issue with car starting

[Bolt on 5.0]

I finally bout another mustang its a 1991 GT. The only problem with it is when I crank it to start it will only start when I release they key. Otherwise it will just keep cranking. I will look more into it but was wondering if anyne had dealt with this specific problem.

Also where can I get a good wireing diagram book, the haynes amnual I have is a joke I can barely read the print

John

 

[JBeezy53]

Time to update your sig.

 

[Bolt on 5.0]

sig updated lol, Ill check back later, hope others have had this problem fixed.

 

[HISSIN50]

What color TFI do you have? IIRC there is a start signal terminal on grey ones and something might be bad with that connection.

Good luck.

 

[jrichker]

The diagram shows what Hissin50's describing -
notice the red wire that says TFI module just
above the EEC relay


Diagrams 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 http://www.veryuseful.com/mustang/tech/engine/

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

Diagram courtesy of Tmoss & Stang&2birds

 

[Bolt on 5.0]

yeh the ignition module is grey on my car. I was looking at a diagram on the forums here and saw that the module has a starter signal ground, maybe this is my problem. I want to check the resistance in that ground wire. I was just going to throw in a ignition switch being it is cheap but I cant find a digram of the switch so I dont want to waist my money. Ill keep you guys posted I have off tomorrow Ill see what I can find out

 

[Bolt on 5.0]

also anyone know what the little conector near the ignition module is. It does not connect to the distributor.

 

[jrichker]

also anyone know what the little conector near the ignition module is. It does not connect to the distributor.

The dangling plug is the SPOUT plug. Remove it to set the base timing and put it back in to drive the car.

The TFI gets power from the starter circuit to provide extra power when you crank the engine. The ignition switch provides power for the run mode. If the engine fires off while cranking, but dies when you let the key return to the Run position, the ignition switch is suspect. Use a voltmeter to check for power at the TFI red/green wire when you have the ignition switch in the Run position. No voltage and the fuse link shown in the first diagram I posted is suspect and so is the ignition switch.

 

[Bolt on 5.0]

I appoligise for my lack of knowlege on these distriburated cars, I really no nothing but fuel injection and coil powered cars. I will check the voltage tomorrow, I am going to pull the ignition switch tomorrow, boght the tamper proof torx tonight. I'll play with that and I want to check the ignition system on the car, it had a msd ignition box, I am going to check all the connections to and from that.

 

[Bolt on 5.0]

Ok, I tested for power in run to the coil there is battery power in start and run. There is ground in run but not start position while cranking. What suplies ground to the coil in start. Also there is voltage at the rd/gr wire on the tfi in run.

The red conector wire from the msd ignition goes to the starter soliniod and so does the black. Then the main connector from the msd run to the coil, is this correct?

Just a reminder this car starts right up every time when the ignition switch is release from start to run, it just will not start while holding the switch in start

 

[Bolt on 5.0]

ok I found the problem, the ignition system was not grounding properly. Iremoved it for the time being until I get my battery relocated to the trunk and can mount the ignition system there. Thanks to all.

 

[HISSIN50]

John, glad to hear you got it figured. For future reference, mentioning in the opening post that you had an aftermarket ignition would have been helpful. We often dont read sigs real close and mention of one down there can be overlooked pretty easily. Had we known, I'm fairly certain that Jrichker (and I) would have recommended bypassing the aftermarket ignition first to see if the issue abated.

Again, glad you got it and thanks for posting the fix - it will help future searchers.

 

[jrichker]

Remember that MSD stands for May Suddenly Die...