Still got a "pop" with DS...

S

streetknight

DCVING
Joined
May 26, 2001
Ok, it's getting frustrating now. I found my code 42 problem to be the Translator + and not DS.

BUT, With the ribbon cable hooked to the ecm the car would "pop" usually just once and nose over, then pick back up. On DS it would show that ALL the readings dropped to Zero. However, it didn't lose power cause the adjutments I had done to Timing and Fuel with the TT chip were still in place.

I have a shielding cable that is zip tied to the ECM and a Wire that is ran from the shielding cable to the firewall of the car to ground it.

I ran the car for 5 passes with no problems and out of the blue the pop was back. It did it 3 times in a row, so I decided to hook up the OTC and unhook the laptop. Made 2 more passes with NO pop without the DS hooked up.

Any ideas?
 
Look carefully where the card edge connector goes onto the ecm board. Sometimes the edges on the board are a little wide or narrow and the connector can shift sideways, intermittently shorting out some traces. Also, sometimes the connector can go on too far, also causing an intermittent short. If that's the problem Ken Chu recommends a toothpick in the bottom of the connector as a spacer to keep it from being able to go on so far - I've had to do that on about 3 cars so far.
 
streetknight said:
BUT, With the ribbon cable hooked to the ecm the car would "pop" usually just once and nose over, then pick back up. On DS it would show that ALL the readings dropped to Zero. However, it didn't lose power cause the adjutments I had done to Timing and Fuel with the TT chip were still in place.
Click to expand...

Mine does the exact same thing..... but it still does it even with the DS ribbon cable unhooked........ very frustrating......I have narrowed it down (I hope)... to a intermittant power loss at the ECM.......I plan on temporarily hot wiring the ECM and drive it to see if it does it again.....

oh.... mine seems to only do it when it is full operating temp...... doesn't seem to do it if you try to make it do it within the first few minutes of driving.....but after it gets to full operating temp..... it will "nose over" and pick right back up without fail.....

Interested to see what kind of responses you get....
 
Does your car do this at normal driving or just WOT. Mine is just WOT.

I had some issues I thought were DS before that were T+ related, use the jumper wire and that problem is gone.

Also, When yours acts up, are you values on the BLM table ALL back to 128?

It should be if the ECM is actually losing power. All my sensors go to zero, but when it picks back up all the values are still as I adjusted them.
 
Electrical Gremlins!

streetknight said:
Does your car do this at normal driving or just WOT. Mine is just WOT.

I had some issues I thought were DS before that were T+ related, use the jumper wire and that problem is gone.

Also, When yours acts up, are you values on the BLM table ALL back to 128?

It should be if the ECM is actually losing power. All my sensors go to zero, but when it picks back up all the values are still as I adjusted them.
Click to expand...

I guess you might not pick up the stumble unless you are in the gas enough to go into some decent boost (like 6 or more lbs)

I looked at my DS logs.... my BLM's and INT's go to 0 and my spark advance goes to 0 as well. My BLM table still shows 128 in all the cells though......???? So does that mean my ECM is not loosing power?

I had hope that a temporary hot wire would keep mine from stumbling.....but am not sure now.......

At least if mine was loosing power for some reason.... I can fix that....

oh.... my coolant temp goes to like -37 when this happens as well.... does yours? Almost all other values just go to 0.
 
I'm no expert, but try this. Let the car idle for a little while and the low cell BLM's should not be exactly 128. You know how they go up and down? When you turn the engine off and turn the switch back to the 'ON' position your BLM table should still be at the same value "usually not 128 on my car".

Take a note of the values. Then go drive the car till you get the "pop" If ALL your values are back at 128 right after the pop, then IMO the ECM is losing power. Just like you just unplugged the wire under the hood.

Mine doesn't do that. It did before, but I'm pretty sure I got that fixed and was the T+ causing the problem. Now, all the sensors just drop out at WOT in random places, sometimes 2nd gear sometimes 3rd. BUT my BLM tables are just where they were. Like when I change timing or fueling via the TT chip.

Keep me posted cause mine ain't fixed yet :)
 
ds file sent

Streetnight,

Sent you an email of my DS file...... that shows the cut out. Look pre-trigger about 9.99 seconds......

Thanks.
 
I'll try my best to look at them when I get home. If I can figure out how to download them to a floppy. I'm still old school :)
 
Streetknight,
At one time, I had all the problems you are describing, pop with all BLM's being reset during WOT in any gear and at any RPM, ecm seemingly loosing all power for a split second, est codes being set. The cure for me was a shielded and grounded ribbon cable cover and a small spacer in the ribbon cable connection to the ecm edge connector so the connector didn't push on too far along with a spotlessly clean edge conector when viewed under a glass.

Hope you figure it out.
 
Blazer406 said:
Streetnight,

Sent you an email of my DS file...... that shows the cut out. Look pre-trigger about 9.99 seconds......

Thanks.
Click to expand...


Streetnight,

I looked at your DS file. It appears at first glance to be doing exactly what mine is doing. My only difference.... is that my car seems to do it (pop/fart)w/o the DS cable even attached..... no difference with or without the cable attached. I might try grounding my ECM directly.... and see if it might make a difference on mine. I have a few extra braided ground straps I got from work...... :D
 
Blazer, you might check your grounds at the back of the PS head as thats where all the ecm grounds go.
HTH
 
Let me know what you find out. Mine might be the same thing. It just comes and goes I guess. I'm thinking of relocating all my grounds to a junction box.

I know a previous owner had the engine out of my car, maybe they didn't get all the grounds right :(
 
Just for what its worth, I took both sets of grounds off the head and bolted them to an ilet on a piece of 10ga wire and ran it to the bolt where the battery ground wire goes to the PS fender. Cheap and worked for me, I wasn't going to take any chances with all those wires possibly having a bad ground.
 
ttt

Well,

I have tried the extra ground from the ECU to the seat bolt.... and tried a temporary direct hot wire (fused) from battery to the ECU/Ignition fuse on the fuse panel......

Neither one has solved my problem.....

Next is to try some extra grounds from heads to firewall.... it is hard to see behind the heads... so I might just run some extras... to test to see if that is it.....

Streetnight.... you had any luck?
 
Nah, I found that all my grounds were in place. Got a really short DS cable, about 6" I think, but never had a chance to install, got a head gasket first.
 
Update! (Long)

Well,

I have made progress. I was on the way home from the track Friday night.... and it stubled once leaving away from a stop sign.....the radio blipped off momentarily when it stumbled.... I never noticed that earlier... b/c I didn't have a radio in the car.... or didn't have it on when it stumbled....Well..... that got the brain to turning....I WAS loosing 12v to the inside the car.... and that loss of 12v was causing the ECM to stumble.....

Fast forward to tonight.

I figured out it was time to tighten all battery cables and grounds coming off the alternator and battery. I had just tightened up the battery cable going to the starter and the battery cable going to the alternator. I took it out for a test drive.... got her up to operating temp.... went through the gears under a little boost :biggrin: ..... it seemed to be worse than before (the stumble)..... I went on to the gas station close to the house and filled up (I was going to do that anyway). I drove it home.... right before the house... there is a long straightaway :D . I stalled it up to about 2 psi... and launched.... it stumbled near the top of 3rd.... I stayed in it.... it stumbled like 6 or 8 times.... never did that much before.... usually only once or twice.... so I let out.... it was still stumbling....never EVER done that before.....(after I let out)...... was beginning to wonder if I was going to make it back to the house.... Got home and pulled it up in the garage.... stalled it up to about 1 psi...... it stumbled..... I let it idle... and popped the hood..... looked everything over.... and it stumbled while I was looking at it....then I saw it.... a small spark shot out from under the pass side header.... I must say.... I am relieved. I finally figured out what I feel (99.9% certain) that this was the problem. The battery cable was shorting out to the under side of the pass header. I made it worse when I tightened the battery cable... and it swiveled slightly closer to the header. I knew when I test drove it it was worse.... now everything makes more sense. Early in the troubleshooting process I made a temporary hot wire straight from the battery to the ECM.... it didn't help.... that had me stumped......Now that I found it..... what was happening was that when the battery cable would short out to the header.... it was dead shorting the battery to ground (only momentarily). This would cause the voltage of the battery to go to 0 ... (along with the voltage in my temporary hot wire). This is why the ECM still stumbled. I don't know if this is streetnights problem..... but I am almost certain... it is my problem. I hope this helps.
 
fingers crossed....hope thats it for ya...good find....an intermittent like that can drive people nuts for a long time..keep us posted.
 
Thanks for the info. Unfortunately I popped my engine a while back before I could find the problem. I just put it in yesterday, So I'll make sure all that wiring is tight and routed correctly.

Thanks again and I'll keep you posted.
 
Streetknight... now that you have your car back on the road.... do you have any "pop" .... ???
 
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