Just a heads up Don, when you disconnect the battery, the PCM may need to relearn idle and may run like crap and stall until it does...

I'd think that a flattened cam lobe would trip a misfire code, but anything's possible

 

Atomic
When I checked the fuel pressure it was at Idle and up to temp, it flickered 60psi +- 1lb anything above Idle it would jump between 65 and 58psi. and when I let it go back to idle it was back to 60.

Billy I thought of that and let it idle for 10 min the took it around a few blocks and back. No change then I disconnected the MAF.. sorry should have mentioned that.

Don

 

Hey Guys

Thanks for all the responses. I wanted to give a update.
Had a Comp leak down test today and the tech said 2 consecutive cylinders were a little low and its probably causing my rough idle thru 950rpm issues he is surprised its not throwing a code but he said it wasnt that low.

So i decided to go and load my gun on a LQ4 build and will be pulling the trigger soon on that. I already have an LQ4 with 68k on it I just want to start with a fresh setup.

Thanks.

Don

 

Hey
The saga goes on for this.
Today I got a new code and it started to run poorly after.
Maybe whats causing all the issues.
P0053 HO2s heater resistance bank1 sensor 1 (pcm)
2 days ago I put in my 3rd replacement for o2 bank 1 sensor 1.
If Im reading the description of the fault correctly, I have a short in the pcm!?
Ive had the wiring checked before and it was good and the voltage in the connector was also good.
The only welding I had done on the truck was back in 05 when I had my cat back exhaust made inst. If he didn't disconnect the battery could this have done this? And why dose it take almost 6years to show up?
I have a pcm from an 04 express van and I cant seem to get a definite answer if it will work on my 05. Any one know?
If not dose anyone know where I could get a pcm for my van at a reasonable price hopefully its out of an 05 van so I don't need to re flash it.

Thanks in advance

Don

 

Pop the valve covers off and make sure a valve spring isnt broken.

 

If you have a misfire I would ignore all those codes until you get the misfire fixed. Get a scan tool that will display which cups are missing. If they have spark you would need to do a balance test on injectors also. If those are good check compression. I think you said someone did, what was the results? Readings?

 

I am having very similar problems on an 04 tahoe. It keeps blowing the fuse for the heater circuits on the O2 sensors, and it doesn't let the trans shift right from time to time. I haven't verified it yet, but I am almost certain it's the pcm.

 

Jokeman
1 would that explain P0053 code
2 would the broken spring make some noise?

scooter
Ill get it back on the scanner to check for misfires
Just had the injector system serviced but didn't do a balance test.
I actually have a complete new intake manifold with all new sensors, tb, injectors, rails.. and I was going to put it on the motor I want to rebuild so I have a completely new engine.(I stared another thread labeled LQ4 mild build) look it up and add your 2cents
The Comp test results were cylinders 2,6 where low I didn't get a full report from him yet picked up the van after he had gone for the day.

Fastcount03
My fuel trims sometimes go in open loop after an hour of driving and it runs poor.
Let me know how you make out with it!

Don

 

Im sure you have checked your coils right?

 

no we didnt think of that we checked the plugs and they all looked the same, White.