Ive currently picked up a 91 gt 5.0 stang well its been sitting for a couple years and im just stumped on whats wrong with it. heres what ive done etc. well i wasnt getting any spark at the plugs the then i checked the spark off the coil and nothing until i stop cranking i get two sparks after i stop cranking. so i replace the coil still doing same thing now i look at other things buddy says change the tfi so do that same situation. well ive been talking around to a few people a couple solutions. its grounding out somewhere in the harness( from what i can tell everything looks to be intact). checked all the connections all the way to the ecm connections no buildup etc. ignition switch is working because all other stuff it operates is comminng on. no heres the main question. i was told about the ignition suppression resistor Could this be the problem? i hooked a ohm meter up to it checking for resistance its getting power too and from what i can tell its not putting anything out. Ive had a couple stangs before this on and this is first ive had with this problem. any help could be appreciated. also does anyone know what the part number is or where i go about purchasing one ive went to all the local parts stores (autozone and advanced useless, napa, car quest, and the dealor.
ignition problem?
- Thread starter bknauss71
- Start date
The ignition suppressor is for noise. It's just a little grounded cap.
Do you have a CCD or push-start TFI? Each will bolt into the other's dizzy but the car will run like crap if the wrong one is used. Confirm this and then check the pin-out for your particular unit. See the following diagram. If you have a TFI with a 'start signal in', see if that terminal receives 12 volts while cranking. If not, that is very likely your issue.
Thanks to S&2B's (site host) and Tom Moss (schematic author).
The following shows the ignition switch. White/pink is the crank circuit. You can see where it splits off to go to the TFI module.
Thanks to S&2B's (site host) and Tom Moss (schematic author).
Good luck.
Do you have a CCD or push-start TFI? Each will bolt into the other's dizzy but the car will run like crap if the wrong one is used. Confirm this and then check the pin-out for your particular unit. See the following diagram. If you have a TFI with a 'start signal in', see if that terminal receives 12 volts while cranking. If not, that is very likely your issue.
Thanks to S&2B's (site host) and Tom Moss (schematic author).
The following shows the ignition switch. White/pink is the crank circuit. You can see where it splits off to go to the TFI module.
Thanks to S&2B's (site host) and Tom Moss (schematic author).
Good luck.
well i guess that makes since from its name. ill go check the ignition out its the second tfi its correct and installed correctly. if ignition checks out must either be the stator in the distirbutor inwhich have to buy another distributor. well thx for the diagrams its just odd how it throws two sparks out after i let ignition off.
well i checked what you were saying without being cranked its at 12.5ish area well when i crank it hangs down around 9.8-9.6. well i have a buddy that runs a junkyard had a 5.0 in their that ran so i snagged the distributor and same situation. at that point what should i do? i know alot about cars but nothing pertaining to this situation on this vehicle. again list of what ive changed now
coil pack
tfi
distributor
checked all the connections i know that affect its spark situation
ignition switch i assume is operating correctly accesories etc. come on.
i cant find any wiring for an alarm etc. that had been on the vehicle ( ive had one in the past wouldnt start because of alarm crap)
is their a crank sensor on this vechicle or is that basically the tfi.
all i know is the car has been sitting for approx 18 months.
again as soon as i let off the ignition switch i get spark could this be causing a short? also before i checked the coil for when im cranking its bogs down alot too but i just assumed that would happen considering its drawing power all this is done off battery charger.
coil pack
tfi
distributor
checked all the connections i know that affect its spark situation
ignition switch i assume is operating correctly accesories etc. come on.
i cant find any wiring for an alarm etc. that had been on the vehicle ( ive had one in the past wouldnt start because of alarm crap)
is their a crank sensor on this vechicle or is that basically the tfi.
all i know is the car has been sitting for approx 18 months.
again as soon as i let off the ignition switch i get spark could this be causing a short? also before i checked the coil for when im cranking its bogs down alot too but i just assumed that would happen considering its drawing power all this is done off battery charger.
The crank signal wire should not show battery voltage with the key off. If it did you should have an issue with the starter running with the key off.
The cranking value of ~10 volts is ok but get a charger on the battery because it's getting discharged, which doesnt help anything. You need a blue spark to start a car.
We dont have a crank or cam sensor but rather a PIP inside the dizzy.
The cranking value of ~10 volts is ok but get a charger on the battery because it's getting discharged, which doesnt help anything. You need a blue spark to start a car.
We dont have a crank or cam sensor but rather a PIP inside the dizzy.
well now my hands are in the air! I cleaned all the ground i could find made sure it was getting a good ground. still same situation but have few other pieces of info. i dont even have to engage the starter just turn the switch almost to where it would trigger starter and coil get spark but when you go to crank you get no spark when letting off the switch you get spark. i almost bet if the car were a stick i could push start it by what its doing. again ive replaced everything on the ignition besides the switch. i figured switch was working due to it operating accesories but any other ideas would be greatly appreicated.
Have you checked for power at the coil while cranking? It receives constant accessory 12 volts, and the ground is pulsed. If your coil power is missing (tested at the coil's electrical connector), check other VPWR branches to see if they're also affected. If you dont have VPWR, that can be an ignition switch issue.