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Discussion Starter · #1 · (Edited)
My car starts missing at wot going into 3rd gear. When idleing, it starts missing just above 3000rpm. I changed the plugs, 02 sensor at the track because that was what i had to work with at the time. Still missed. then I changed the coil pack, and still doing it. Then I unplugged the mass air flow sensor to see if it would stop missing thinking the computer would put a default reading in for the mass airflow sensor. still missed. Then, I started getting false knock real bad. 34 degrees.(@ idle) So I plugged the mastertech in(scantool), and it showed no knock. I checked the wiring to the scanmaster and all was fine. Then when I brought the rpms up, I started hearing a pinging noise from what sounded like the turbo. It started whistling funny then would make a funny noise and start cutting out again. Almost like it was overboost or something. All that in park at about 3000 rpms or so. I unplugged the ecm wire and plugged it back in, started it up, and the false knock went away. When I was at the track, the 02 millivolts were reading really high when I know it shouldnt have been because I kept taking fuel pressure down, and the numbers would stay the same(over 900) and half the time the scanmaster wasnt recording the numbers from my run. so I thought maybe a computer problem or something. Anyways, I finally got code 42 to show up. I was going to change the ign. module, but I dont want to keep throwing parts at the thing without some help from you guys. It does do this with both of my chips, so thats not it. Maybe you know something to try I dont. sorry for how long this is. Thanks in advance.
 

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first, you need to check and see what is causing the noises. The turbo should not be making any noises, so you can examine the shaft and make sure it is okay....If it is making noise, then it can cause the computer to do things to the timing...

You can check the cam sensor as I suggested here...as well http://www.turbobuicks.com/forums/showthread.php?t=53071

Beyond that...the usual...crank sensor? Is it clearing all three blades properly.

Is the nut tight on the balancer so it cannot wobble?

Does the coil ohm out properly?

Is the module melted when you pull the coil off so you can see the module?
 

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Discussion Starter · #3 ·
O.K. I changed the ign. module and it is still doing the same thing, and then I still got code 42 show up. Also, I am getting between 24 and 32 degrees of knock according to the scanmaster, but the mastertech is showing no knock and is showing spark advance. I dont get it. why am I getting that much false knock showing up. I trust the mastertech over the scanmaster. I checked grounds but I still have yet to check cam sensor, crank sensor. But I dont understand why it would throw code 42 right after it starts cutting out, and it end up being the cam sensor. shouldnt I get code 41 for that. Also, the Ats reading is showing nothing, just three lines across the screen. I know that has nothing to do with the miss, but shouldnt it always show a temp. Could it be the ecm. I pulled it out and tapped on it with my hands to check for a cracked circuit board or something while I watched the mastertech. All seemed fine. I'm about ready to take the radiator cap off and drive a new car under it. :confused:
 

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code 42 was probably caused by the new module. Was it an aftermarket one?

A screwy cam sensor often does not throw a trouble code.

Why is the car showing such high o2? If they are really that high, that can lead to rich detonation.

I think I would start by trying to find the source of any noises, plus why the o2s are off the scale.
 

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Discussion Starter · #5 ·
The o2's arent off the scale any more. That was at WOT while going down the track. at idle it is bouncing around 400 or so. But then again, I havent driven it since I trailered it home from the track. And about the noise, it wasnt extremely violent or anything, it was doing it when the car was being brought up in rpm, and cutting out. What am I supposed to do, rip the turbo apart. I checked the rod, the hoses, and the y connector. I dont see how I can diagnose that. Also, I got code 42 before I changed the module also. to check the cam sensor, do I start the car, then disconnect it and bring the rpms up to see if it still cuts out? Thank you for your help Steve.
 

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Discussion Starter · #6 · (Edited)
Ign. module

The module was an ECHLIN from Napa. I couldnt find a Delco anywhere. Not even in their warehouses at the time. They matched the Delco price. I get all parts at cost in that my dad runs a repair shop. I did disconnect the ecm wire to clear all codes after I changed the module.
 

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What am I supposed to do, rip the turbo apart
No, what you are supposed to do is to use some BRAIN! When you take the hose off, or the hard pipe, between the MAF and the turbo inlet, you expose the end of the turbo shaft, and the blades in the compressor inlet. At that point, it is very simple to put your finger on the end of the shaft, and see if there is any "slack" and in which direction. You can also look at the turbo blades, to see if they have hit the housing.
 

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Discussion Starter · #8 ·
Cam sensor

I started the engine, unplugged the cam sensor right away and got some heat in it. Then brought the rpms up to around 3000 as usual and it still misses. So Ill cross that off my list. To check crank sensor is it the same routine? Where is it located?
 

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Ormand said:
No, what you are supposed to do is to use some BRAIN! When you take the hose off, or the hard pipe, between the MAF and the turbo inlet, you expose the end of the turbo shaft, and the blades in the compressor inlet. At that point, it is very simple to put your finger on the end of the shaft, and see if there is any "slack" and in which direction. You can also look at the turbo blades, to see if they have hit the housing.
Not sure it had to be that harsh... :(


IMHO... :sw:
 

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Discussion Starter · #10 ·
Ormand said:
No, what you are supposed to do is to use some BRAIN! When you take the hose off, or the hard pipe, between the MAF and the turbo inlet, you expose the end of the turbo shaft, and the blades in the compressor inlet. At that point, it is very simple to put your finger on the end of the shaft, and see if there is any "slack" and in which direction. You can also look at the turbo blades, to see if they have hit the housing.
Look, sorry about the smart ass comment on the turbo. I am just getting very frustrated with this car right now. I do greatly appreciate any help and I think that that comment might have been taken the wrong way.
 

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The fact that you changed ign modules and that you're getting screwy readings makes me thing maybe something happend to one of the connectors on the module harness when you put it back on. Go ahead and pull that back off and check to make sure all of the pins looks ok and are clean. I had a bad connection there once that caused me to believe something was screwy with my ecm. Check your CCI fuse and ECM fuses to make sure they are tight and the pins are free of any corrossion. It's something you can do easily. As far as the noise check the turbo like was mentioned. :wink:
 

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Have you checked the oil to make sure it has no water in it? I am hoping you don't have a blown head gasket.

A code 42 http://www.vortexbuicks-etc.com/code_42.htm means that the ignition module is not handing over timing control to the ecm after cranking the engine.

What I don't remember is how much timing the engine is seeing when one has a code 42. I only recall that the module is providing the timing and it is not changing. Car won't run very good on a code 42. That is the reason I hope you did not blow a hg.

Now, why do you have a code 42. Use the link above to go thru the factory trouble shooting routine. Normally, it is a bad module. But, it can be a bad connection between the module and the ecm, or, it can be a bad ecm.
Don't be driving the car until you can fix the cause of the 42.

After you installed the module, did you clear the code by disconnecting the orange battery wire under the hood for a moment.

Sometimes aftermarket modules will not work correctly, and, that can also be a problem the further confuses the situation.
 

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Discussion Starter · #13 ·
Steve, I did spray the CORRECT kind of cleaner on the connector and let it air dry and shook it off when I changed the module. I shined a flashlight in the connector to make sure everything was o.k. and cleaned out. I will do it again to make sure. I did also disconnect the orange wire to clear any codes before I started the car again. The car did have a somewhat similar problem a couple years ago and it turned out to be the mass airflow sensor. Is that even a possibility. I dont know how to check that though. One thing I noticed also, is that one of the injector o-rings may be bad. I noticed that oil may have blown by and out through the injector o-ring. But it is only a tiny little bit. I wouldnt think that would cause all these problems. Because I doubt it is spitting oil out until under full boost at WOT. I was trying to figure this out on my own to save some money, but I may just leave it at the shop for them to look at monday. I did pull the dipstick out and the oil looked normal.
 

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Do you still have a code 42, or not? :)

If you do, the car will not run correctly.
 
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