Cadillac Deville crank but no start

[Otten33]

Ok I checked for spark again and this time I grounded tester.  I had spark on the ones I tested.  It didn't look very strong but it was sparking.  Also before sparking took place a loud crack occurred and I saw quite a bit of smoke and it smelled like burning electronics from middle of engine bay.  Could only assume that it was the starter.  After things cooled down i tried test again and that's when I started getting spark.  Makes me think I should go in and finally change that starter.  Ripped into it once before but bolts were seized.  I'll have to busted it out more than likely.  I still have new starter on hand.  Does what I described sound like the starter shorted out?  Everything else sounded fine afterwards as far as cranking goes.

[BodybyFisher]

What does from the middle of the engine bay mean?

If the starter turns the engine when you turn the key there is nothing wrong with the starter.

You need to explain where the spark and where the smell came from.

It sounds to me like you have a problem with an ignition control module bad connection corrosion you need to find where that spark and smoke and smell came from.

At the starter you only have two wires 12 volts from the battery and a lead from the starter switch to the cell annoyed there is very little that gets locked down there.

 

 

[Otten33]

I could not get situation to repeat itself.   It could have been from below the throttle plate.  Seems like that would be starter.  Starter has always smoked a little when cranking it over too much but not near as bad as today.  At least I always figure it was the starter.  What else could it be.  Other tries to crank resulted in no loud noise or further smoke.  Cranking seemed as before if that makes sense.

[Otten33]

Didn't see a spark.  I was testing for spark from coil plug.  I heard a pop or loud crack when buddy tried to start car.  I had no spark until afterwards.  Hope that helps bodybyfisher.

[BodybyFisher]

When you inspected the starter how did the 2 wire connectors look?  The starter itself is sealed and should not be responsible for any smoke or smells.

You know not to hold the ignition switch in the start position for more than 10 seconds correct?  If you hold it more than that, the starter 12v cable can overheat.  

Does the starter turn the engine over strong?

I think you are getting close.  

Did it seem that you were getting weak spark at some point?

 

[BodybyFisher]

You were getting a lean code for each bank.

Did you check for a damaged rubber plenum between the throttle body and the intake?  The damage usually occurs at the bottom if it is damaged bad enough, it could prevent starting.  

Lean codes can be caused by an unmetered vacuum leak or, too little fuel.  

Please check the plenum carefully for damage

[BodybyFisher]

This is the plenum

[rockfangd]

really common issue by the way. 

It may cause no start as there is too much air being pulled through it rather than the Throttle body

[Otten33]

I had no idea that a damaged plenum could cause a no start.  Misfire yes but didn't think a no start situation.  I'll go out and check it.  Also I am aware no to try and start car for more than 10 seconds.  I usually never do more than 3 or 4 seconds so that I don't drain down the battery.  Terminals on starter looked fine until I tried jumping them with a screw driver to see if the starter was working.  However smoke from cranking car had occurred beforehand which is why I thought it was the starter.  I can't see how the starter is sealed.  You can see part of the starter when looking down into engine bay plus the other end of the intake manifold is open but I will say smoke only seems to come from right side of engine bay when looking at it from the front of the car.  Drivers side I mean.  Looks like coming from below throttle plate.  

[Otten33]

Also I haven't put airbox and tube to the throttle plate back when running these tests.  Mass aid flow was plugged in though.  Would that make any difference on fuel pressure or spark test?  I wouldnt think so?  I also pulled fuel from the rails and it lite right up so gas is good.  Can you take plenum off without removing intake manifold?

[Otten33]

Typo on Mass air flow.

[rockfangd]

yes it would. Most cars today wont even run without that in the flow. 

I know fords wont for sure. Some are really picky

[Otten33]

I'll resemble it and see if it makes a difference

[Otten33]

Ok.  I resembled everything and created no difference.    Redid fuel pressure test and it maintained 38 PSI at key on and also at startup.  Bleeder value released almost no fuel.  Makes me think fuel pump is bad.  Also pulled codes again and I had several current codes.  There was DDM, PDM, IPM and IPC codes, but the ones that matter to us are the PCM codes.  I had 3 current PCM codes.  Pcm p0102 mass or volume air flow circuit low input.  Pcm p0016 crankshaft position - camshaft position correlation bank 1 sensor A.  Pcm p0341 camshaft sensor A circuit range / performance.   I replaced both camshaft and crankshaft sensor.  I think I may have a bad com.  How do I test the pcm?

[Logan]

41-47 psi is the spec from the GM service CD for the 2004 Cadillac Deville DTS. I would think at 38 psi the car would start...but maybe not. 

I have never heard of a rotted rubber plenum causing a no start....I guess it could be possible if you ignored it long enough. The rubber does not stop rotting just because the car is not being used. 

The intake has to come off to replace....they rot out on the bottom.....top of it will look new....but you likely need to look anyway at the starter. The rubber plenum is a dealer only item....about $20. 

Maybe the noise was a backfire? 

[Otten33]

Any info on PCM?  What's causing it from communicating with new AC Delco cam and crank sensors?

[Otten33]

Found this, could be my smoke problem.

 

Powertrain Control Module Electrical Ground Fault on Cadillac DeVille

Problem Description and Possible Solution

This powertrain control module (PCM) may develop a fault with its electrical ground location at the front of the engine block near the starter motor

[Otten33]

Said some was coming from where the starter sits but maybe it was a short occurring at the ground location of my PCM.  Could be why I'm having issues with PCM and would certainly cause a no start issue.  What do you guys think?  Should I rip back into top of engine and look at starter and if I can find this ground for the PCM once everything is put of the way.  Anyone know of a way to test a PCM?

[Logan]

I think the bulletin you mention is for the 4.9L and earlier engines. On the 4.xL engines there is a ground wire mounted to the front of the engine block next to the starter. 

Current issue thinking there was a major backfire.....causing some smoke in the intake.....smoke leaked out of the ruptured plenum boot.....which is located directly above the starter on a Northstar.

You really need a scan tool to condemn the PCM. There is plenty of stuff right now that needs to be verified before even thinking it's a bad PCM. Check for a ripped rubber plenum.....low fuel pressure issue....no spark issue... 

Then again....maybe it's a flood car...all the computers may be toast.

[rockfangd]

If you clear the codes do they all return?

If you have not already done so clear them

[Otten33]

I cleared the codes and the PCM codes didn't come back but I think they just didn't have time to set again.  I'll take intake back off and look for ripped rubber plenum.  When my buddy hooked up his scan tool to car he said he only got half the information he should have.  He's been a mechanic for 30 yrs but is not an expert on how Cadillacs work.  I would think this is a computer issue.  Still I will work to eliminate fuel and spark. Thanks for advice Logan.

[Otten33]

I have seen no signs of it being a flood car.

[Otten33]

I don't know if this is related but while looking for a remote starter under the steering wheel, I saw two orange or maybe red wires that had been spliced  terribly and while inspecting them they fell apart.  Not knowing what they were I re-spliced them together.  Seems a little weird that two wires would be spliced all together.  I mean 4 cut ends spliced together.  Could this be a ground wire?  They were fairly thick wires behind the knee panel below steering wheel.  Could this be related?

[BodybyFisher]

Please check plenum you would get pops and smoke, don't expand until you fix what you have wrong.  

Did you confirm fuel doesnt have water?, take a liter out and test.  My neighbor went crazy, absolutely crazy trying to start his Yukon, told me I didn't know what I was talking about, saying water was in the fuel, and.....WATER was in the fuel.  

[Otten33]

I didn't see any separation and fuel it's right up when I put flame too it.  I also drained a good portion of the quarter of tank that was in the car and add fresh fuel when I changed fuel filter.  I think my issue is volume of fuel as I can't seem to drain hardly any gas from the fuel rail itself.  I'll tear into intake manifold and thoroughly check plenum.  I did look at it when I had it out last but it could have been under the pipe bands as I didn't look very hard, just in the crevices.