Help! No-start. VATS Trouble? Check me on this

[TedC]

Boom made the point that you should not hear the pump run during this condition and that this may be pointing us to another issue. Vetteoz commented that the fuel pump has nothing to do with VATS. My experiences indicate that the fuel pump will run for a few seconds, even if the security light stays on. So the rails get primed regardless. However, if the pass key module is not enabled, then the ECM is not properly signaled, forcing the ECM from ever pulsing the injectors during crank. As long as that security light stays on, we know we have at least one issue to resolve.

 

[John Robinson]

Boom made the point that you should not hear the pump run during this condition and that this may be pointing us to another issue. Vetteoz commented that the fuel pump has nothing to do with VATS. My experiences indicate that the fuel pump will run for a few seconds, even if the security light stays on. So the rails get primed regardless. However, if the pass key module is not enabled, then the ECM is not properly signaled, forcing the ECM from ever pulsing the injectors during crank. As long as that security light stays on, we know we have at least one issue to resolve.

That is not the only thing that will cause the ECM not to pulse the injectors. The TPS will do the exact same thing. I know because I got sucked into buying a ECM only to find out the TPS was telling the ECM the engine was flooded and so the Engine would crank to clear the cylinders because the ECM was shutting down the injectors.

 

[starbuck]

So John, in the posting I put up about the fault codes, you're saying that a faulty TPS will prevent the starter from being engaged?
Which I guess would relate to the h53 fault code?

 

[John Robinson]

First an H code is a history code. That means it has happened and the ECM has stored the information as history. The FSM points out that it is related to running voltage from the generator. The heading for a DTC53 is System voltage. A system is made of many parts for instance the generator needs a good drive belt to create electricity. It needs good connections to the battery to provide the voltage to the battery. A bad ground will effect the voltage getting to the battery. So this is a not necessarily a problem with the generator or the battery but something else.

The H72 Code and the C72 code are the same thing again one is history and the other is happening. There are two things here to be aware of. First if you read the the flow chart you will see that in many cases as you diagnose for this problem you are being reffered to a bad circuit. That is the ground circuit they are reffering to. Second they point out that if the speed is less than 1 MPH (which it is ) then there could be a bad circuit in either the 232 or 108 circuit.

With what you have said about the storage being over a mulch bed and the fact that the interior has mildew in it if it were my car I would stop trying to find a part to replace and consentrate on cleaning up the ground points on the frame and bell housing. Even if the car had not been stored age alone would have corroded the circuit grounds. I would like to have all the money I have seen spent by others (and myself)replacing parts that were not bad. When I finally cleaned all the grounds on the frame and the bell housing most of my electrical problems went away.

I came from the shade tree mechanic school were all I needed to know was three things things to make an engine run. Did it have gas, spark, and air. If I fiddled enough to get the right combination of those things the engine would run. Well all that has been taken over by the ECM and the sensors it use's to decide how to adjust those three things. And for all of those sensors and the ECM to communicate they need good wires and connection.

 

[boomdriver]

Well,
sight of the forest has been lost due to all the trees in the way !

Whether the pump runs or not, or whether there is or isn't injector pulse is for now irrelevant.
Its the starter than is the current issue. Once the starter engages and cranks the engine then IF there is still a starting issue that can be addressed. In diagnosing anything, be it human disease or mechanical, one thing at a time.

The starter...as simple as a failed or sticking starter enable relay.

If that not be the problem then move on to starter electrical and key/ignition switch electrical. If the starter enable relay is functional and power IS flowing to both sides of that relay, then the question is "why is the starter motor not turning"?

Is there power to the solenoid? if so, that allows us to make a conclusion...the solenoid or starter motor is bad.

No power to the solenoid? trace the circuit backwards until you find the last or most recent place where there IS power. The fault is there. This exercise will lead you to the ignition switch/ key switch or wire between the steering column and starter.

The FSM will provide simple test to pin down the area of fault. Follow those and I can assure you that you will be able to find what the real problem is.

My best guess with the facts that have been presented and knowing some odds, and probabilities,...I'd go to the starter enable relay and jump that and chances are that will be the problem.

Regarding the fuel pump running during a security system alert, Oz is correct that the pump CAN run even with the security lite flashing. The pump has a 2nd circuit that allows power even if the primary circuit is laying in Utah. The pump does NOT always run, based on a number of things that the ECM decides (inj pulse, dist reference, TPS position) , but it CAN run during a security lock-out. The implied conclusion that it shouldn't is not accurate....VATS locks out the fuel injectors, and isolates the starter, not much else.
So, the system CAn still pressurize and the pump CAn run but the injectors cannot operate without permissions via VATS module thru the ECM that collects the necessary inputs and grants permission, If I am communicating this properly......

 

[89vetter]

Did we fix it yet?

 

[starbuck]

update---No-start. VATS Trouble? Check me on this

Just got divorced and moved the 95 to the new place and started working on it today with a friend.
Here's what we've done.

new battery

jumped the solenoid on the starter and it fired up and ran for 3 seconds then it shuts off
can hear fuel pump energize when ignition goes on.

pulled the starter enable relay and jumped two posts. car now starts right up with key and then shuts off after 3 seconds.

There is a non factory Excalibur alarm which is disabled but the wiring under the dash looks like a blind electrician with hand tremors was working on it

What is my next step.
We're reading as much online and in the FSM but still confusing and conflicting...so many damned acronyms.

thanks

 

[89vetter]

The purple wire from the starter needs to be traced back, this will include the safety neutral switch if automatic. Make sure battery is terminals are torqued to 11ft lbs.