no spark.... HELP.... expert advice needed

[coldshard]

ok, here's the deal...... i was driving home doing 30mph in third gear and i down shift to make a turn after the turn i accelerate and at 3000rpm my tach starts jumping between 1000 and 4500rpms, so i pull over and let it idle for a min, it sounds fine now, i give it a little gas and at 3000rpms it starts jumping and stuttering again, i check under the hood for weird leaks and loose wires.... nada..... so i get in and limp it home at 2500rpms, i shut it off and let it sit for about 15 mins while i curse and moan, i go back out and start it up and about a min later it just dies and wouldn't start again........ now to the trouble shooting...... i went ahead and changed my fuel filter, plugs, and plug wires, still no start checked the fuel pump it was fine, but the fuel control relay was a little flaky when i ohmed it so i replaced it..... still no start..... then i got smart and pulled off a plug wire and looked for spark,('cause i am getting fuel) no spark..... new wires and they ohm good so that wasn't it, checked the coil and it ohmed good too, so no prob there....... what am i missing? my buddy said it might be my ecu but i don't wanna put another one in and maybe dork that one up (its my buddy's ecu, don't wanna have to get him a new one too), so what else should i check before the ecu swap could there be something i missed...... HELP........

 

[DevilSperm]

when you checked your coil did you also check the power transistor? do that....the next thing i would check is the MPI fuse....then id swap ecus and see if that helps

 

[coldshard]

checked the CAS, it checked fine injectors are firing but no spark, i'll check the power transistor but i can't find the MPI fuse...... ( haynes manuals........ no real help at all) :thumbdown

 

[DevilSperm]

90 and 91 mpi fuse is on the battery cable right where it hooks to the battery...should be 3 fuses there unless they changed it

 

[gsxtacy]

Also check and see that the harness connector by the fuel rail is connected. I had a instance much like the one you described, I revved the car up and all of a sudden it died.

Found out the harness hit the front strut tower brace and came unplugged. Plugged it back in and it cranked up and ran fine.

I don't know what that plug is but it had something to do with the coils firing.

good luck.

gsxtacy

 

[steve]

I think DevilSperm is right on about the PTM, the tach signal is generated at the power transistor module and if it's bad you never fire the coils. The coils and the PTM both get power from the ignition switch run position, not the MPI relay so the next place would be to look for power at pin 3 on the coil or pin 6 of the PTM and the ECU's next to check.

Steve

 

[coldshard]

ok checked the mpi fuse(don't know why i didn't see it before, under the fuse cap labeled mpi...... duh) its good checked the ignition power transistor, it checked bad according to the haynes manual so i took it to my friend's house and put it in his car just to make sure and it fired up just fine, i borrowed his ecu and put it in my car and still no start....... what am i missing, i've checked everything i can think of and everything haynes can think of, is there anything else i can do(short of having it towed to the devil and spending a small fortune) this is killing me i can't drive my baby and i know she's getting irritated

 

[steve]

Did you check to make sure you had power to the coil and PTM in your car?
Those aren't powered by the MPI thay are powered off the ignition switch.

Did you try your ECU in his car just to eliminate it.

The factory manuals test procedure for the PTM has errors in it. Haynes may have copied the errors. I can't think of a better test than what you did, run it in another car

Steve

 

[coldshard]

ok.... aperently i was testin the CAS wrong i tried to turn her over today and she fired up.... and then died about a min later :thumbdown ... but when i tried again i got a CEL (finally) so i read the code.... CAS malfunction..... i'm gonna try to get my friend to let me borrow his to see if i get the same thing..... but at nearly $400 i hope i've found it.... i'll keep posting until the prob is fixed so everyone else can learn from my stupidity.... hopefully the CAS is the prob then my baby will love me again and get me 1\4 mile ahead of all those punk hondas once again......... thanks to everyone who posted to try to help me(i feel like such a moron sometimes) i appreciate all the input...... with friends like you i feel even better when i kill a honda at the track

 

[hellahfresh]

same thing for my car too 96 RS no spark? so whats wrong with my car? I bought another ecu and still no spark..?? So what should i do now? I changed the crank sensor, oil pump and many other little things and still no Spark to the coils. let me nkow too!

 

[coldshard]

yep it was the CAS..... one of the terminals inside it was completely melted...... got a used one off a galant VR-4 and bang ....... purring like a kitten... thanks once again to everyone that gave input ......

 

[steve]

Thanks for reporting back with the solution. Sorry we sent you off chasing in the wrong direction.

Steve

 

[squee]

I have a no start problem as well. It was daylight when i looked but still I dont believe i am getting any spark. I replaced the coil pack and no luck, checked the fuses and they all looked good. What is CAS? The situation is this: I drove it home it ran fine, I parked it and the next morning it wasnt starting. It makes a horrible sound when I turn the key and attempt to start it, when I turn the key to the ignition position is makes a grinding sound then if I the key to the off position the sound remains for a couple seconds. its a spinning grinding sound. The sound seems like its comming from near or underneath my intake manifold. With my honda , if the starter goes out it doesnt make anysound or attempt to turn, so Im not sure if thats what it could be or not. Is there a way to test to see if its the starter, or does this sound like it probably is my starter? its a 90 tsi . thanks guys

 

[coldshard]

does the motor turn over at all? if not the starter motor or solinoid may be bad. if it does turn over..... check the CAS (cam angle sensor) located on the upper left on the side of the valve cover, open it up and check the sensor (since yours is an optical type you need to remove the two small screws holding the sensor in place) if it looks melted or burned its bad, but that's not always visibly present in a bad CAS..... the next thing to check is your power transistor located just underneath your coil pack toward the driver side (it looks like a little green wafer with a plug thats nearly the same size going into it) ...... check coil pack plugs and plug wires just to be sure you didn't miss something simple....... if all else fails it may be your ECU (better hope not)...... good luck

 

[Talont92]

I was driving my car home one day and i herd a knock in the motor and later found
out that it was a rod that came loose. So i go ahead and pull my engine out and
rebuild it but now the car dosent fire i dont know if cam sensor needs to be timed or
what happend because i dont think the coil or anything esle would go bad just by sitting there. Its a 98 Gst