here with circletrack, no spark

[93rev2sev]

in the garage now forgive the poor grammer...

it's an ATX with a fresh motor. we get tach signal even if we disconnect cam crank and coil. it lifts off the peg and then while cranking settles at about 400rpm.

fuel pump is off (race car)...

looking for rapid fire suggestions.

 

[St Louis SHO]

DIS? Is the CEL dim?

 

[93rev2sev]

nope CEL is a bright momentary flash as key is turned

 

[93rev2sev]

codes were 542....pcm always bad with this code?

edit PCM was not grounded ...fixt... still no spark

 

[Bizzy]

What was done to the car recently? Have you checked vRef? That is what my whole problem was back a couple of years ago when we did the clutch. We got the connector for the EGR (that wasn't used in my car) stuck between the bell housing and the block and it shorted out vRef.

 

[93rev2sev]

CircleTrackSHO here.. what is vRef ?

Also.. where would I find the "IDM(Ignition Diagnostic Moniter)" ?

 

[St Louis SHO]

reference voltage: IE all your sensors have a 5v ref signal. check to see if you have 5v at the tps and go from there

 

[Bizzy]

Have you checked the coil pack with a known good one?

Tom, I left you a voice mail.

Edit: The Ignition Diagnostic Monitor (IDM) is an output from the IRCM that provides diagnostic information concerning the ignition system to the PCM for self-test and is also the input signal for the vehicle tachometer.

 

[hawkeye18]

Make darn sure the DIS is grounded well. I had an IDM code thrown when I forgot to tighten the two crossover tube - intake bolts.

Also, bottom two bolts, heat sink paste, etc. etc.

 

[93rev2sev]

upon discussion, it was noted that the person that worked on the car before me had a bright idea...

hotwire the crank sensor with 12v..attached to a toggle switch.

So it's cooked...right?

 

[egroce11]

Same thing has happened on my race car/ Car ran pulled the intake for powder coating and now nothinmg wantws to fire. People working on it for me can't fin d athe problem.
Pardon the typping I'm still on a lot of pain medsw

 

[93rev2sev]

It seems to me that if there was a problem with vRef, we would not have been able to pull codes.

I've suggested to CircletrackSHO that we do a front 60k including a crank sensor(a good measure on any engine with unknown history, regardless of spark). I guess I'll swap the coil pack with a known good unit before tearing the front end down, but I'm not confident his crank sensor survived the 12v toggle switch idea.

I've also suggested a set of rod bearings.

 

[93rev2sev]

Ernie, make sure the powdercoating isn't interfering with engine ground.

 

[CircleTrackSHO]

When we started.. we had no Check Engine Light at start up.

We discovered a broken ground wire between the computer and the battery.

Then we got a 511 and a 542.

That would make sense.. as 511 is ungrounded ECU, 542 is fuel pump issue, which I have on a switch and we had it off.

So we think that was the original problem.

We cycled the battery and CEL threw a 111

So we were back to no spark.

We ran THIS TEST PROCEDURE and found the anticipated voltage on cranking.. however, we did have 12v before cranking.. is that normal ?

However... the person I had helping me before I called TP thought the no power to crank sensor could be fixed by running a hot wire directly to the Crank Position Sensor.

HONESTLY -- this wasn't me !

Anyhow.. he stripped back about a 1/8th of the power lead to the Crank Position Sensor and ran a hot wire off the battery directly to it.

Of course, that didn't work.. because he still had a broken ground.

We think he fried the Crank Position Sensor doing this.. so while we fixed the bad ground, we now have a fried Crank Position Sensor.

So.. we are going to try a simple double check - Replace CRRM and ECU with fresh known working units and try to fire. IF we still have no spark, then the plan will be a front 60K and fresh Rod Bearings while we are in there.

Should be completed sometime on Thursday evening, we will update on Friday.

 

[93rev2sev]

Circletrack,

The computer you want is a d4u1

Check the donor car by opening the passenger door and looking for a white sticker on the a-pillar.

 

[hawkeye18]

Did you check the ground strap to the rear intake tank? Did you ohm out the bottom two DIS bolts to the neg. post? If it's more than .5 ohms, you have a ground issue.

Your crank sensor should be ok... it's just a magnetic sensor... but the PCM input might have gotten fried, or the DIS might've.

 

[93rev2sev]

No(grounded DIS with bottom bolts DIRECTLY to the body..and then the body to the battery using the same bolt hole...the ground is good...guar-an-flipping-teed).

I've never seen electronics that liked to be backfed uninhibited voltage.

That said...I think were going to get another computer for good measure.

We've tried a known good DIS module...

IRCM is good (now that it's grounded) according to this...
http://jr.rustecat.com/articles/ircm/
Also according to above, the IRCMs IMPORTANT job is to power the EEC and the fuel pump. The EEC is powering up fine and the fuel pump is on it's own 12v switched circuit...and we hear it whirring when we toggle the power.
I've never heard of a testing procedure for the crank sensor but would really like to see one...

Remember, we ARE able to pull codes by employing the good ole' paperclip trick...does this mean the PCM is good? I'm guessing yes.

Coilpack...is next. I'll be swapping his for mine tonight.

 

[Bizzy]

I would imagine that if you can pull the codes that it should mean that the PCM is ok, but I suppose nothing is written in stone. You might consider having one on stand by just in case. Only thing about that is that if there is still a problem, you don't want to fry another one if the one in there now is in fact fried. (does that make any sense at all? ) I'm putting my money on the coil pack....a whole $5.00.

Back when I had the vRef issue, the short to ground apparently caused some damage to the PCM, but the funny part was that it let the car run correctly but we were unable to download any codes from it.

 

[hawkeye18]

Eh... circuitry does not like rogue voltage, but the CKP is seriously just a switch... a magnetically activated switch. You could feed it 110VAC and it'd be fine. Whatever is upstream of the switch is what's gonna go all R2-D2 on you (you shot my hair!).

If you're pulling codes from the ECU, and it's giving you a 111 (or 511 if you have a chip installed - 511 means ROM checksum failed), then the ECU is more than likely ok. If you have a circuit light, you can hook it to the coil pack input (harness side plug), and if it starts blinking rapidly then you're getting a signal into the coil pack... at which point I'd be rippin' that sucka outta there.

 

[93rev2sev]

any idea which wire is the input to coil?