just replaced the CPS and the CAS. car still wont fire. why the hell did my shit just stop working without any kind of warning or anything?

no spark to plugs. have tried/inspected:
coil swapped out
plug wires have correct resistance
harness inspected
new CAS and CPS
MSD ignition bypassed back to stock firing sytem
all sensors are plugged
getting correct power to various sensor plugs

What the hell? car turns over but wont fire. it turns over 6-8 times and then "hiccups". i assume its from the compression build up without the spark....

would a fried ECU cause this? would everything else still "work" and have no codes if ECU went tits up?

You also have the 4 wires reconnected on the main bypass harness of the MSD.

Originally posted by DJ420a
You also have the 4 wires reconnected on the main bypass harness of the MSD.

yes, everything is plugged in just as it was on the day it died.

Do you have an alarm? Ignition kill? checked the engine fusible links?
pee'd on it?

Originally posted by djtrickee
Do you have an alarm? Ignition kill? checked the engine fusible links? pee'd on it?

tried unplugging the alarm. there is no manual kill switch. all engine fuses are good. peeing on it is after i try the ECU.

Originally posted by tim97rs

Originally posted by djtrickee Do you have an alarm? Ignition kill? checked the engine fusible links? pee'd on it?

tried unplugging the alarm. there is no manual kill switch. all engine fuses are good. peeing on it is after i try the ECU.

what kind of alarm. if is shorted out in the armed state it could still be killing the ignition. unhooking or even yanking the brain might not solve that. pee on the positive battery terminal while holding the frame of the car to see if it has the correct "stream voltage"

Originally posted by djtrickee

Originally posted by tim97rs

Originally posted by djtrickee Do you have an alarm? Ignition kill? checked the engine fusible links? pee'd on it?

tried unplugging the alarm. there is no manual kill switch. all engine fuses are good. peeing on it is after i try the ECU.

what kind of alarm. if is shorted out in the armed state it could still be killing the ignition. unhooking or even yanking the brain might not solve that. pee on the positive battery terminal while holding the frame of the car to see if it has the correct "stream voltage"

If it is an alarm malfucntion the car won't even turn over. Alarms kill the power to the starter, not to the ignition system.

i know this is going to sound weird but the speed sensor has somthing in common with the crank sensor and when battery acid drips onto it it causes it to short and the crank sensor doesnt work properly so sometimes u can just unplug it and the car will work
this comes from a friend thats a mits technician and he said this happens alot
also not real sure if u just got done with a rebuild or something but make sure u dont have any plugs mixed up the coil pack plug is the same as a couple others near by

Originally posted by 2g99RSNC
i know this is going to sound weird but the speed sensor has somthing in common with the crank sensor and when battery acid drips onto it it causes it to short and the crank sensor doesnt work properly so sometimes u can just unplug it and the car will work this comes from a friend thats a mits technician and he said this happens alot also not real sure if u just got done with a rebuild or something but make sure u dont have any plugs mixed up the coil pack plug is the same as a couple others near by

They share the same 9v power supply circuit, so if the VSS shorts, then other sensors on that circuit don't get power.

Originally posted by a_miller_76

Originally posted by djtrickee

Originally posted by tim97rs

Originally posted by djtrickee Do you have an alarm? Ignition kill? checked the engine fusible links? pee'd on it?

tried unplugging the alarm. there is no manual kill switch. all engine fuses are good. peeing on it is after i try the ECU.

what kind of alarm. if is shorted out in the armed state it could still be killing the ignition. unhooking or even yanking the brain might not solve that. pee on the positive battery terminal while holding the frame of the car to see if it has the correct "stream voltage"

If it is an alarm malfucntion the car won't even turn over. Alarms kill the power to the starter, not to the ignition system.

Not all. Mine kills both.

Not for nothing, but even in by-pass mode the ignition interupt (brown wire) on the msd still works. Check to see its not grounded out or if its hooked up a switch it didn't malfunction. Also how did you make the connection at the coil with the msd wires? check to see the soilder/plug crimps held.

i have a compustar alarm system. its not stuck in alarm mode either. its functions are all programmed into the brain with a programming box and my installer friend siad he didn't program any kill options. the only thing i did with it at the time it stopped working was to let the built in TT count down, then.... wammo. no spark!!! ????????

its not the MSD. i called thier tech dept.and they said that if it was bade it just woud not work at all. i am getting the LED indicator as per normal operation, and its has woked fine for over a year with the current wiring job...so i can't see it being related to the MSD... but then again...i have had my share of "Doh!!!" moments.
keep the ideas comin..

thanx

You might want to check the fuse that say's MOTOR. Its in the fuse block under the hood. Pull it out Tcompletely *its a bitch since it bolted in*. hey cost like 20$ to replace from napa/schucks. The dealer is about 50$. If it is not that then its the ECU. I dont' know if they have a dealer down there, but you could pull it and have them check it ???? mabey.

Originally posted by tim97rs
the only thing i did with it at the time it stopped working was to let the built in TT count down, then.... wammo. no spark!!!

Is that from the compustar system? To me it seems this may be part of the problem. If it shut the motor down, and now it won't start, then I dunno, it's just my shot in the dark...

nothing will work if the ecu if fried. mine went up on smoke and EVERYTHING died. you could have a short. I inspected all my wires after frying it and found nothing, Had a friend who wires fighter jets come and help and he found a small bare spot in my oil sending unit wire. Check, re-check and check again, annoying yes, but effective non the less.

There are thousands of ways in which kill an ECU, many of which would probably cause a no-spark situation.

I would still rule out wiring first, though, checking the harness to the speed sensor for continuity and resistance (from the ECU harness connnector to the sensor harness connector), and doing the same with the cam sensor, crank sensor, and coil pack.

The big f'n motor fuse is also a good suggestion.

I think the ECU is Toast. When I helped my buddy swap in his 2.4 the coil harness and the speed sensor harness got swapped and it killed the ECU. We had the exact same symptoms as you, everything worked except the motor would not spark (had fuel, accessories would power on etc..). He took the ECU into Carquest (Its a parts store, not shure if you have these in the states) and they checked it out and had it rebuilt. As soon as the new ecu went in it fired up no problem. If you have checked everything else I would say change the ECU.

asd relay
or fuel pump relay

Originally posted by mcgyvr
asd relay or fuel pump relay

Dude that's what you say in every thread. His fuel pump relay isn't going to cause him to not get spark.

Originally posted by a_miller_76

Originally posted by mcgyvr asd relay or fuel pump relay

Dude that's what you say in every thread. His fuel pump relay isn't going to cause him to not get spark.

...and if it were the ASD relay, he wouldn't have 12v at the coil.

Originally posted by DarkOne

Originally posted by a_miller_76

Originally posted by mcgyvr asd relay or fuel pump relay

Dude that's what you say in every thread. His fuel pump relay isn't going to cause him to not get spark.

...and if it were the ASD relay, he wouldn't have 12v at the coil.

I say ASD relay cause thats what the problem is ALOT of times.
and if this were all true

""no spark to plugs. have tried/inspected:
coil swapped out
plug wires have correct resistance
harness inspected
new CAS and CPS
MSD ignition bypassed back to stock firing sytem
all sensors are plugged
getting correct power to various sensor plugs""

then there is no reason he shouldn't have spark, besides the asd relay and the ECU

swapped out ASD realy as well, still no spark. waiting on an ECU now...

I had the exact same problem Tim. The pigtail on the crank position sensor, although plugged in, wasn't making good enough contact with the probes on the the sensor.

Longshot, but you could check that.

Tony