for spark and use a noid light to test injector pulsing when it won't catch.

the first thing i did was test for spark. i even pulled all of the plugs to check for proper gap. im definatly getting fuel. i smell it real strong and after it fires it blows all of the unburnt fuel onto my shop wall.

it doesnt blow fuel out as its running, just the fuel that gets built up while im trying to crank it during the down time.

It's not uncommon to have a bad part right out of the box, when it comes to a TFI or PIP. I think JT is eluding to that with his most recent post.

i doubt its one of those. anytime i have had trouble with a TFI or PIP module it only happened when the car was warmed up. this is happening when the car only runs for literally seconds.

 

[Mr. Rustypwnz]

pull your codes, hook up the o2's, make sure the air intake sensor is pluged up and working, check for vaccum leaks, how about timing? did you set the cam straight up? keep checking crap, and in about a week it will run better than raymonds, I fired mine up today for a second, havent ran it in a week and it purred, made me cry a little cuz I cant drive.....

 

[BK_CAULEY]

pull your codes, hook up the o2's, make sure the air intake sensor is pluged up and working, check for vaccum leaks, how about timing? did you set the cam straight up? keep checking crap, and in about a week it will run better than raymonds, I fired mine up today for a second, havent ran it in a week and it purred, made me cry a little cuz I cant drive.....

no codes present, they are hooked up now, no vaccum leaks (wouldnt cause it to not start anyways) timing is set at 10 degrees, i have a stock timing chain i can only install the cam straight up and that wouldnt cause it to not start after being ran either.

 

[Mr. Rustypwnz]

no codes present, they are hooked up now, no vaccum leaks (wouldnt cause it to not start anyways) timing is set at 10 degrees, i have a stock timing chain i can only install the cam straight up and that wouldnt cause it to not start after being ran either.

gimme the speedpro if you swapped it out with a new one...

 

[HISSIN50]

When you know it's going to do the no-start dance, I'd pull a plug before ever trying to start it (while hot). The plug should be dry. If I read you right, having the plugs foul due to leaky injectors is possible.

It starts when the motor has sat for awhile because the fuel evaporates. Simply shutting off the injectors while doing a warm-crank isnt enough to actually clear the plugs - that takes time, lots of air flow, or manual cleaning.

You can make a rig to test if your injectors leak if you want. You do have to pull them however. I'm trying to think of a simple test you could do. Something like lettting it warm up, tripping the inertia switch and letting it run till it stalls. This should remove a great deal of pressure/volume from the lines. Now see if it will start when warm (because the leaky injectors have not been able to seep as much). Or instead, safely depress the Schrader valve and drain the fuel that comes out to a container (don't just let it spray all over).

That's just what came to mind after scanning through this.

Good luck.

 

[stykthyn]

wow, I never would of thought of something like that. that's ingenious

 

[GreatWhite]

I'm having this identical problem right now. The car has spark and noids show the injectors are getting signal. After sitting for an extended period, it starts right up like it's running normal. The car is down at the shop now to get put on the computer and get checked out, because I couldn't figure it out. I'll have to mention something to him about the "leaky injector-fouling plug" theory ...

 

[jrichker]

From the cranks OK but not start checklist...

6.
E.) No start when hot - Press the throttle to the floor & try starting it if you get this far. If it starts, replace the ECT.

Usually you would get a code 21, but if the sensor is just barely inside the diagnostic check zone, you could still have problems starting and no codes.

Code 21 – ECT sensor out of range. Broken or damaged wiring, bad ECT sensor.
Note that that if the outside air temp is below 50 degrees F that the test for the
ECT can be in error.

The ECT sensor has absolutely nothing to do with the temperature gauge. They are
different animals. The ECT sensor is normally located it the RH front of the engine in
the water feed tubes for the heater.

The ACT & ECT have the same thermistor, so the table values are the same

ACT & ECT test data:

Use Pin 46 on the computer for ground for both ECT & ACT to get most accurate
readings.

Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

Pin 25 on the computer - ACT signal in. at 50 degrees F it should be 3.5 volts. It is
a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower
intake manifold, the voltage readings will be lower because of the heat transfer.

Voltages may be measured across the ECT/ACT by probing the connector from
the rear. A pair of safety pins may be helpful in doing this. Use care in doing it
so that you don't damage the wiring or connector.

Here's the table :

50 degrees F = 3.52 v
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61
212 degrees F = .47 v
230 degrees F = .36 v
248 degrees F = .28 v

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.

50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms
212 degrees F = 2.07 K ohms
230 degrees F = 1.55 K ohms
248 degrees F = 1.18 k ohms

Diagram courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds
(website host) for help on 88-95 wiring Mustang FAQ - Engine Information

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

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

 

[BK_CAULEY]

turns out my tfi module was toast.