Possible bad tune

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Old 06-03-2015, 11:14 PM
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Originally Posted by codyvette
Probably is directly related. It sounds as though your problem will end up being a bad ground or a shorted 5v reference. It could be anywhere. Good luck and keep us posted.
Well, now that I think about it, I did have an issue awhile back with the wires rubbing under the glovebox. However, that was only affecting my interior electronics, e.g. key remote not locking the doors, stereo (aftermarket) not working, etc. It's certainly possible that other wires are rubbing now. I'll take a look tomorrow at this poor GM design.

Thanks for all the input so far, guys.
Old 06-03-2015, 11:23 PM
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Sorry I have nothing to contribute to the thread, but Shackleford I haven't seen you post in years (at least not in the Texas Section)....You still got the same avatar from way back when. Good luck with your issue
Old 06-03-2015, 11:31 PM
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Originally Posted by Charlie Hustle
Sorry I have nothing to contribute to the thread, but Shackleford I haven't seen you post in years (at least not in the Texas Section)....You still got the same avatar from way back when. Good luck with your issue
Haha. No problem. You can always count on me and Daler Mehndi. LOL. I think that I'm a 10-year member by now, but I'll have to check. Thanks. I've always gotten good advice on here, so I'm sure that I'll get it figured out.
Old 06-04-2015, 07:18 PM
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It probably is the coolant temp sensor on the head
Old 06-04-2015, 11:50 PM
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Originally Posted by chrysler kid
It probably is the coolant temp sensor on the head
The trouble code is still in the system, but the temperature gauge was nominal.

Damn. Might have to drain the coolant, but it's a cheap part.

Last edited by Shackleford; 06-04-2015 at 11:56 PM.
Old 06-06-2015, 12:41 AM
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Tomorrow, I'm going to check the ECT sensor connector. What voltage should I expect? Also, I saw something online about a secret menu on the display to see the current ECT sensor reading - -40 if unplugged and 419 if there's a short or whatever.
Old 06-08-2015, 05:42 PM
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Is the battery hold-down bolted in properly?
Old 06-14-2015, 11:51 PM
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Originally Posted by Dirty 30
Is the battery hold-down bolted in properly?
Well, I replaced the ECT sensor but that didn't fix it. I'll check the battery hold-down tomorrow and look for anything that's loose.
Old 06-21-2015, 11:49 AM
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The battery is secure. I checked the two grounds near the battery, and their static reading was 12.64 V. I forgot to do a dynamic test. I read the resistance on the ECT sensor connector and it was 4.27 kilo-Ohms.
Old 06-21-2015, 05:25 PM
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Did you check all your ground connections and make sure they're tight?
Old 06-21-2015, 05:29 PM
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Originally Posted by audacious nick
Did you check all your ground connections and make sure they're tight?
No, I should've put a ratchet on them to make sure. How many ground connections are there? I found two near the battery.
Old 06-21-2015, 05:56 PM
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Originally Posted by Shackleford
No, I should've put a ratchet on them to make sure. How many ground connections are there? I found two near the battery.
Can't remember, but there are some on the front and the back of the engine.
Old 06-22-2015, 09:24 AM
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Originally Posted by Shackleford
No, I should've put a ratchet on them to make sure. How many ground connections are there? I found two near the battery.
Originally Posted by audacious nick
Can't remember, but there are some on the front and the back of the engine.
id check the back of both heads, down by the starter, on the block on the driver side and right above the battery.

to be sure, id do this. start at the battery and follow all wires to their destination. then do the same for the wiring harnesses coming from the PCM.
Old 06-22-2015, 01:33 PM
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Did you check the BCM wires behind the glovebox? The harness rubs against the metal and can wear through, causing electrical issues.
Old 06-22-2015, 05:39 PM
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Originally Posted by audacious nick
Did you check the BCM wires behind the glovebox? The harness rubs against the metal and can wear through, causing electrical issues.
Yes, I actually had that problem last year, but it caused problems with the doors not locking, cabin lights, etc. I checked the buffer that I put between the metal harness and wires and it's still in place. I didn't notice anything else.
Old 06-27-2015, 07:23 PM
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Yesterday morning on the way to work, the car died, and it threw the ECT code, so I dropped it off at a shop. Today, the guy said that they didn't find any problems in their diagnostic test. I mentioned that maybe it's a bad BCM, but he said that it would instead be an ECM problem. As for dying, he said that he noticed there was a bit of slack around where the MAF and throttle body are attached and that maybe the inflow of the extra air is causing it to die. I assume that he means in conjunction with whatever is first causing the car to act up.
Old 06-28-2015, 09:11 AM
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Originally Posted by Shackleford
Yesterday morning on the way to work, the car died, and it threw the ECT code, so I dropped it off at a shop. Today, the guy said that they didn't find any problems in their diagnostic test. I mentioned that maybe it's a bad BCM, but he said that it would instead be an ECM problem. As for dying, he said that he noticed there was a bit of slack around where the MAF and throttle body are attached and that maybe the inflow of the extra air is causing it to die. I assume that he means in conjunction with whatever is first causing the car to act up.
When it died did it still want to crank over but not start?

If that is the case it may be the crank sensor going bad Or your fuel pump

Just to be sure the car is full on coolant correct?

I have a bad ground on the back of the block and it causes my needles to jump around when I start the car and occasionally resets the trip odometer
Old 06-28-2015, 09:42 AM
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Originally Posted by chrysler kid
When it died did it still want to crank over but not start?

If that is the case it may be the crank sensor going bad Or your fuel pump

Just to be sure the car is full on coolant correct?

I have a bad ground on the back of the block and it causes my needles to jump around when I start the car and occasionally resets the trip odometer
Yes, it seems like I have to hit the accelerator to get it to start, and yesterday it stuttered and lunged after it restarted. When it does die, it happens when I'm stopped and the RPMs are low. If I can give it some gas when it feels like it might die, it doesn't.

A bad fuel pump didn't even cross my mind. A pressure check should be a quick and definitive indicator if it's bad.

Well, I haven't actually popped the radiator open recently, but when I did change the ECT sensor, coolant did leak out from the block.

The shop guy was adamant that he would have seen a bad ground/reference in his diagnostic test.
Old 06-28-2015, 11:27 AM
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Originally Posted by Shackleford
Yes, it seems like I have to hit the accelerator to get it to start, and yesterday it stuttered and lunged after it restarted. When it does die, it happens when I'm stopped and the RPMs are low. If I can give it some gas when it feels like it might die, it doesn't.

A bad fuel pump didn't even cross my mind. A pressure check should be a quick and definitive indicator if it's bad.

Well, I haven't actually popped the radiator open recently, but when I did change the ECT sensor, coolant did leak out from the block.

The shop guy was adamant that he would have seen a bad ground/reference in his diagnostic test.
You might just want to Un plug the iat sensor and MAF sensor to see if it runs better. If you have a k&n filer you could have oiled up the mass air and iat sensor so they are giving incorrect readings when compared to the coolant temperature sensor, and you can check the wire loom going to those two sensors to see if they may have gotten damaged somehow

When my IAT was bad the car would misfire like hell at anything above idle because it read temp as -136 degrees.

When my coolant temp tensor broke the car would go into limp mode and the fan would stay running for a minute or two after I turned off the car.

When my fuel pump went bad the car would barely rev itself above 3500 and struggle to make any power

And yes this all happened to the green firebird I use to own. along with a starter arching on midlength headers, window motors going out, headlight motors and a transmission. I was very close to letting the car live up to its name
Old 06-28-2015, 12:00 PM
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Originally Posted by chrysler kid
You might just want to Un plug the iat sensor and MAF sensor to see if it runs better. If you have a k&n filer you could have oiled up the mass air and iat sensor so they are giving incorrect readings when compared to the coolant temperature sensor, and you can check the wire loom going to those two sensors to see if they may have gotten damaged somehow

When my IAT was bad the car would misfire like hell at anything above idle because it read temp as -136 degrees.

When my coolant temp tensor broke the car would go into limp mode and the fan would stay running for a minute or two after I turned off the car.

When my fuel pump went bad the car would barely rev itself above 3500 and struggle to make any power

And yes this all happened to the green firebird I use to own. along with a starter arching on midlength headers, window motors going out, headlight motors and a transmission. I was very close to letting the car live up to its name
Well, the problem is that the car runs perfectly outside of the instances in which it hiccups. Usually, the car will just stutter/choke for a second and then idle up a bit, the TRAC OFF message always turns on, and the AC will turn off and then on. On the more unfortunate times, the AC compressor will not turn back on, but the fan will still blow.

Yeah, I had a load of problems with '95 Z28 and the terrible Optispark.

Oh, can I check for continuity at the IAT and MAF connector? How many ohms should I see?

Last edited by Shackleford; 06-28-2015 at 12:09 PM.


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