427 L92 a4 GTO issue

[10secvette]

I know you may have checked it but is your reluctor wheel welded to the crank or pressed on? We have seen a couple fail when not welded. Turn over when static but float when running giving wierd timing numbers as the reluctor slips and speeds up.turn the engine over and apply a bit of a load to the reluctor to double check it or get a dual channel trace and check both cam and crank at the same time.
Hope this helps nothing worse than those annoying faults.
Cheers Shane

I believe Shane may be the winner. I'm pulling the engine this week to tear it down and check.

[shane]

No need to pull the engine just pull out the crank sensor out of the block and look in ther if you can, get someone to bar over the engine slowly and push against the reluctor wheel see if it slips...

[10secvette]

No need to pull the engine just pull out the crank sensor out of the block and look in ther if you can, get someone to bar over the engine slowly and push against the reluctor wheel see if it slips...

Will do, I put it on the lift last night. It's not free wheeling, it appears to have "shifted/slipped" on the crank losing it's index. I put a timing light on it yesterday, it's about 13' off actual vs. what's commanded.

BTW, mine was pressed on. I know when they balanced the crank it was removed.

[10secvette]

It's out and the engine is apart. Crank is at the machine shop getting checked. TC is going back to Yank to be restalled. May as well since it's all apart.

[gmh308]

Will do, I put it on the lift last night. It's not free wheeling, it appears to have "shifted/slipped" on the crank losing it's index. I put a timing light on it yesterday, it's about 13' off actual vs. what's commanded.

BTW, mine was pressed on.

I know when they balanced the crank it was removed.

Wonder if they re-installed it using the correct indexing tool, or did it by eye?

And if they simply cold pressed it on vs heating and shrink fitting it and the shrink fit was stretched.......?

[10secvette]

Wonder if they re-installed it using the correct indexing tool, or did it by eye?

And if they simply cold pressed it on vs heating and shrink fitting it and the shrink fit was stretched.......?

Machine shop called, around 30' off. Amen we figured it out.

[joecar]

30° off... wow... post pics of the repaired crank.

[10secvette]

30° off... wow... post pics of the repaired crank.

Will do!

Thank you to everyone that shared thier ideas and helping!!!!

[10secvette]

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Re-indexed and tacked on.

Hopefully the wife and kids give me the time to assemble the engine today.

[98 tigershark]

I have a 98 C5 with a L/92 427.
A very nice motor indeed. The overheating problems are familiar to me as well as the lose of power and reduced power and reduced power mode. When you reflash the PCM and it is almost finished, look at the readout at the bottom of the speedo.
See when the tun is done loading if the read out says reduced power mode. If so, you have to re flash the tun until it is gone. THe radiator on my car is to small also. I think the cats also may go over the O2 temp limit of 1279 degrees. These are pretty high performance motors and I think the O2 sensors can be fouled very easy and the cars go into reduced power mode when reflashed quite often. The AIT temp sensor is also very important to move away from these heat creating motors. Loading up is also a constant problem and percolating fuel in the fuel rail also is a constant problem (a return line helps). Another major important issue to watch out for is is to make sure the engine builder or installer made the oil pick up tube adjustment when they installed the pickup tube and windage tray (if you had to drop the windage tray about a half inch the pick up has to be pushed back up that exact amount or else you will hemorrhage oil and it may go into the intake as well. Stock stroke 3.62, new stroke 4.1 so 4.1-3.62=.48in so space the windage tray and then push the pick up up this amount if not done already). These motor also have crank pressure things to watch for so you do not damage the motor. I do think exhaust temp, all cooling issues and breathing issue are important to address prior to the build, as these motors are hungry for air and a good flowing exhaust and a good cooling system. I have had the combo for around a year.
Look into fuel starvation to the motor as according to my math the LS7 injectors are to small for my combo as well as the fuel pump out put (I get fuel starvation at 5,900 rpms in 1st, 5,600 in 2nd, and 5,500 in 3rd.
Also any cooling things for the tranny fluid and oil are equally important
98 tigershark

I need some help.

I put together a 427 L92 for my 2005 GTO. It was tuned and put down 490 rwhp unlocked through a ss3600 tc. The car ran fine for a week. I took it to the track and ran a 11.60@ 120 on the first pass. I let the car cool down a touch and on the second pass it layed down a 12.55 @105. It had a rough idle while driving back to the pits. The car left hard but layed down at 1/2 track. While looking the car over in the pits, I discovered a hanging ground wire off the drv. side head. I figured I had found the problem. Put the ground back on and no improvement. At this point the car would hardly idle, and was backfiring throught the intake. We towed it home and here we are today.

I have changed or tested all the sensors, changed plugs, plug wires, coil packs, throttle bodies, intakes, etc. At this point it's idling again, but when in gear with the traction control on, while steeping on the brake pedal, the pcm pulls timing to -3 to -5 degrees almost stalling the engine. It only does this while in gear and with te traction control on. With traction control off, the car is fine so to speak. It lacks power, but I think a retune is in order.

While driving to day, it was o.k. with the tc off, but towards the end of my 15 mionute ride, it was loading up and poppping through the intake agin. I am stumped.

Tune and log available to email. I have no clue how to attach.