Build thread 5.3 W/6L80e in a 1986

[AJII]

None of those codes will keep the truck from running.

FPCM is something the newer trucks have that regulates fuel pump power to control fuel pressure.

 

[da_raabi]

It does seem strange that the truck plain dies, my thought being that there is an air/fuel issue. If the 02 fix does not help with the shut down problem, my next thought would be to investigate the fuel pump circuit(s) and make sure they are clean and solid, also if there is a way to keep an eye on your fuel pressure to double check the fuel pump, that might help as well.

Glad you were at least able to clean up ONE code!

 

[foamypirate]

Starting and dying also sounds a lot like VATS is still activated...

 

[Houston Ben]

Thanks for the replies!!

It does seem strange that the truck plain dies, my thought being that there is an air/fuel issue. If the 02 fix does not help with the shut down problem, my next thought would be to investigate the fuel pump circuit(s) and make sure they are clean and solid, also if there is a way to keep an eye on your fuel pressure to double check the fuel pump, that might help as well.

Glad you were at least able to clean up ONE code!

I checked the fuel pressure and it was around 55psi, I forgot to write down what it was and will have to borrow the pressure tester again. Thanks!

I am going back to the tuner to have him delete all the EVAP stuff do you think I should have him delete the "lost communication with fuel pump control module" code?? Also, what else should I check to see if he deleted besides the VATS??

Thanks again all, I am so ready to drive this thing!!

 

[Houston Ben]

One More thing, when I try to start it, if I pump the peddle it will rev but I have to pump it a bunch of times to try to keep it going, kinda like pumping an old school carb engine to get the gas in, any thoughts??

 

[da_raabi]

Definately get the VATS checked out. If thats not it my guess is it seems like a fuel issue, is the fuel pressure regulator working ok? Injectors nice and clean? Its not an old engine so I can't see either of those being an issue... Now if you could find someone with a professional OBDII reader they might be able to help get you some fuel/air mixtures etc while your running, that might help you narrow it down. If you dont know someone, I think the parts stores have them for under $100, and they can be handy to have around.

On that fuel control code, here are a couple sites with folks talking about it:

http://www.elcovaforums.com/forums/archive/index.php/t-41439.html

http://forums.chevyhiperformance.com/70/8982716/general-chevy-technical-discussion/u0109/

Heres a goody on yellowbullet:

http://www.yellowbullet.com/forum/showthread.php?p=6913774

...• U0109: Lost Communication With Fuel Pump Control Module.
These conditions may be caused by, but not limited to, any of the following:
• Chafed, damaged, pinched, open or shorted wiring.
• The terminal(s) for the High Speed GMLAN Serial Data Bus has or have backed out of the 16-way electrical connector to the automatic transmission.
• The terminal position assurance (TPA) lock in the transmission 16-way electrical connector is not fully seated.
• The High Speed GMLAN Serial Data Bus circuits are open or shorted to ground.
• Corrosion in a control module connector.
• Intermittent or poor connections in the inline connectors containing the High Speed GMLAN Serial Data Bus circuits.
• Water intrusion in a control module connector.

 

[Houston Ben]

Hi all,
Is the throttle body flap supposed to move when the ignition is in the ON position but not started? My flap seems like it wants to move when the gas peddle is pressed but barley budges, is this normal? There is also a high wine coming from somewhere on the engine when the ignition is in the on position??

any thoughts??

 

[da_raabi]

Hmm, I've been thinking about this since you posted, but I'm not too sure about it. Anyone with a running LS that can verify?

 

[HotRodPC]

Hi all,
Is the throttle body flap supposed to move when the ignition is in the ON position but not started? My flap seems like it wants to move when the gas peddle is pressed but barley budges, is this normal? There is also a high wine coming from somewhere on the engine when the ignition is in the on position??

any thoughts??

So where are all our LS guys??? Help a member out !!! I wouldn't know about this. Sorry

 

[Houston Ben]

Well, I got my PCM back from the tuner and what do you know......it started and stayed running!! I hooked up the PCM and turned the power, hit the pedal and I could hear the throttle body flap moving so I knew something was right. I turned the ignition and started right up and kept running. I don't know what he did as he didn't include any info in the package but it worked. SO EXCITED!!!!!

Now I just have to button it up and be done!!

Thanks for all your help guys!

 

[da_raabi]

Awesome! Glad to see it all worked out for you! I'd be really curious what he did to the PCM, I'm thinking he forgot something in there somewhere. I'm just glad he didn't screw up your motor! Hey if you get a chance, get a vid of it running, we'd all like to see it!

 

[Houston Ben]

Alright, here is some vid of it running

https://www.youtube.com/watch?v=JxCBf5ER50k

https://www.youtube.com/watch?v=dHZo8uDOKDQ

https://www.youtube.com/watch?v=WONDIfhAOiI

Lemme know what you think and thanks for all the help!

 

[da_raabi]

Dude. Yes. Lovin it. That thing sounds fantastic! I love the "Gets up to 80 real quick" - glad to see its workin good!!! Now tear up some tires and have fun!

 

[oneluckypops]

Dang sorry I just found this thread. I live just on the west side of Houston so if you have any more issues let me know, I would be willing to bring my diagnostic computer and anything else you might need and help you resolve anything else. (Even though I didn't get to modify the Wiring harness for you) lol

 

[oneluckypops]

Hey just watched your video's. Notice your using a GPS for the Speedometer. Are you wanting to hook the factory speedo up? I was just at the pull a part yard on 249 a week ago and they had the instrument cluster that was still in a 91 chevy suburban. Which would be the electronic speedometer.

Could you provide who you used for a tuning source for us? I am hoping it was someone local.