Terrible pinging at operating temperature
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
Originally Posted by kalister1
The timing on a LT1 is set when the Opti-Spark is installed, it could have been installed wrong?
That's what I'm afraid of. The shop I used came as pretty reputable. However, it turns out they are butchers. I just got the car back, and I've already found like 4 vacuum leaks after looking as suggested. They even put an EGR line with a hole in it back in!!
I had a shop do it because I've never built a SBC before. I figured the convenience of having "professionals" do it outweighed the experience coupled with the possibility that I could screw it up. Seems I may be tearing into her in any case. Hopefully when I call Bryan at PCM4Less we can figure something out. It really blows me away that it seems that outside of PCM tuning the timing is completely unadjustable.
Here's hoping for the best
-DM
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Originally Posted by DarkMatter
Actually, I was going to give you guys a call tomorrow afternoon. I put about half a tank of 100 octane in and she's still pinging bad.
I was going to ask on the phone tomorrow, but hopefully you'll see this now. What kind of data reader can I use to connect to the PCM? I purchased an OBD-II version today, but it tells me It can't connect.
Thanks in advance.
-DarkMatter
I was going to ask on the phone tomorrow, but hopefully you'll see this now. What kind of data reader can I use to connect to the PCM? I purchased an OBD-II version today, but it tells me It can't connect.
Thanks in advance.
-DarkMatter
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Originally Posted by DarkMatter
Nope. about 8 gals of 100, to 12 or 13 of 93 octane.
PS The Kb pistons are hypereutectics, right? MAN, BE CAREFUL WITH THE PINGING!!!! Those things are known for doing some UGLY stuff if the tops get what THEY call "superheated". ESPECIALLY if the top ring gap is on the tight end of the spec.You dont even want to know.
Last edited by edcmat-l1; Sep 1, 2006 at 10:51 AM.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
Originally Posted by edcmat-l1
That still shoud be enough for a 12:1 motor. not saying yours is higher comp. Just saying thats sufficient octane to run a motor with much higher comp. than yours is supposed to have.
PS The Kb pistons are hypereutectics, right? MAN, BE CAREFUL WITH THE PINGING!!!! Those things are known for doing some UGLY stuff if the tops get what THEY call "superheated". ESPECIALLY if the top ring gap is on the tight end of the spec.You dont even want to know.
PS The Kb pistons are hypereutectics, right? MAN, BE CAREFUL WITH THE PINGING!!!! Those things are known for doing some UGLY stuff if the tops get what THEY call "superheated". ESPECIALLY if the top ring gap is on the tight end of the spec.You dont even want to know.
I haven't even been driving the car. As of right now she's a driveway queen. Think I should drop the oil and check for extra metal beyond normal break-in wear??
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Originally Posted by DarkMatter
I haven't even been driving the car. As of right now she's a driveway queen. Think I should drop the oil and check for extra metal beyond normal break-in wear??
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
Was busy all day digging in forms for concrete in the yard. That and battening down some stuff for Ernesto (Who's blowing through here now). Nothing new with the car. I fired off an email to Bryan at PCM4Less. Hopefully he can shed some light on this.
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Originally Posted by DarkMatter
Was busy all day digging in forms for concrete in the yard. That and battening down some stuff for Ernesto (Who's blowing through here now). Nothing new with the car. I fired off an email to Bryan at PCM4Less. Hopefully he can shed some light on this.
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Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
So far he's just been about as much wind as my mother in law screaming about her son. A good amount of rain, but nothing torrential. I'm still glad I tucked everything low. Better safe than sorry.
-DM
-DM
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Have you checked the ignition control module and the coil? More so the ignition control module, they can cause issues when they get hot and have abit of age on them. By the sound of some of the things you have said here, it could be lots of things though!!
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
Originally Posted by Casethecorvetteman
Have you checked the ignition control module and the coil? More so the ignition control module, they can cause issues when they get hot and have abit of age on them. By the sound of some of the things you have said here, it could be lots of things though!!
I performed the ICM tests as per the Helm. It seemed to be performing corrctly. But of course, the tests are done while cranking, engine off. You think it's possible that as the ICM heats up, it's faulting?? Short of buying a new ICM to compare, is there another way to test it's hot operation??
Thanks for chiming in.
-DM
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Im in Australia so not sure of the place you can take yours for testing, but certainly as they heat up they can cause a problem if they are on the way out. (If you get it tested, make sure they keep testing till it gets hot, ive heard alot of people state 10 test cycles, if its heat related, no sense testing it stone cold!!) So if its never been replaced, try pulling it off and having a look at it, make sure the surface between the module and its heatsink are nice and clean, apply some new heat transfer compound if they are not clean or if there is none there. Since the engine has been all apart, and the module resides on the front of the right hand head with the coil, there is every chance the people doing the work may have put it back together without any termal transfer compound. (however unlikely unless they changed the coil or did something with that assembly)
Have a look and see what it turns up.
Have a look and see what it turns up.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
Although no timing adjustment is possible with the LT1, is it possible to check the timing using a light? If so, would it revolve around the cast arrow on the balancer, or would I have to try and line up the hub itself?
So far I've fixed a few vacuum leaks, and more than likely ruled out EGR malfunction.
Thanks again in advance
-DM
So far I've fixed a few vacuum leaks, and more than likely ruled out EGR malfunction.
Thanks again in advance
-DM
Safety Car
Joined: Apr 2004
Posts: 4,532
Likes: 7
From: Lahaina Hi
At the front of the intake pass side manifold intake.I would check to see if the map sensor is sealing to the intake .I would also check the 3 way valve on the pass side on the intake to see if one of the 3 vaccum lines are not broken.
You cant set your timing.You have a smart learn computer and if it is not taking out the ping maybe you got the computer wet or the knock module in the computer went bad.I installed an Lt4 module in my 94.
Clean all the conectors these cars crode the plugins real easy.
It also helps to know what rpm's itis pinging at and make sure the engine is not overheating.A plastic bag did mine in .Mine started pining
and slowing down no acceleration .Looked under the car at the radiator after I noticed it was hot and a plastic bag was stuck in the radiator.
Yes mine pinged like crazy and I had to replace the coolent sensor to get it to stop.The 280 deg took out the coolent sensor.I think it had been overheated before I got I t and the previous owner might had got i it hot to many times.
You cant set your timing.You have a smart learn computer and if it is not taking out the ping maybe you got the computer wet or the knock module in the computer went bad.I installed an Lt4 module in my 94.
Clean all the conectors these cars crode the plugins real easy.
It also helps to know what rpm's itis pinging at and make sure the engine is not overheating.A plastic bag did mine in .Mine started pining
and slowing down no acceleration .Looked under the car at the radiator after I noticed it was hot and a plastic bag was stuck in the radiator.
Yes mine pinged like crazy and I had to replace the coolent sensor to get it to stop.The 280 deg took out the coolent sensor.I think it had been overheated before I got I t and the previous owner might had got i it hot to many times.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
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From: Location Location
I imagine this is the "3-way valve" you mention? One of the fittings is snapped off in the boot on the manifold. Is it a dealer only part?? Do you have a rough idea of what they cost?? I'm sure they can't be too expensive. It also looks to be partially melted. I guess that's never good.
-DM
-DM
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Originally Posted by DarkMatter
Although no timing adjustment is possible with the LT1, is it possible to check the timing using a light? If so, would it revolve around the cast arrow on the balancer, or would I have to try and line up the hub itself?
So far I've fixed a few vacuum leaks, and more than likely ruled out EGR malfunction.
Thanks again in advance
-DM
So far I've fixed a few vacuum leaks, and more than likely ruled out EGR malfunction.
Thanks again in advance
-DM
Safety Car
Joined: Apr 2004
Posts: 4,532
Likes: 7
From: Lahaina Hi
You should be able to get the valve at napa.I get mine their ,I go through about one a year.
Remember this is just the starting point.The plastic on these cars suck.
Don't forget to check the electrical connectors for rust and what not.
Take your time when pulling apart the electrical connectors you don't want to break the plastic piece when you lift up on it.I use a feeler gauge and slide it under the connector lock.
Drive the car and make sure everything works cruise control,lock up converter,A/C and so on .
One problem at a time .
Let us know what your engine temp is.
Remember this is just the starting point.The plastic on these cars suck.
Don't forget to check the electrical connectors for rust and what not.
Take your time when pulling apart the electrical connectors you don't want to break the plastic piece when you lift up on it.I use a feeler gauge and slide it under the connector lock.
Drive the car and make sure everything works cruise control,lock up converter,A/C and so on .
One problem at a time .
Let us know what your engine temp is.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 855
Likes: 0
From: Location Location
H41: Ignition control circuit - open circuit. I pulled the ICM off to inspect it for cracks or other deformation of the module casing. It was HOT!! I mean 120+ C hot. Just for sh*ts and giggles I used an old kitchen probe thermometer to check. Should the ICM get this hot? I'm not sure of the specs of the unit. Is it designed to run like that?? I can't remotely see how temps in that range haven't been killing this thing.
Does anyone know the thermal specs for the unit?
TIA
-DM
Does anyone know the thermal specs for the unit?
TIA
-DM