Help - '95 ATX - No Fire

[slapnpop]

So, the '95 ATX went dead Friday afternoon. Like someone hit a **** switch, engine just stops. All other electronics are working fine, and the fuel rail is pressurizing. I got no spark.

Tried to pull codes, but get a 1 1 1 in Key on Engine off, but can't start the engine to run full codes. Come back an hour later, and she starts, so I run the full codes and don't get anything concerning (only EGR valve failed to respond, I need to clean the intake).

I figure the CPS is due, so I install one Saturday morning. Car starts up and runs fine. I figure problem solved.

Then comes this afternoon (Tuesday), and I get a call that the car died again on the wife's way home from work. Same deal, KOEO yeilds a 1 1 1. This time waiting doesn't get a restart, so I have her towed home.

I've looked over all the connections I touched, and it's all good. I assume now that the problem was not the CPS, but something else. Any way to tell without the engine running? I don't want to just start replacing things on a whim.

 

[projectSHO89]

Might be one of several things, however, I'd be checking fuel pressure first.

Steve

 

[slapnpop]

Can't check the pressure at the moment, will try to do that tomorrow. Failure is light switch like, leading me to believe electrical.

I do know the fuel pump is on and running, and the rail does pressurize enough to squirt fuel up to the hood.

 

[Storm-Chaser]

Watch what the tach does when the car dies - also the battery light. The problem may be computer related, since it's failing to store codes (ie. loss of the B+ power-source to the computer).

 

[slapnpop]

Update this morning: Still only showing 111, and will not start. Getting tach signal when motor is turning with the starter, so this means CPS good, right?

Will try to test fuel pressure soon.

 

[slapnpop]

Update this afternoon: Fuel rail has pressure. Changed cam sensor, no improvement.

Any other suggestions on what to check or how to test?

 

[Kens1992mtxSHO]

Dis??

 

[hawkeye18]

Check the terminals. Does everything completely die when you try to start it? Like, lights, dash, everything? If it does, chances are good that a loose/corroded terminal is not allowing enough current through to start it, but it is allowing enough current through to run the small(er) electronics.

I had this happen to me a couple of times when terminals cracked. They looked ok from more than 3 inches away, and it would get to KOEO just fine, but as soon as I tried to start it, it just flopped on the ground and played possum.

So, again; check your battery terminals very carefully, especially if they're stock.

 

[slapnpop]

Battery and terminals are brand new, just installed Saturday when I was doing the 1st CPS.

Tried to test using This Procedure. During testing, ONCE, and only for a second, the LED test light light started flashing, and she coughed a second, then right back to dead. Otherwise I just see a constant light. I am getting 12V between the V+ and V- pins of the CPS, but no pulsing of the output signal to the EEC. With the multimeter, I am seeing battery voltage on the PIP out with key on, dropping down to 7-9v with crank.

To Recap:

Tach works when cranking, but CEL does not go out. I have so far changed out the CPS and CID.

 

[Storm-Chaser]

How are you testing fuel pressure ? Simply getting a fuel-spray that hits the hood-mat is not sufficient - you need to get a gauge on the rail and check the actual pressure.

Also, "where" in the testing procedure did you failed to get the proper results? Focus on those harness-leads where you're not getting proper voltage and/or the intermittent output.

Battery and terminals are brand new, just installed Saturday when I was doing the 1st CPS.

Tried to test using This Procedure. During testing, ONCE, and only for a second, the LED test light light started flashing, and she coughed a second, then right back to dead. Otherwise I just see a constant light. I am getting 12V between the V+ and V- pins of the CPS, but no pulsing of the output signal to the EEC. With the multimeter, I am seeing battery voltage on the PIP out with key on, dropping down to 7-9v with crank.

To Recap:

Tach works when cranking, but CEL does not go out. I have so far changed out the CPS and CID.

 

[Phoenix]

1-Spray some brake cleaner in the TB while someone starts it , if it starts , or wants to , you need a fuel pump.

2-Make sure the DIS has ALL its 4 bolts. 3 bolts = no start.

3-Make sure the ground strap wire is connected (behind the intake to the firewall)

 

[slapnpop]

How are you testing fuel pressure ? Simply getting a fuel-spray that hits the hood-mat is not sufficient - you need to get a gauge on the rail and check the actual pressure.

Also, "where" in the testing procedure did you failed to get the proper results? Focus on those harness-leads where you're not getting proper voltage and/or the intermittent output.

Fuel rail is getting 40 PSI of pressure, and I watched the regulator kick in on the gauge.

The DIS module/intake are properly grounded. DIS ground pin shows 1.2 ohms to negative battery terminal.

My troubles trying to use the rangerj test method started at the CPS. I honestly think I'm doing something wrong when trying to troubleshoot the electrical system. On the CPS plug, with the lock facing up, the lower two pins are the power and ground, correct? The top two pins are the output, one to the EEC and one to the DIS, correct? What should the supply voltage be on the bottom two pins? Am I correct in understanding that I should see either 0 or 5 volts from the CPS with key on engine off (depending on whether or not a vein is in the sensor)? And that once I crank, I should see this signal pulse with the veins turning? Are the two output signals the same?

I also tried referencing this procedure, but I think it may be causing me more confusion that help. The diagram of the CPS plug is backwards from my wiring harness, if the note about "Connections are shown looking into the wiring harness" is correct. The CPS connector diagram in the link matches my sensor, not my wiring harness.