95 ATX not starting

[Biggie]

I have a 95 SHO ATX which is no longer starting. The engine and tranny has been swapped and rebuilt with full 60k. For the first two weeks the car was running with no problems. I have also installed a new coil pack and wires.

A couple of days ago, the car was not turning over in park, but would in neutral, but wouldn't start. I checked to see if there was spark and there was. When I poured a bit of gas down the intake the car started. I let it run and then a few minutes later I tried starting it without the gas, but it wouldn't start.

Today, I tried starting the car again, but wouldn't start, even with the gas. I checked to see if there was spark and there was no spark. I wasn't able to find any fuse or wiring problems.

Also, I changed the neutral safety switch. The car was then turning over in park for the first couple times. Then afterwards, it would not longer turn over in park.

I'm confused...anyone able to help?

 

[rubydist]

first, check for codes and let us know what you find.

the 'no crank' condition in park sounds like the mlps switch is not adjusted properly. that is the big thing with the wire coming out of it that sits on top of the transmission just under the arm where the shift cable attaches. that switch tells the pcm which gear the trans is in, and the pcm must 'see' park or neutral to allow cranking.

that seems separate from the 'no start' condition where even when it cranks it won't start. you mentioned that the 60k work has been done, but not how long ago that was. I have seen new crank sensors go bad very quickly, and I have seen crank sensors get destroyed very quickly due to not being gapped properly, so that is a suspect, but you need to look at the codes because that should appear as a code if its bad. there are several other suspects as well (dis, pcm, grounding, coils, etc.) so it pays to check codes.

 

[Biggie]

I was able to get the car running today, but only starting when I pour a bit of gas down intake. I am thinking it could be that there isn't enough fuel pressure. When the car is running and I shut it off and try starting a couple seconds later, it will start. But if I let it sit for more than maybe 30 seconds, it won't start. I think it could be the fuel pump or pressure regulator. Anything else perhaps it could be?

I checked codes and got a couple but they weren't relevant.

The past couple days I changed dis,pcm,coil pack, and cleaned all ground connections. Took out a stupid remote car start and security system and still wasn't starting.

I adjusted the neutral safety switch and the not turning over in park problem is now fixed.

Thanks for your reply rubydist!

 

[rubydist]

ok, so tomorrow before you try to start it, check for fuel pressure at the fuel rail. Even if you don't have a gauge, just (carefully) press a pen on the center stem of the schrader valve. If there is no spurt of fuel, you have no fuel pressure. If there is no fuel pressure, turn the key to 'run' for 3 seconds, back to 'off', then repeat that process 4 times. Then check again, you should have fuel pressure now.

If that is what is going on, then you have either a leaking check valve in the fuel pump (replace fuel pump) or a leaking pressure regulator (replace regulator).

 

[projectSHO89]

A leaking fuel pressure regulator can be quickly checked by just pulling the vacuum line. If the diaphragm has been leaking it will be obvious.

I hate to hear about leaking diaphragms....

 

[Biggie]

I checked the pressure at the fuel rail with the pin and there wasn't much. When I turned the key to run 4 times there was pressure. When I checked the vacuum line doing that same test, there was no fuel coming out of the regulator.

 

[rubydist]

so after you do the 'key on/key off' thing 4-5 times the car should start fine. if so, you can drive it like that as long as you can put up with the little hassle. eventually, you will need to replace the fuel pump.

 

[Biggie]

I tried the turning to run 4 times and then start but it didn't start. So I tried another 5 times and still no go. I then changed the pressure regulator first before going to the fuel pump. Still no go.

I took the fuel pump out and noticed that it has a pulse dampener on it. Could it be causing a problem...and do I need it?

 

[Biggie]

Changed the fuel pump...still having same problem.

Before I started car, I did the run on and off over 10 times and the car started fine. I let the car run for over 10-15 minutes, try again and won't start.

 

[SHOdded]

If you can get it to run again, I'd take the opportunity to grab the codes. Because of the swap, I still suspect electrical issues like rubydist originally stated (grounds, PCM, DIS, etc.). BUT you could have had a tank of bad gas, or be having a case of gas tank rot if the car sat long enough. Also, when was the fuel filter last changed?

 

[Biggie]

Thank you to those for the help so far.

I have changed the fuel filter and pressure regulator already. When I turn the key to run once and do and check the schrader valve with a pen there is pressure. I do not have a gauge to tell you exactly how much but it seems fine.

I tried to get the car to start today to park it for the winter now. But it didn't start, even with gas down intake.

I did a KOEO (key on engine off) code test today and got some results this time.

121- Closed throttle voltage higher or lower than expected
327- EGR valve position circuit below minimum voltage 2. EVP/EPT circuit below minimum voltage.
216- DIS fault ignition system coil.

I am thinking it could be one of the sensors.

 

[rubydist]

121 could be a significant part of your lack of starting, as the pcm uses the tps as one of the major inputs to determine how much fuel to provide. if the pcm thinks there is no air going in due to the tps being too low, it may not provide any fuel to the cylinders.

216 is more likely your problem - either the dis or the coils or the wiring is not playing nice and there may not be any spark.

you need to next check to see if there is spark or fuel or both in the cylinders. I would check for spark since you say that even with pouring in gas you didn't get it started. I suspect you have no spark at this point.

 

[SHOdded]

Would clogged EGR nostrils be a possibility also with these codes, rubydist?

 

[Biggie]

Today I checked for spark and there is spark as well as fuel. Still no start.

I already replaced the pcm with a good working one.

Today I also replaced the coil pack, ccrm module.

Any other ideas?

 

[rubydist]

ok, so you checked for spark by pulling a wire off a plug and there was good spark?

and how did you check for fuel?

did you replace the tps yet?

 

[Biggie]

I didn't replace the tps until today rubydist...and that was the problem!!!

Starts great now! So, a note to others...another symptom of a faulty tps is that the car won't start.

Thanks for all your help guys. :thankyou:

 

[SHOdded]

Awesome! Score another one for rubydist I recently replaced the TPS on my Intrepid and now it starts like a champ (used to crank forever). No codes there either!

 

[rubydist]

lol ! as they say, even a blind squirrel finds a nut once in a while.

so for some guy reading this in the future wondering why I asked the questions I did, here is a little more detail:

I am guessing he checked for fuel by checking pressure at the fuel rail. Having pressure there is critical, but does not ensure that there is fuel getting into the cylinders. If the tps tells the pcm that no air is going into the engine, the pcm will not command hardly any fuel, so it won't start. Fixing the tps allows the fuel in the rail to be sent into the cylinders.