Need help to keep engine running!

[Kiquee71]

I’m located in Orange County Ca. car is in Huntington Beach. Need someone to help get this engine running. Looking for someone to come to the shop and see why it won’t stay running. Reaching out to anyone that could help. Here is some info of engine and trans in question :


2009 LY6 6.0 liter engine ( 09 Chevy
Express 3500 ) stock internals w/ VVT
LS3 Intake with injectors
LS3 MAF sensor
LS3 Throttle Body
Stock LY6 MAP sensor
160 deg. Thermostat
GPI’s SS3 VVT Cam and valve train
4” cold air intake system
4L80E trans w/3600 stall converter
3.70 rear gears
26.7 diameter tires


E38 ECM & T42 TMC has been flashed to remove all
unnecessary stuff and not locked



Engine fires up for a few seconds then shuts down, no codes pop up. Fuel pressure is good. Need to get it to run and move on it’s own power and will worry about final tune later on the dyno.

[jlcustomz]

Running only a few seconds is almost always related to VATS module. Should have been removed from ecm. There are also add on vehicle anti theft bypass modules, which I have on my modded factory wiring harness.

[Kiquee71]

Running only a few seconds is almost always related to VATS module. Should have been removed from ecm. There are also add on vehicle anti theft bypass modules, which I have on my modded factory wiring harness.

Thanks jlcustomz As far as I know the VATS has been disabled and the anti theft also, but I have no way of verifying if that has been done. I’ve been dealing with a tuner with remote tuning using AutoCal, and its hard to do this cause I work and the car is at a shop so it makes it hard for me to be there and diagnose. Don’t really want to shop to mess with it either cause they charge by the hour and that could get pricey. They usually talk their customers into buy a new engine, ECM, harness etc to get away from troubleshooting these problems. I get it, but I don’t have deep pockets either. They also don’t have a go to tuner either. That’s what I’m looking for, someone to come in and hook up to the ECM and see what the issue is. Just to get it running. Know of anyone?

[Kiquee71]

Ok here is another question for anyone that is a tuner or anyone who know or use Efilive. I have the tune files for my car but don’t have the ability to check what has been removed, disabled, adjusted etc. I’m trying to find out if it’s in the tune, mechanical or electrical. I’m in the position of being the middle man from the shop to the tuner and it sucks. They ask what did he do and what did he do is not making things happen. Really looking for some help, advice or contact to someone. Thanks.

[rickpaw]

Were you able to check for codes?

Mine did the same thing (started right away, ran for a few sec then shut off). Code was showing MAF sensor error. Turned out I forgot to plug the unused vacuum ports on the intake.

[Kiquee71]

Were you able to check for codes?

Mine did the same thing (started right away, ran for a few sec then shut off). Code was showing MAF sensor error. Turned out I forgot to plug the unused vacuum ports on the intake.

Yes checked for codes but none came up. Checked for vacuum leaks, disconnected MAF and reconnected but no running. Starts for a few seconds shuts down. Trying to find someone that can help to cone by and diagnose, will pay for there time of course just want to get it running. Thanks rickpaw

[79 Camaro]

My .02 is since you have to tune it anyway and if it's moveable take it to the tuner of your choice and have them look into it. Might be something simple. Nothing worse than a shop that's not well versed in LS stuff spending hours getting nowhere.

[Kiquee71]

My .02 is since you have to tune it anyway and if it's moveable take it to the tuner of your choice and have them look into it. Might be something simple. Nothing worse than a shop that's not well versed in LS stuff spending hours getting nowhere.

You know 79 Camaro I’ve have been given that some thought too. Thanks

[Bugzilla]

Are you sure you have the MAF going in the correct direction? They normally have a little arrow showing the direction of air flow up by the plug.

[Kiquee71]

Are you sure you have the MAF going in the correct direction? They normally have a little arrow showing the direction of air flow up by the plug.

Thanks Bugzilla. When I built the cold air intake I triple check orientation of MAF sensor before I welded the housing bracket to the tube.

[Bugzilla]

Thanks Bugzilla. When I built the cold air intake I triple check orientation of MAF sensor before I welded the housing bracket to the tube.

No problem. I trouble shoot this exact stuff everyday so its right down my alley. Cant tell you how many times people think the arrow points towards the air filter. Did you tell your tuner what size tube you were going to run for the MAF? And did you also tell him the part number on the MAF that you are running? Do you know what operating system was loaded on the ECU? If its the same ECU that came from the 09 Express Van and your tuner didnt change out the MAF in the cal, that could be the problem. I am pretty sure the Vans use a different MAF than the typical cartridge LS3 style (assuming yours is part number 15865791). E38s in a way suck. Sometimes if you try to load on a different operating system, it causes all sorts of weird things to happen, even bricks the ECU sometimes. They are more like a year specific ECU that requires that exact year operating system.

Lastly, can you post a picture of your cold air intake? Something to where I can see the MAF?

[Kiquee71]

No problem. I trouble shoot this exact stuff everyday so its right down my alley. Cant tell you how many times people think the arrow points towards the air filter. Did you tell your tuner what size tube you were going to run for the MAF? And did you also tell him the part number on the MAF that you are running? Do you know what operating system was loaded on the ECU? If its the same ECU that came from the 09 Express Van and your tuner didnt change out the MAF in the cal, that could be the problem. I am pretty sure the Vans use a different MAF than the typical cartridge LS3 style (assuming yours is part number 15865791). E38s in a way suck. Sometimes if you try to load on a different operating system, it causes all sorts of weird things to happen, even bricks the ECU sometimes. They are more like a year specific ECU that requires that exact year operating system.

Lastly, can you post a picture of your cold air intake? Something to where I can see the MAF?

Yes I can, but when I get home. I’m leaving work now.

Just got home Sean. Yes I did give that info to the tuner meaning LS3 MAF, LS3 intake w/injectors, LS3 TB, 4” intake tube etc. As far as what operating system he gave me I’m not sure, using AutoCal and he said he made some calibration changes for start up. He did mention something like it could be a wiring issue too. Had original harness redone so not sure I want to have the shop start digging into that mess racking up hours. So I decided to get another brand new harness made with all the extra stuff included. Keeping fingers crossed. See I’m the middle man between the shop and tuner and it sucks. I see your in So Cal, any chance close to Orange County. Anyways here is the photo you asked for. Thanks for reaching out and helping out.

[Kiquee71]

Posted that info you requested Bugzilla

[Bugzilla]

Thanks for the pictures! Greatly helps. Ok so yes, like you said the MAF is going the right direction. Its in a good spot on your tube as well. The one other line you have coming off it, what does it go to? One of the valve covers? If so, I typically like to see those plumbed in before the MAF. 2 things for you to try. First one, unplug the MAF and try to fire it up. It will take a couple cranks before it defaults to speed density mode. If that doesnt work, plug it back in and try to make it run on brake cleaner or starting fluid to see if it will stay running that way. So you also changed the intake and everything over. Were the injectors new or something that was a used take out? There could be a chance that they are gummed up.

You said you had the harness redone. There is a little jumper harness that typically goes into the cam sensor and VVT sensor and pops out down by the side of the passengers side of the balancer, are you still using that jumper or do your wires plug directly into the sensors? If they got rid of the jumper harness, there are 2 cam sensor wires that need to get swapped around. Not sure if whoever did the harness would have known or not. But that would cause the same start and die issue. I can get you a picture of said jumper harness if that would help.

I am out in San Bernaghetto. I would say about an hour from OC.

[Kiquee71]

Thanks for the pictures! Greatly helps. Ok so yes, like you said the MAF is going the right direction. Its in a good spot on your tube as well. The one other line you have coming off it, what does it go to? One of the valve covers? If so, I typically like to see those plumbed in before the MAF. 2 things for you to try. First one, unplug the MAF and try to fire it up. It will take a couple cranks before it defaults to speed density mode. If that doesnt work, plug it back in and try to make it run on brake cleaner or starting fluid to see if it will stay running that way. So you also changed the intake and everything over. Were the injectors new or something that was a used take out? There could be a chance that they are gummed up.

You said you had the harness redone. There is a little jumper harness that typically goes into the cam sensor and VVT sensor and pops out down by the side of the passengers side of the balancer, are you still using that jumper or do your wires plug directly into the sensors? If they got rid of the jumper harness, there are 2 cam sensor wires that need to get swapped around. Not sure if whoever did the harness would have known or not. But that would cause the same start and die issue. I can get you a picture of said jumper harness if that would help.

I am out in San Bernaghetto. I would say about an hour from OC.

- that hose goes to the passenger side valve cover, you are correct.

- we have tried cranking it over without the MAF sensor plugged in, did that for about 3 cranks. Did the same thing, it will fire for a few seconds then die with a little backfire.

- as for the intake as of right now I’m not sure it was new or used take off. Will have to check my records. I believe it was new, cause didn’t notice any oil inside the intake or runners.

- don’t know if the shop tried that starting fluid thing, but will be going to the shop and bringing some with me on Friday.

- the jumper you speak of is still intact and runs done the drivers side of timing cover. The guy who did the harness was aware of it being a VVT engine.

Ok not very far from me, I’m in Buena Park but the car is HB. You wouldn’t by any chance have EfiLive or HPTuner’s? I was hoping to find someone to hook up to it to see what’s it doing? Will pay for there time too? Really don’t want to spend money on buying stuff if those weren’t the issue, know what I mean. Thanks again for helping.

[Bugzilla]

- that hose goes to the passenger side valve cover, you are correct. You can try plugging it but I doubt its the issue

- we have tried cranking it over without the MAF sensor plugged in, did that for about 3 cranks. Did the same thing, it will fire for a few seconds then die with a little backfire. You may need to crank it more. If it threw a MAF code, then you cranked it enough

- as for the intake as of right now I’m not sure it was new or used take off. Will have to check my records. I believe it was new, cause didn’t notice any oil inside the intake or runners. If you can get me your injectors, I will put them on the flow machine to make sure they are all firing and flowing right

- don’t know if the shop tried that starting fluid thing, but will be going to the shop and bringing some with me on Friday. Try and let me know. This will tell us if its a fueling issue or not

- the jumper you speak of is still intact and runs done the drivers side of timing cover. The guy who did the harness was aware of it being a VVT engine. Ok good

Ok not very far from me, I’m in Buena Park but the car is HB. You wouldn’t by any chance have EfiLive or HPTuner’s? I was hoping to find someone to hook up to it to see what’s it doing? Will pay for there time too? Really don’t want to spend money on buying stuff if those weren’t the issue, know what I mean. Thanks again for helping. That I dont have. I will in a few months when I swap out the engine and ECU in my Bug. I have access to a Tech2 which might help but wont say whats been done. Just can read all the live data and stuff. I will have to see when I am going out your way next. If its in the near future, I can stop by and take a look at it.

[Kiquee71]

- that hose goes to the passenger side valve cover, you are correct. You can try plugging it but I doubt its the issue

- we have tried cranking it over without the MAF sensor plugged in, did that for about 3 cranks. Did the same thing, it will fire for a few seconds then die with a little backfire. You may need to crank it more. If it threw a MAF code, then you cranked it enough

- as for the intake as of right now I’m not sure it was new or used take off. Will have to check my records. I believe it was new, cause didn’t notice any oil inside the intake or runners. If you can get me your injectors, I will put them on the flow machine to make sure they are all firing and flowing right

- don’t know if the shop tried that starting fluid thing, but will be going to the shop and bringing some with me on Friday. Try and let me know. This will tell us if its a fueling issue or not

- the jumper you speak of is still intact and runs done the drivers side of timing cover. The guy who did the harness was aware of it being a VVT engine. Ok good

Ok not very far from me, I’m in Buena Park but the car is HB. You wouldn’t by any chance have EfiLive or HPTuner’s? I was hoping to find someone to hook up to it to see what’s it doing? Will pay for there time too? Really don’t want to spend money on buying stuff if those weren’t the issue, know what I mean. Thanks again for helping. That I dont have. I will in a few months when I swap out the engine and ECU in my Bug. I have access to a Tech2 which might help but wont say whats been done. Just can read all the live data and stuff. I will have to see when I am going out your way next. If its in the near future, I can stop by and take a look at it.

Ok I will get back to you Friday after I’ve done the starting fluid thing and checked if injectors were new or used. Thanks.