PLEASE HELP - 93 MTX Will NOT Start!!!

[LookAtThatSHO]

Hello All,

Hopefully someone can provide some insight as to what might be wrong with my 93 MTX. I went to start the car earlier this morning, and without warning, it continuously cranked and cranked, but it would NOT turn over. Note that I did hear the fuel pump turning over. After about 10 minutes, the smell of gas was evident (flooded), and there's at least a half tank of gas remaining. So, I gave up, and went to work with my girlfriend's car. While at work, my father performed the Key On Engine Off test and got the following:

114 (O,R) IAT sensor out of range - IAT
116 (O,R) Engine Coolant (ECT) sensor out of range - ECT

Neither of these appear to be the culprit though.

After sitting for a bit, my father tried starting it again, this time with a test light attached. One end was attached to the end of the spark plug wire, while the other end made contact to the ignition coil pack. It did in fact start, but after he turned the car off, it has not started since.

After connecting a battery charger and letting it sit for a bit longer, we just went out to see if we were getting any spark with the test light. We are now getting NOTHING.

Thus, I am thinking that the problem has to be at the coil pack itself, or somewhere in line before the pack. Perhaps the PCM, or CPS (Cam or Crank)? Apparently, my father mentioned that there might be a condensor near the coil pack. Could that be what's causing this?

Any help/input would be greatly appreciated - I'm really in a bind here!

Thanks Again Everyone!
-Mike

 

[hawkeye18]

I hate to say it but it sounds a lot like a failing crank sensor. When it fails it will inhibit spark at the DIS. Check for voltage coming into the coil pack to make sure it's not the coil pack itself.

 

[LookAtThatSHO]

I hate to say it but it sounds a lot like a failing crank sensor. When it fails it will inhibit spark at the DIS. Check for voltage coming into the coil pack to make sure it's not the coil pack itself.

Thanks for responding.

We checked the voltage going in to the coil pack, and it read 12 volts. My father noticed that when trying to start it, if we push the ignition forward very quickly, it seems to start right up for the most part. However, if you turn it forward, and leave it forward (continuously), it hesitates, and then it doesn't want to turn over at all (electrical perhaps?)...

Next, we're going to check the voltage at the Crank Position Sensor wire connector near the top of the intake plenum. Also, I remember hearing the CPS begins to fail when a leaky waterpump drips on the sensor, causing it to short out. Well, we just replaced the waterpump and its seals about 10-15k ago. Is it possible that the CPS can just fail, period?

Any other suggestions?

Thanks Again,
Mike

 

[LookAtThatSHO]

Just an update: We ran the codes again, this time a 542 showed up:

542 (O,M) Fuel pump open, bad ground or always on - - Power / Fuel Pump Circuits

 

[Bob Gervais]

Ignore the 542, it'll show up sometimes when the car has stalled, or failed to start.

Check the basics... fuel pressure at the rail, spark (which you said you don't have). Does the tach move when you're cranking the engine? All four screws in the DIS module tight? All grounds good?

Pull your cam sensor and make sure it's not doused in oil, which is indicative of a leaky cam seal, and the need for a front 60k.

 

[93rev2sev]

Check the plugs on the DIS module. An out of nowhere no start is probably not the crank sensor.

 

[LookAtThatSHO]

Thanks very much for your responses.

I checked the DIS module, and it appears that its bolted tightly to the side of the intake manifold. Also, I pushed both of the connectors on each side of the DIS to make sure they were nice and snug. When we attempt to start it again, I will be sure to note weather the tach moves or not.

Now, we would like to test the voltage at the Crank Position Sensor, at the part where the wire connector meets at the top (passenger) part of the engine. However, I can not recall which wire connector is the CPS, on the top-left part of the engine (if you are looking at it from in front of the car). Can someone please verify which set of wires is the CPS? There are two sets that come through at the top of the intake manifold, one set contains about 4 or five wires, and the other just has one wire going in to the connector, and one wire coming out of the connector. Is the CPS just the one single wire going in to and out of the connector?

Thanks Again!

 

[LookAtThatSHO]

Ignore the 542, it'll show up sometimes when the car has stalled, or failed to start.

Check the basics... fuel pressure at the rail, spark (which you said you don't have). Does the tach move when you're cranking the engine? All four screws in the DIS module tight? All grounds good?

Pull your cam sensor and make sure it's not doused in oil, which is indicative of a leaky cam seal, and the need for a front 60k.

Thanks for replying Bob.

There is definitely fuel pressure at the rail. However, we are not getting any spark at the coil pack (confirmed using a test light). I'll be sure to check the tach next time we attempt to start it up. And all 4 screws appeared nice and tight on the DIS.

Which grounds would you recommend testing? And could someone please specify where the Cam Position Sensor is located exactly?


Thanks again for everyones' assistance!
Mike

 

[Bob Gervais]

Mike, not a problem at all.

I'm really just shooting off common problems with issues like this, some may or may not help so keep that in mind.

For grounds, there is a strap from the firewall to the intake, and also at the negative battery cable. This ground wire is a plug, and I've seen them come loose on some cars.

The cam position sensor is mounted on the passenger's side of the engine, on the rearmost cam. It's about 2 1/4" in diameter, made out of black plastic, with an electrical connector on the top of it. It's a little tough to see right off the bat, you may need to move the PCM wiring harness out of the way to see it completely.

It looks like a pain to take out, but it's not that bad. Unbolt the power steering reservoir, move it out of the way (using a bungee cord to hold it is really helpful), and you should be able to reach back there to get to the screws. If you have large arms or want more clearance, you can take the crossover tube (where the DIS is mounted) off as well. You'll need a 5.5mm socket for the cam position sensor bolts.

If you find oil in it, chances are that's your problem.

 

[LookAtThatSHO]

Just tried starting up the SHO again. We attached a voltage reader to the single-wire connector (hopefully, the CPS wire). We actually got a reading of about 3 tenths of a volt when attempting to turn it over. Also, the tach does appear to go down when cranking it over and over. Should this be the expected behavior?

Something else I should note, for the past couple of months, the Climate Control has been glitching, turning itself on and off periodically (front defrost mode), and it continuously blows out air at the highest speed. It's very intermentent in nature though, and I've been told it has to do with a failing speed sensor (located behind the glove box). However, I'm wondering if there is some sort of short occurring, which may be preventing the SHO from starting properly? Even now, when I had the key turned to the ON position, the EATC started glitching, and I noticed that the tach would move up just a bit as it glitched, then it came back down when it stopped. Also, since I bought this SHO, whenever I put the EATC on Max A/C, Vent/Floor, or Defrost modes, it always caused the engine to hesitate for a few seconds, and then it stops hesitating for a few seconds, and then it hesitates again, and then it stops, and so on and so on, until I turned the EATC off, or put it on a different mode. I guess what I'm trying to get at, is could this be causing the non-start issue currently?

One last thing, the ignition switch (where the key goes in) does not seem right to me. I am able to spin this ignition all the way around when the key is not in it. Also, when I put the key in and turn the ignition backwards to accessory, the radio or lights are no longer turning on. This has never happened before, until now. Maybe this might also be the culprite?

Definitely at a dead end here guys. Any input is greatly appreciated!

 

[93rev2sev]

since I bought this SHO, whenever I put the EATC on Max A/C, Vent/Floor, or Defrost modes, it always caused the engine to hesitate for a few seconds, and then it stops hesitating for a few seconds, and then it hesitates again, and then it stops, and so on and so on, until I turned the EATC off, or put it on a different mode. I guess what I'm trying to get at, is could this be causing the non-start issue currently?

The A/C compressor is probably engaging during the times when it hesitates. This would not cause a no start.

 

[LookAtThatSHO]

Just went out to try to start the SHO again. This time, we checked the voltage of the wires/connector that plugs in to the coil pack. With the key turned to the ON position, we got a reading of about 12 volts. However, when I attempted to START the car, the voltage dropped all the way down to ZERO. Additionally, all the interior lights, including the dash lights, turn OFF when the key is held forward in the START position (when the engine is cranking over).

Also, I went down and looked at my White 95 MTX to perform the same exact test, with the wires/connector that plug in to the coil pack. Sure enough, when we turned the key to START and the engine cranked, NONE of the lights turned off in the dash/interior, AND the voltage stayed right up near 12 Volts at the coil pack. A HA! Obviously, this is why there is no spark at the coil pack.

So, as a result, we are thinking that there must be a bad ground somewhere. Could someone please recommend where to start looking for this?


THANKS AGAIN ALL!
MIKE

 

[Bob Gervais]

Definitely not normal for the voltage to go to zero, or for the interior lights to go off when cranking. Check your battery cables, connections at the battery and starter, and have your battery load tested as well. Autozone, and most other chains, will test your battery free.

 

[LookAtThatSHO]

PCM / Ignition Switch / CCRM Failure?

Definitely not normal for the voltage to go to zero, or for the interior lights to go off when cranking. Check your battery cables, connections at the battery and starter, and have your battery load tested as well. Autozone, and most other chains, will test your battery free.

Thanks for responding Bob.

The SHO appears to be turning over just fine, with no real major hesitations that would otherwise be caused by a faulty battery or failing starter. It rather definitely appears to be a short somewhere, or bad ground perhaps. I'm currently attempting to obtain an electrical wiring diagram for ALL wires/connectors that are behind and leading in to the Coil Pack, particulalry to the PCM.

It's also definitely not normal that while the ignition is turned to Accessory, NO power is being provided to the INSIDE of the car. Hopefully, someone here on the forum has been in this predicament before and can help shine some light on the exact cause for this!

Thanks Again!
-Mike

 

[LookAtThatSHO]

Would anyone happen to have the associated Electrical Wiring Diagram referenced in the below Diagram, particularly where it says "SEE PAGE 149-6 FOR SWITCH TESTING" at the top (IGNITION SWITCH)?

We've taken the entire steering column off and inspected the ignition switch. There is a wire that's hot at all times in the RUN position. However, when the key turns to the START position (all the way forward), the Voltage drops from 12V to 0V; We're trying to determine if the Voltage drop is the result of a failing Ignition Switch or perhaps at the PCM...




Thanks in advance!
Mike

 

[AREA 91]

Just tried starting up the SHO again. We attached a voltage reader to the single-wire connector (hopefully, the CPS wire). We actually got a reading of about 3 tenths of a volt when attempting to turn it over. Also, the tach does appear to go down when cranking it over and over. Should this be the expected behavior?

Something else I should note, for the past couple of months, the Climate Control has been glitching, turning itself on and off periodically (front defrost mode), and it continuously blows out air at the highest speed. It's very intermentent in nature though, and I've been told it has to do with a failing speed sensor (located behind the glove box). However, I'm wondering if there is some sort of short occurring, which may be preventing the SHO from starting properly? Even now, when I had the key turned to the ON position, the EATC started glitching, and I noticed that the tach would move up just a bit as it glitched, then it came back down when it stopped. Also, since I bought this SHO, whenever I put the EATC on Max A/C, Vent/Floor, or Defrost modes, it always caused the engine to hesitate for a few seconds, and then it stops hesitating for a few seconds, and then it hesitates again, and then it stops, and so on and so on, until I turned the EATC off, or put it on a different mode. I guess what I'm trying to get at, is could this be causing the non-start issue currently?

One last thing, the ignition switch (where the key goes in) does not seem right to me. I am able to spin this ignition all the way around when the key is not in it. Also, when I put the key in and turn the ignition backwards to accessory, the radio or lights are no longer turning on. This has never happened before, until now. Maybe this might also be the culprite?

Definitely at a dead end here guys. Any input is greatly appreciated!

The A/C compressor is probably engaging during the times when it hesitates. This would not cause a no start.

Hello All,

Hopefully someone can provide some insight as to what might be wrong with my 93 MTX. I went to start the car earlier this morning, and without warning, it continuously cranked and cranked, but it would NOT turn over. Note that I did hear the fuel pump turning over. After about 10 minutes, the smell of gas was evident (flooded), and there's at least a half tank of gas remaining. So, I gave up, and went to work with my girlfriend's car. While at work, my father performed the Key On Engine Off test and got the following:

114 (O,R) IAT sensor out of range - IAT
116 (O,R) Engine Coolant (ECT) sensor out of range - ECT

Neither of these appear to be the culprit though.

After sitting for a bit, my father tried starting it again, this time with a test light attached. One end was attached to the end of the spark plug wire, while the other end made contact to the ignition coil pack. It did in fact start, but after he turned the car off, it has not started since.

After connecting a battery charger and letting it sit for a bit longer, we just went out to see if we were getting any spark with the test light. We are now getting NOTHING.

Thus, I am thinking that the problem has to be at the coil pack itself, or somewhere in line before the pack. Perhaps the PCM, or CPS (Cam or Crank)? Apparently, my father mentioned that there might be a condensor near the coil pack. Could that be what's causing this?

Any help/input would be greatly appreciated - I'm really in a bind here!

Thanks Again Everyone!
-Mike

The last time I had a customer's car in with a "no start" condition, it was a broken wire from the coil pack, to the dis module. This wire runs through the fuel injection wiring harmess.

 

[LookAtThatSHO]

Thanks for the quick response!

I asked my father tonight if he had tested the Voltage AT the DIS Module. Apparently, he said that the Voltage also dropped to 0 Volts at the DIS. If a broken wire between the DIS and the Coil Pack existed, wouldn't we get a 12 Volt reading at the DIS when attempting to crank over the engine (key in START position in ignition switch)? In any event, I'm really beginning to think this very well could be the result of a bad wire somewhere...

 

[medgraphsho]

I had this problem with my 92mtx and thought is was a broken motor mount causing the dis module to crack and dislodge.... it ended up being a bad connection to the starter... please just check the starter and make sure everything is grounded

 

[Bob Gervais]

I had this problem with my 92mtx and thought is was a broken motor mount causing the dis module to crack and dislodge.... it ended up being a bad connection to the starter... please just check the starter and make sure everything is grounded

Good advice Bill.

This may not sound like it's related to your problem, but bad connections at the starter will impede good amperage to the rest of the car.

The SHO takes a heck of a lot of amperage to the starter, corroded or poor connections can result in what your car is doing now.

 

[LookAtThatSHO]

Thanks a lot for the responses everyone. We'll check the starter. I know my father replaced the original battery with a brand new battery, and still no luck. I just received the Electrical Wiring Diagram (from firebat45 - THANK YOU!!!) to test the Ignition Switch. So, I will be sure to report back with the results!

Thanks Again,
Mike