Grand Prix no start mystery

[Sunspot]

Looks like original injectors, I now have the car inside and I am going to see if temperature makes a difference or if it was just coinsidnece that something else happened while it sat outside.
I hope this story has a good ending!

[3100]

Drive it around with scan tool connected and when it stalls again post your freeze frames here good luck.
Also connect fuel pressure gauge and tape it to the windshield while you are driving so you can monitor fuel pressure when it is about to stall.
When it fails to start connect scan tool and monitor ckp signal when cranking.

[Sunspot]

This car currently will not start and run, so I can't drive it around. The stal problem was before I parked it over the weekend. Now it seems to be a bigger problem. I can post readings for key on engine off, but not running.
I have great blue spark at coil packs
50psi fuel pressure

[Sunspot]

Key On Engine Off Readings:
Ignition 1 12.3 v
IAC Position 102 cnt
Air Fuel Ratio 8.0 : 1
Current Gear 3 ????????
Fuel Trim 2 cnt
Fuel Trim Learn Disabled
Injector Pulse Width 49.9 msec
Long Term FT 0
MAF Frequency 0 Hz
MAP 29 inHg
Short Term FT 0
18x Crank Sensor 113 rpm ???????
cam signal present

Now I am not sure why it says current gear is 3 when I am in Park.
That reading doesn't change when I move the shifter

Also, why does the Crank Sensor read 113 rpm with key on engine off? Shouldn't that read with RPMs ? so if the engine is not turning, why does it read 113? maybe this reading is correct though.
Anyone shed some light for me, please

[Rodgerwilco]

Going back to the original problem, I would suggest checking the work he did on the intake gaskets. I say this because I had the same type of problem on an old 75 Toyota that I had apart. I didn't have the intakes tight enough and there was a vacuum leak around the gaskets, causing the engine to stall out unless I "feathered" it. The temperature change you say you had between inside the shop and being outside could make the difference since the block would expand some in the warm air of the shop and "close the gap" as it were between the intakes and the block, thus decreasing the vacuum leak to the point where it would start.

IMO it sounds like you have an intake vacuum leak, since the previous guy had them apart.

All the other stuff you are doing may just be leading you down the "rosy path" so to speak. :-)

[Mickey#1]

What kind of scanner are you using?

[Sunspot]

using Genysis Scanner

[Sunspot]

as stated previously
No Current Codes

Still wondering if anyone can shed light on those readings I posted

[3100]

ckp should not show that with engine off, you can test ckp by disconnecting it at the icm and connecting dvom to ckp's connector (dvom should be set to read mV AC) so while someone is cranking you shoud see about 200mV AC

[Mickey#1]

Can't imagine why you're getting those readings.

Here's a couple other things you can check.
Make sure there's no fuel in the vacuum line going to the fuel pressure regulator.
Check voltage at the battery while cranking. Make sure it's not dropping below 10 volts.
I'd still like to know if the plugs are wet or dry after not starting.

[tblake]

Are you able to have an assistant crank the motor while you spray carb cleaner at all the gasket mating surfaces to see if it will try to start? Maybe there is a large vacuum leak.

Your readings may be a moot issue since the motor is not running. But never know. Does the cps sensor reading change as you crank the motor over? If so its probably ok. One thing I am wondering about is the 8 to 1 AF ratio. Not sure if that is again because the motor is not running, but it should be at 14.7 to 1. What is the scan tool say the ECT is? Compare it to the IAT temp. After sitting overnight, both should be the same.

I am trying to thing of a sensor ground that would need to be disconnected to do LIM gaskets. I know there is one over by the coil bracket, but that one shouldn't be touched for LIM gasktes.

The PCM wasn't swapped over to an aftermarket tuned one was it? I'm sure you probably dont know since you are fixing some one elses mistakes.

Is the MAP sensor plugged in, and is the vacuum line to the MAP good? A friend of mine has a 98 regal gs with the L67 and he just got done replaceing his LIM gaskets and had a similar issue. The car ran good for a few days, then it stalled out and would not restart. His issue turned out to be a cracked vacuum line to the MAP sensor.

Your shop must be making BANK on diagnostic time for this one!

[Sunspot]

Tried the old carb spray trick, nothing changed
As for the Crank sensor, the readings do change while I am cranking, but mostly comes back to rest somewhere near the reading that I posted, while cranking though it went all the way up to 11,500 at one point, yes I mean 11,500. maybe that is normal though, seems awfully high.
Map reads right where it should
As for diagnostic time, it is one of those that you can't possibly charge what you got in it unless you have the conscience of a Doctor or Lawyer!

[Sunspot]

also no fuel in the Pressure regulator vacum line

[HotZ28]

You have fuel pressure, but are the injectors firing? What is the TPS (closed throttle) reading with KOEO and will it vary with opening the throttle position the way it should? Have you tried another ICM? This problem sounds like a PCM, but verify the above first.

[troy1]

Are your grounds on the bell housing bolt tight? how about the battery terminals corrosion free and tight?