98 Cobra won't start

[dromeda]

Alright this is bugging me, I haven't been able to drive her for a month now

She cranks just fine but never catches. I've checked the fuel pressure and it's fine, I can also hear the pump prime when I turn the ignition to on.

So then I pulled a plug to check the spark, nothing. Checked a couple, all nothing. So it's getting fuel but no spark.

I've searched these forums a thousand times and saw people had this problem and it's their PATS. I have three keys, one of which I know is bad. I try the two good keys and the theft light lights up normal for about 3 seconds and then turns off. I try the bad key and it starts blinking, which it should. So I hit the disarm button on my remote and try the good key and the theft light functions normally. This sounds like it's reading the key code just fine.

I've checked fuses, actually found one blown, replaced it but didn't help. Tried the disconnect battery for 10 minutes thing, nothing. Any other suggestions?

Thanks

 

[1LowGT]

if you have a good key and still dont fire maybe check into the crank trigger sensor on the front of the engine

 

[Roger_4.6_96]

Replace your coilpacks and anything else spark related.

 

[dromeda]

if you have a good key and still dont fire maybe check into the crank trigger sensor on the front of the engine

I'll check it, but my understanding is the car goes into dumb mode if that sensor goes out and should still start.

Replace your coilpacks and anything else spark related.

Unfortunately, everything else spark related is the Ignition Control Module, PCM, and PATS module . I've tested the coilpacks and according to my Haynes manuel, they appear to be good.

I'll check to make sure the coilpacks are actually getting a signal.

Thanks for the suggestions, anyone else?

 

[billfisher]

go back to basics dude. pull the plugs to the coil packs. crank the motor and look for signal with a light. go to each terminal on each bank. if there is no signal look to the crank sensor. the signal will appear to be an analog 0-13v with a dead spot every cycle. the chances both coil packs and plugs are bad is remote, unless surge got them. also check the TDC #1 signal on the drivers side cam cover. you should get signal every two cycles. if the computer does not know where TDC or crank position is it will not fire. my guess is not the key sensor. i suspect the cam TDC sensor or wiring. if you have all these signals the computer has to trigger spark, even if it is timed wrong. send it to dealer for reprogramming of keys/disable of security. make sure to check continuity to computer on the passenger firewall.

 

[dromeda]

Just in case someone searches this thread, they'll find my answer.

The last thing I did was take out the cam shaft sensor (which checked out fine), clean it and then stick it back in. Wouldn't start. Waited a week and tried to start it again, started right up. Not sure what that means, but I haven't had the problem since.

 

[98Black4.6]

Alright this is bugging me, I haven't been able to drive her for a month now

She cranks just fine but never catches. I've checked the fuel pressure and it's fine, I can also hear the pump prime when I turn the ignition to on.

So then I pulled a plug to check the spark, nothing. Checked a couple, all nothing. So it's getting fuel but no spark.

I've searched these forums a thousand times and saw people had this problem and it's their PATS. I have three keys, one of which I know is bad. I try the two good keys and the theft light lights up normal for about 3 seconds and then turns off. I try the bad key and it starts blinking, which it should. So I hit the disarm button on my remote and try the good key and the theft light functions normally. This sounds like it's reading the key code just fine.

I've checked fuses, actually found one blown, replaced it but didn't help. Tried the disconnect battery for 10 minutes thing, nothing. Any other suggestions?

Thanks

I had to end up having my PATS system replaced. I had the same problems as you did. $75 for the part, $200 for labor at Ford. No one else can replace it unless you know how to do it yourself.

 

[dromeda]

Alright, the problem is back. It's not PATS as I can sometimes get it to start (I love those intermitten problems ).

Last time I got it to start I jiggled the maf sensor plug. Though I don't think that's it. It's still getting no spark. If I try it and it doesn't start, I usually try it a bunch more times, wait and week and then try it and it starts right up. I've checked all the usuals, doesn't make since...

PLEASE help! I'm afraid to drive it anywhere for fear it won't start once I get there. It's never stopped once it's started.

 

[deftsound]

this is maybe far fetched but could it be a bad ground???

 

[billfisher]

have you checked all of the sensors?

i detailed above some steps to verify problem.

broken wires from vibration happen all the time in my business. there is a bunch of pinch point in the cars.

the harness runs between the block and mounts onboth sides. plenty of places to cut.

you are going to have to spark chase it.

crank,cam,coil packs,computer that's all there is.

 

[back_in_black]

Maybe you have already done this, I didn't know about it, Have you tried pushing the gas pedal to the floor when cranking it. This cuts off the fuel, and it might start right up. Mine does this every once and a while and it is in my tune, I need to go in and have my cold start parameters fixed so it isn't as rich on cold starts. Ok, I just noticed the "not getting spark phrase", ignore.....

 

[deftsound]

i think its bad ground or connection, that would explain why its intermittent

 

[dromeda]

For those searching the threads, for the resolution see:

http://forums.stangnet.com/showthread.php?t=672268#top