Administrator
Failed ign. sw. is certainly a possibility.Originally Posted by Robyn
It's not a fuel or PMD problem. It starts, then stalls, with the accompanying security fail code, exactly as the DTC describes. Once started normally, if the signal isn't sent, it immediately stops the fuel injection. Ign. switch, BCM, or PCM. In that order, or a connector or wire in between.
Enthusiast
Checked out the the fuel shut off solenoid,it works and the power to it is uninterrupted through cranking.
Found the BCM and it was connected good and doesn't look like it's been ever removed.
For grins i called the local GM dealer about an ignition switch $487.00 plus tax 4 weeks away.
Will call Banks in the morning and see if they have any records of their kits from the 6.5 days.
Hoping to talk a local guy into having a look,his shop burnt down a few years ago,at the time he did all the computer stuff around town.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews
Enthusiast
That is why I mentioned the oil pressure switch. During the start cycle, the oil pressure switch circuit is bypassed until it sees oil pressure. If the switch is bad it would produce exactly the symptoms described.
Just a thought and if I'm correct would be a relatively cheap fix.
Bill
91 Buick Roadmaster/Avant 6.2 NA conversion (gone but not forgotten)
94 Cadillac Fleetwood (sold)
08 Aerolight 23TT
06 Vortec Max Silverado CC SB (sold)
10 Avalanche (electronic quagmire but love the truck)
Enthusiast
Hi Bill
I will give that a try i have a spare one.And cross my fingers.
Called Banks,that was a waste of time.
I might have time to try the oil pressure switch today.
Thanks all.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews
Administrator
This only applies to OBD-I. The OPS is redundant on OBD-II trucks. The lift pump is controlled/relayed by the PCM. OP says the lift pump is pumping at the start cycle, and has good fuel pressure. Even if it quits after a start, the engine shouldn't stall.
Proud Deplorable
I agree, however, that's exactly what my '93 did when the oil switch failed. Maybe it also needed a new fuel filter...
The Constitution needs to be re-read, not re-written!
If you can't handle Dr. Seuss, how will you handle real life?
Current oil burners: MB GLK250 BlueTEC, John Deere X758
New ride: MB GLS450 - most stately
Gone but not forgotten: '87 F350 7.3, '93 C2500 6.5, '95 K2500 6.5, '06 K2500HD 6.6, '90 MB 350SDL, Kubota 7510
Missy Good Wench ( Moderator)
Just a thought.
Do some creative wiring to the Fuel shut off solenoid so you can get a volt meter reading.
Turn on the key...."Observe the reading" Crank the engine....."Observe the reading"
Engine starts....."Observe the reading" DOES THE SHUT OFF SOLENOID SUDDENLY LOSE POWER WHEN THE ENGINE DIES ?????
If power is lost just after the engine starts then this would point the finger at the security system shutting things off.......
If the vehicle does not have a chip key ????? is it possible that the key fob activated door lock system (If equipped) was used to lock the rig and never turned off ??????
The BCM handles all the security features.....If it has either an issue (Fault) or something has been fooled with ????? Radio/sound system swapped.....or other issues that can trip the ANTI THEFT SYSTEM ???????
Administrator
Yours was a mechanical OBD-I. This is an OBD-II. The OPS serves a different function.
If the lift pump stops pushing fuel, for any reason, the engine shouldn't stall. That doesn't mean it won't, for other reasons. Your 93 had other issues, such as a fuel filter, air, or weak IP, or it wouldn't have stalled. The problem with this 98 is electronic.
Something changed since it was driven into the garage. If not for the P1626, it could be any of the above suggestions. Until that DTC is resolved, it doesn't matter what herring is pursued. Diagnostics must start with what is known.
Proud Deplorable
I agree, I'm just saying, sometimes it does stall, for whatever reason.
It's easy enough to tell if the lift pump stops before or after the stall.
The Constitution needs to be re-read, not re-written!
If you can't handle Dr. Seuss, how will you handle real life?
Current oil burners: MB GLK250 BlueTEC, John Deere X758
New ride: MB GLS450 - most stately
Gone but not forgotten: '87 F350 7.3, '93 C2500 6.5, '95 K2500 6.5, '06 K2500HD 6.6, '90 MB 350SDL, Kubota 7510
Administrator
It could have a potato in the tailpipe. Nothing works until the P1626 is resolved. The diagnostic cycle is ran at every start, and it resolves or fails within 1 second of a start. The truck ran before being driven into the garage, then later didn't, tossing the P1626. Very few conditions cause that, and when it happens, the PCM only stops sending power to the fuel injection solenoid (not the ESS). Something changed, either someone messed with something, or something failed. It's only that simple. If that is resolved, and it still stalls, or whatever, then chase the other possibilities.
Enthusiast
Hi All
I really appreciate the help,without it i would be lost.
I did check the OPS,it's fine.
I did check the shut off and it's fine,didn't do a voltage check,just checked power with a test light.
The computer told me there was an issue with the solenoid after i messed with it and checked the codes.cleared them and the two earlier ones came back.
I pulled the plastic cover off the steering column and saw a couple electrical things near the ignition switch that i don't remember seeing before,my assumption is they are part of the chipped key.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews
Enthusiast
A history of the truck again without it cluttering up other posts
Truck was abandoned after the PO could not get it to run,sat in my yard for 5 years till PO family bailed on it.
I cleaned out the truck and worked to get it to run,i had to rewire the lift pump and the converter was plugged solid.Removed it and it fired right up and filled my shop with soot and black smoke.Truck started fine didn't run great lot's of smoke.There were no brakes at all so i never took it on a road test to see if it would clear up.At the time my thought was the injectors suffered from the plugged exhaust,maybe had soot forced back in them because of the back pressure.
Fast forward a couple years
I installed a couple batteries and it fired right up,smoked bad still.Very low on power and was surging when the accelerator was pushed down.I had to get it rocking to move out of the depressions the tires made from sitting for a couple years.I drove around the yard lots of smoke no brakes so it was slow and controlled.
Drove it into the shop shut it off. Since then it has not run after the initial start sequence.And each short burst of running makes black diesel smelling smoke.
I only have a key with black plastic,i did find a key fob when i cleaned out the truck which doesn't work.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews
Administrator
The code, and behavior, is specific to the Key-On start cycle. Not the fob. A security fail of the fob, intentional of otherwise, clears at one key cycle. I don't believe this is a "chipped" key model. Rather, the lock cylinder, when turned with a key that fits, sends the security signal to the BCM, which sends the ignition signal to the PCM. The PCM, once the engine is started, either allows it to continue to run, or it discontinues PMD ignition pulse if the signal voltage is missing. It then commands the U1000 (means the BCM has an issue), and the P1626 (means the PCM hasn't received the ignition code from the BCM). This suggests the problem is the BCM or upstream to the ign. switch, or the BCM communication circuit in the PCM is open or failed. A corrupt radio security signal is a different DTC, and only applies if a foreign (security) radio is connected, that was not security-unlocked prior to removal from the previous vehicle (if the radio doesn't pair with the BCM, it fails, making stolen, locked radios useless). The system will not fail simply from a missing radio security signal.
The injectors could certainly be fouled, but not due to the plugged cat. The plugged cat may be the result of fouled injectors, however. Exhaust back pressure is minor, compared to combustion pressure.
Administrator
Something else that just occurred to me....
I take it you haven't tried a relearn of the lock cylinder. It's possible, and maybe more likely, that the BCM has rejected the correct code, due to all the time with power in and out, and perhaps an extended low voltage period. The relearn is a Key-On / Key-Off and timing procedure. I don't have the service manual for your truck, but I'm sure someone on the internet has had a talk about it.
Administrator
Administrator
Missy Good Wench ( Moderator)
I watched a video on bypassing the lock cylinder code.
Pretty simple
https://www.youtube.com/watch?v=ZRS6py8pyZs
What Maverick mentioned about the low voltage and power on and off thing.....
Myself I would bypass that bad boy.
A simple trick of adding a resistor of the correct value .
I would do the trick covered in the video....the resistors are CHEAP
The fella that did the video did not mention what wattage rating on the resistor..
I would grab a resistor of the correct ohm value in 1/2 watt rating....
If this gets the rig going the issue should not return....
Either the thing has lost it's brains or the lock cylinder is not giving the correct ohm reading...
Another case of over thinking the plumbing me thinks
Last edited by Robyn; 02-25-2022 at 18:45.
(1) 1995 Suburban 2500 4x4
(1) 1997 Astro
(1) 2005 Suburban (Papa Smurf)
THIS IS BOW TIE COUNTRY
Administrator
Not really. It's not complicated, generally very reliable, and easily corrected. There was a time, before this security measure, GM pickups were the most-stolen vehicles in CA. Simply pry off the column cover and push the rod. Gone in 12 seconds. The electric/electronic measure slowed it down, a LOT. Camry's and Accords were next on the list of the most-stolen. What happened? A few years later, they incorporated the same ignition security system.
Bypassing is fine, but it defeats the security system. Probably OK in most cases. The relearn process is free, and if it works, saves some effort, and it's probably good for another forever. If you bypass it, you still have to do the relearn, and it may or may not fail just as often for the same reason. If the code cylinder has failed, bypassing may be a cheaper option, but it's no more effective than the original. Anything short of removing the process from the PCM code will be essentially the same.
Last edited by DmaxMaverick; 02-25-2022 at 23:08.
Missy Good Wench ( Moderator)
I wondered about this.....If the pcm has a glitch and then does not like the resistor value....then the same issue all over again.
Glad you mentioned that Greg.....I thought about this after I posted on the video.
There must be a way to deactivate this system permanently ?????
Up in the great white north....probably not too much issue with a 1998 Burb getting stolen me thinks
(1) 1995 Suburban 2500 4x4
(1) 1997 Astro
(1) 2005 Suburban (Papa Smurf)
THIS IS BOW TIE COUNTRY
Enthusiast
Thanks a bunch everyone
I will try the relearn today,i should have time in my schedule over the weekend if i don't get to it today.
Holiday here yesterday otherwise i heard you can get chipped keys from the locksmith in the big smoke,couldn't follow up on it because of the day off all business were closed.
Fingers crossed that one of the relearns will fix the issue,or at least narrow it down.
When i ended up with the Burb i never thought i would be worried about anyone stealing it,i had it pegged as a rust bucket from SE Alaska.Seeing it's actually in nice shape maybe someone might want it in civilization.Planning on being in Vancouver with it so the theft deterrent may actually get put to the test there.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews
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