cid cps...

[ty91sho]

1991 3.0l plus,,
one question i cant seem to find is, does the cid have anything to do with spark?
iam just wondering because i dont have any spark. and from what i learned the cid has to do with the fuel timing as in when to put it in with the valve train, not spark. is this correct? so i would guess its my cps?
my problem is over the past month or so i have had some hard starting situations. what i think to be classic cps failure. but my father thinks it might be the cid. i still have rpm when its cranking, i get NO codes that come up. my check engine light stays on while cranking. no spark. fuel pump primes. all it does is cranks. then i could go out there and it will start no problem. its a really hit an miss thing. and also does anyone know the part number for the cps. i found the cid is (wells f134) but cant seem to find the part# for the cps. thanks tyler

 

[ty91sho]

whoops i found the cps part number now. its called a du-47 stator. E9SZ-12A112-A. correct me if iam wrong. thanks

 

[Toolman]

A failing CID will also cause very poor running at times, causing you to have to **** the engine and try to restart. But even with the CID unplugged, you will still have spark, so your issue seems to point to something else.

 

[gmorrell]

During cranking, the ECU uses the CID for fuel injector synchronization, and the DIS module uses the CID for ignition synchronization. Once the engine is running, you can unplug the CID and the engine will continue to run. The ECU monitors the CID and will set the CEL and store a code if the CID goes away.

If the CID isn't seen during cranking, both the ECU and the DIS have strategies to try different injector and ignition sync-ups during cranking. Each time the ignition is cycled off-on-crank-run, they will try a different starting sequence to attempt to start the engine.

CPS failure often manifests as hard starting when hot, or outright failure when the engine is hot. A bad CPS will often work fine on a cold engine, and fail when it warms up.

If the CPS isn't working, the ECU doesn't know the crank is turning and the following won't happen:
1. ECU will not re-start the fuel pump during cranking.
2. ECU will not fire the fuel injectors.
3. DIS will not fire the ignition.

The CPS has two outputs, one feeds the ECU, the other feeds the DIS. It's possible that the ECU output is working and telling EEC to restart the fuel pump and fire the injectors, but the DIS output is not telling the DIS to fire the plugs.

HOWEVER... If you have RPM (dash tach) during cranking, that means the DIS is firing the coils, because the tach signal (IDM) is created in the DIS module, and IDM is generated from the back EMF of the ignition coil primaries.

Don't know what your problem is, but hope this helps.

 

[ty91sho]

wow good info there.
and yes i do have rpm when cranking. but i read that sometimes that isnt a good way to tell if the cps is the bad link.is there a way to "bench test" the cps from the plugs up in the intake? so that i dont need to take front of the motor apart? i need to do some more searching i guess.
the ground strap is on the intake. all the connections are clean.

 

[Toolman]

DO you have a known good DIS to try in place of your current one?

 

[ty91sho]

no i do not. i could get one prolly from are local club. but not today, would a bad DIS make it not even putt or sputter or spark or anything though?

 

[Toolman]

Yes. But a bad coil pack could as well.

 

[Vnuk1]

Maybe you can use this to reference and try to get the voltages from the pins? Not too sure if these will help but throwing them out there anyway.

 

[ty91sho]

hey thanks, so i ordered a CPS from autozone and we will see what that does when i put her in. i figured start with the that and see what happens. 38 bucks i thought was good. so i will let you guys know

 

[sho2see]

38 is really good i got mine 2-3 weeks ago for 55.
Hope that fixes it and mind as well change your timing belt and water pump while you have everything apart.

 

[itwonder]

Before you go to the considerable trouble to change the CPS, get a 12V LED test light and probe the signals at the DIS. The fact that you have RPM indication during cranking and fuel pump prime suggests the CPS is working. See if pins 8,9, and 11 on connector C155 at the DIS show a flashing light on the test light when cranking. Those signals tell each of the 3 coils to fire. You can probe the CID signal at the DIS too.