ericwilloughby

Help please

Engine build #1: Pulled my turbo LS2 down for a re-ring/comp cam. It had 2 bent ring lands so it got 2 new pistons, 8 sets of gapless rings. Long story short is it will just barely run at all. Has a HARD DEAD miss and will not go over 3500 WOT in park. The passenger bank seems to be ok but the drivers bank is making only about half the heat it should, #7 cyl almost none at all.

Changed cam sensor, crank sensor, CPU, plugs. Towed to dealer, they wouldn't look at it. Kept trying to run it. DESTROYED pistons, rings, bearings with what looks like a pound of sand in the oil. I assume it came from fuel not burning....

Engine build #2. Bored .010, 8 new forged Manley pistons, Total Seal gapless rings $$$ 1,000.....Compression was 180-190 on all cyl. Same problem, dead/weak drivers bank. Thought the Comp cam/patriot gold springs might have been leaving the valves hung open/floating even at idle. Put stock cam back in. Keep trying to run it. DESTROYED EVERYTHING. By the time it ran 30 min I had 30, 30, 50, 120 driver side, 180...passenger side compression. Lots of oil in the intake and turbo charge pipe. The grit/sand in the oil might have ruined the turbo bearings. Took turbo OFF.





After I honed the varnish off....this was underneath






Engine build #3: Bored .030, 8 more forged Manley pistons, Total Seal gapless rings $$$ 1,000.....Same problem, dead/weak drivers bank.
Running it as little as possible this time.

Things I've tried/where I am now: Put stock cam sensor and crank sensor back in today. 4 sets of plugs. Switched drivers coil bank with passengers coil bank. Tried 4 different tunes. Stock cam, lifters, everything stock except valve springs. I checked the valves for leakage with water, machine ship did also, same method. Compression is 180-190 on all cyl for now. Started out that way last time also.

Switched injectors back to stockers on the first engine build. Went back to Siemens #60's. Pulled fuel pump relay, put propane torch nozzle up to throttle body idled engine on propane with no gasoline. Didn't get any better, still hard miss. That rules out a fuel problem completely I believe. During compression tests I plug all 8 plugs up and watch them spark. Spark looks good to me. O2 wiring is fine. They may still have oil on them but I've been running it in open loop. It doesn't help. Misses when its cold also. I don't think o2's can cause a problem cold or in open loop??

It acts like the firing order is wrong. How is that possible?

427

iTrader: (3)

Is the coil harness on wrong?

Kurt

ericwilloughby

Coil harness? It'll only plug in one way. What do u mean?
I just checked. The white plug will only go in one way. Tabs and locks.
Same for each individual coil. I've never had them apart. I just unplug the white/main and take the whole pack off.

It is acting like the firing order is out. But I don't understand how it would be possible to connect it wrong.

LS1MCSS

iTrader: (18)

Do you have power to the coil pack on the dead side?

djfury05

iTrader: (30)

You need to check for proper order of coil harness plugs. Here is the order.

Driver side bank from front to rear is: Purple, Blue, Dark Green, Red

Passenger side bank from front to rear is: Red/White, Dark Green/White, Light Blue/White, Purple/White

You are looking for the signal wire on each coil plug when checking for the correct order.

ericwilloughby

Yes, I have seen all 8 plugs firing while I was doing compression test.

I have never had the pins apart or the coils off the rails so I doubt they can be hooked up wrong.

Now that I've got the stock cam back in I think I will try the new computer again.

ericwilloughby

I put the new PCM back on and did an entire rewrite. No ******* better. I'm beyond sick of throwing thousand after thousand after thousand in the trash just trying to get this POS to run.

I also checked the 3 main grounds, drivers head rear, passenger head front, and A/C compressor. All good. Also checked the wiring on the coils. Just as it should be.

Why does this thing act like the firing order is incorrect or the timing is 25d too low?

djfury05

iTrader: (30)

So you actually made sure each connector with the correct colored signal wire was plugged into the correct coil? Or you just looked to see if all the connectors were together?

ericwilloughby

Check them all. The same as your chart except there is no /white that I can see.

I.E.





With the new ECM I'm getting these codes now. Gotta find out what they mean.


[ECM] P1677 - Driver 4 Line 7 (Old) (History) (Current) (Immature)
[ECM] P0315 - Crankshaft Position System Variation Not Learned


Continuous Tests
Misfire: Complete
Fuel System: Complete
Comprehensive Component: Complete

bww3588

iTrader: (49)

With the crank sensor codes, my guess would be your reluctor wheel slipped or something. Try pulling the crank sensor and watching the reluctor wheel while someone turns the engine over by hand. You should be able to tell if it's bent.

ericwilloughby

Chris at hpt said that code is because I installed the "new" PCM and must take the car to the dealer to have the PCM learn the "variation"


looks like GM re-used this code on newer vehicles.

P1677 - Immobilizer Deactivated

Atomic

iTrader: (37)

You really did 3 rebuilds and still havent got it to run? Holy **** man...

Are you sure the cam is properly lined up with the crank? Try new plugs, stock injectors, and stock pcm. If it doesnt work, then dont sit there and try it for 30 minutes! Test the wiring harness going from the injectors and coils to the pcm.

Gray Ghost Silverado

iTrader: (1)

I saw this post on the HPT forum. Gonna do some digging and see what I can find. It sounds to me like the injectors are hanging wide open. Do this, compare your stock HPT file versus the new HPT file for your current time. Go to both the engine fuel and spark sections and look at the control patterns and see if something has changed. They shall either be listed 1-4 or A,B,C, or even D.

cam75w/ls1

iTrader: (2)

Did something get sandblasted by chance? I sandblasted a intake on an old school smallblock one time and washed it. Still had glass beads get in the rings and ruin them. The picks look the same as what my motor did.

ericwilloughby

I checked the voltage and ground wires at the coils, power is good and steady. I even put a test light on the signal ground, brown, and it is good too.

I have spark, I've seen it. I also get heat at the exhaust. Damn thing just has no power and shakes the doors with a miss.

As per fuel, I've shut the fuel pump off and let it idle on the propane coming out of my tourch nozzle. Still missed like a mo fo.

It's going to another dealer on Mon.

Gray Ghost Silverado

iTrader: (1)

Sounds like the firing order got changed somehow, which can be done easily if you flub up in the A-B section firing command with HPT.

PM sent.

ericwilloughby

Well I guess my next step is to put a timing tape on the balancer rig a pointer and check the timing of each cyl. I think it has to be a spark timing problem.

I think I'll pull the fuel pump relay and run it at higher rpm on propane to make sure it isn't a stuck injector or fueling issue first.dum

ericwilloughby

I'm not familiar with that tab. I didn't think it was possible to change the firing order. I've tried 4 known good tunes including the oem. Wouldnt that have corrected the problem you suggest?

Thanks for the help. Ill send the tune in the morning when I get off work

bww3588

iTrader: (49)

If you think it's an injector, try swapping injectors and see if the problem moves.

Gray Ghost Silverado

iTrader: (1)

If you flashed a totally stock file into it then GET RID OF THAT PCM. Something is wrong with it. Otherwise you might wanna check your harness location for injectors. From the head-off picture it looks like those cylinders are getting PLENTY of fuel, so I'm betting timing. Maybe you have a computer that is designed for a 58X reluctor wheel and your crank is 24X???

Hey that may be exactly what happened if I'm thinking right!