Yacws ....

[critter]

.... or Yet Another Car Won't Start

I started it and warmed it up with the new engine, changed the oil, and moved it off the ramps and into another stall. It started once again, stumbled, and now won't start. I smell fuel and two fuses are good. The coils run off the same fuses, so that is not it. It is not the two step. It does pop once in a while, so there must be SOME ignition. The only DTC is U1000 - Class 2 data link ($60) Instument Cluster. Does this ring any bells for anyone? Seen this before? Have a clue?

Should I be able to log while cranking?

[joecar]

Is it an F-body...?

Off top of my head:
- other fuses;
- other DTC's (B1000/1 "option configuration error");
- VAT fuel disable (from BCM to PCM);
- Starter relay (from BCM to relay, inline with trans/clutch switch), prevents starter from cranking;

Are you getting cranking (sounds like it is)...?
Are you actually getting spark...?

Yes, should be able to log while cranking, if battery is sufficiently strong.

[critter]

Sorry Joe! Yes, F-Body. My Y2K race car we talked about a couple days ago.

All fuses in that block with INJ1&2 are good.

It cranks but won't start. It will pop once in a while.

I smell gas after trying to start it.

The only DTC is U1000.

Module search finds PCM ($10) and IPC ($60). Shouldn't it find a BCM (is that the right acronym?)?

I checked since posting, and I am getting spark.

What might it mean if FS won't log while cranking?

I don't have spare crank or cam sensors, so I may try to scope them.

[Blacky]

What might it mean if FS won't log while cranking?

FlashScan should scan with just "ignition on", doesn't even need to be cranking.
Or are you saying that it stops scanning when you start cranking? If so, could be a battery/voltage problem.

Regards
Paul

[joecar]

Oh, yes, your Y2K F-body racecar (I wanted to be sure)...

U1000 = "Class 2 Communication Malfunction" -> something is pulling the bus up or down, or is not letting go of it...

I looked at the circuit diagram, and the controllers that are on the Class 2 serial bus are:
- PCM,
- EBCM (ABS),
- SDM (airbag),
- IPC.

(notice that the BCM is not on it, see attached)

You're not seeing the ABS and airbag modules... with the EFILive scantool, goto Edit->Properties->Options and set Active Module Detection (if not already)... this detects modules by sending them a reset... so when you detect modules, they should all reset... the ones that don't get detected could be the ones being bad (U1000), or there could be a broken wire/splice.


Note the following, regarding the "absence" of the BCM from the serial bus:

the EFILive scantool does not detect a BCM (I just tried it on my 2K1 F-bird);

the Genisys scantool does not detect a BCM (I also tried it just now; sanity check: on other models it does detect a BCM, e.g. my Mrs' 2002 N-body Grand Am the BCM shows up on the serial bus, both scantools can see it);

The BCM feeds the PCM with a signal to enable fuel (...a square wave, or something...)... this seems to be the only comms with the PCM; but, you said you're getting fuel.

The BCM also enables the starter relay that is inline with the trans/clutch start switch; but, it seems that you're able to crank.

(I would still reset the BCM by pulling it's fuses for a few moments).

I assume all your grounds are good.

Are you getting actual spark...?

[critter]

FlashScan should scan with just "ignition on", doesn't even need to be cranking.
Or are you saying that it stops scanning when you start cranking? If so, could be a battery/voltage problem.

Thanks for the response.

I am not sure how to tell if it is logging. What I see is that I start logging, then try to start the car, but afterwards FS says nothing has been logged. I get the same result with V1 and BB logging - it gets active (leds flash) after I push the button but afterward transfer of logged file(s) fails because there "are not log files".

[critter]

You're not seeing the ABS and airbag modules...

It's a race car - it has neither.


the EFILive scantool does not detect a BCM (I just tried it on my 2K1 F-bird);

the Genisys scantool does not detect a BCM (I also tried it just now; sanity check: on other models it does detect a BCM, e.g. my Mrs' 2002 N-body Grand Am the BCM shows up on the serial bus, both scantools can see it);

First, that goes way beyond weird! But, my not seeing it does not indicate a problem. The VAT relink worked, but I dont' know if that would indicate the presence of the BCM.

The BCM also enables the starter relay that is inline with the trans/clutch start switch; but, it seems that you're able to crank.

Okay - that means the BCM is working - it does crank.


(I would still reset the BCM by pulling it's fuses for a few moments).

Certainly worth a shot.


I assume all your grounds are good.

I assume so, since nothing has changed since it ran. The car only has 15K miles or so, so the electrical connections are all clean and (probably) good.


Are you getting actual spark...?
Yep, I am getting spark. I can't tell whether it is at the proper time, of course. I don't know whether these things should crack a half inch spark, so I have no measure of the quality of the spark. Still, all 8 coils fail? Nah. Coils have the same supply as the injectors. I need to check the voltage with a DVM.

The more I think about it, it has to be something simple, like the crank or cam sensor, or the connection to it. An engine runs if it has fuel, air, and spark at the right time. It has fuel, air, and spark so the only thing left is the time of the spark.

[joecar]

You may be right...

Connect directly with PC/laptop, log while cranking [on dash page A (gauges) press Yellow button, or on dash page B (charts) press red button], see if RPM and cam sensor counts (there are several pids) show values...

[critter]

You may be right...

Connect directly with PC/laptop, log while cranking [on dash page A (gauges) press Yellow button, or on dash page B (charts) press red button], see if RPM and cam sensor counts (there are several pids) show values...
Well, it runs and I don't know why. It has taken a while, but I bought crank and cam sensors, pulled the intake, checked the cam sensor wiring, changed the sensor 'cuz I didn't want to pull the intake twice, dropped the starter, checked the crank sensor wiring, changed the sensor 'cuz I didn't want to drop the starter twice, checked voltages, ran a compression check, checked the valve timing in case the timing chain broke/skipped. I was beginning to think maybe the wheel on the Callies crank slipped. I don't remember if it was welded or not. I hooked up the laptop, selected crank and cam pids, tried to connect, and got an error. Something along the lines of the PCM saying "you can't do that!!!". Since I was allready wedged into the Kirkey, I selected another set of PIDs and turned the key. It fired and ran. It is too rich at idle and the measured AFR doesn't match the requested, although it is probably good. It is commanding 12.7 but getting around 13.5 Maybe I will change the sensors one at a time this winter, but the local track is only open a couple more weeks and I would really like to get out yet this year.

Thanks again for the help.

[critter]

Now I know why my car did not start .... the ignition will not fire the Autolite AR93 plugs gapped a 0.040". I have no idea why at this point. I thought I crossed them correctly from the NGKs, but maybe not.

[joecar]

Are you saying it won't fire those, but it will fire others...?

Does it run now...?

[critter]

Are you saying it won't fire those, but it will fire others...?

Does it run now...?

Yes sir, it runs on TR6 plugs but will not start witt the AR93s. If I use 4 of each, it will start and run, so I am beginning to think that the voltage may be too low during cranking. I used the biggest cable I could get when I moved the battery to the back, but there still may be too much voltage drop. I can't measure and turn the key at the same time.

[critter]

And it almost starts on Autolite AR473 plugs at 0.032. Maybe I should have left them at 0.025 like they came out of the box .....

Guess I pick up some TR6's on the way home tomorrow ....

[joecar]

What is "special" about the Autolite's...?

[critter]

They are "racing" plugs - semi side gap - the side electrode only covers half the center electrode. In theory, better spark. In practice, no spark :(

It seemed easier to buy plugs that way than to trim the side electrode like we used to do.