Engine Problem
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 17
Likes: 0
From: Tax State USA NY
To all you guys that kept questioning the engine temp: It looks like we found the problem last night with the scanner. My engine temp is showing @38-40* lower than what the scanner is seeing. Also the MAS temp appears to be off as well. I will change out the temp sensor and do a cleaning on the MAS and see if that works, if not I 'll replace it as well. I'll try to find the parts tonight and install if time permits and update everyone. Thanks again for all the help!
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
To all you guys that kept questioning the engine temp: It looks like we found the problem last night with the scanner. My engine temp is showing @38-40* lower than what the scanner is seeing. Also the MAS temp appears to be off as well. I will change out the temp sensor and do a cleaning on the MAS and see if that works, if not I 'll replace it as well. I'll try to find the parts tonight and install if time permits and update everyone. Thanks again for all the help!
I am always suspicious when guys say their c4 is "normally" cool, but has running issues. I also notice that when CTS is mentioned as a potential cause, many people ignore it. I guess the assumption is that O2 sensors are in control. If you follow the forum you will see many issues with CTS as a root cause, so it pays to question everything.
joe
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 17
Likes: 0
From: Tax State USA NY
FSM, 6e3 c1 3, says "the CTS affects most systems the ECM controls." If it is functional but out of internal calibration it won't send a code.
I am always suspicious when guys say their c4 is "normally" cool, but has running issues. I also notice that when CTS is mentioned as a potential cause, many people ignore it. I guess the assumption is that O2 sensors are in control. If you follow the forum you will see many issues with CTS as a root cause, so it pays to question everything.
joe
I am always suspicious when guys say their c4 is "normally" cool, but has running issues. I also notice that when CTS is mentioned as a potential cause, many people ignore it. I guess the assumption is that O2 sensors are in control. If you follow the forum you will see many issues with CTS as a root cause, so it pays to question everything.
joe
I have only been a C-4 owner for a month now, and I have recieved more help and expertise advice here than from anywhere else. My biggest problem is I know enought to get me in deep doo doo most of the time. So to all thats helped thanks again and maybe someday/somehow I can repay you all. Will update with results from new CTS.
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
best see that the sensor cures the problem before celebrating!
others noticed the temp, too. these threads are crap shoots, you know? no one knows as much about the problem as the OP, so it's a guessing game. I might have been lucky.
when you remove the yel and blk 2 wire plug, I think you can check the terminals for 5v. the harness is part of the circuit. most likely the sensor.
saludos, joe
*** the fsm does not mention that the sensors fail without setting codes. I got that from a thread a week ago, from member SunCr. seems to be common.
others noticed the temp, too. these threads are crap shoots, you know? no one knows as much about the problem as the OP, so it's a guessing game. I might have been lucky.
when you remove the yel and blk 2 wire plug, I think you can check the terminals for 5v. the harness is part of the circuit. most likely the sensor.
saludos, joe
*** the fsm does not mention that the sensors fail without setting codes. I got that from a thread a week ago, from member SunCr. seems to be common.
Last edited by joe paco; Sep 25, 2011 at 05:59 PM. Reason: forgot***
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 17
Likes: 0
From: Tax State USA NY
best see that the sensor cures the problem before celebrating!
others noticed the temp, too. these threads are crap shoots, you know? no one knows as much about the problem as the OP, so it's a guessing game. I might have been lucky.
when you remove the yel and blk 2 wire plug, I think you can check the terminals for 5v. the harness is part of the circuit. most likely the sensor.
saludos, joe
*** the fsm does not mention that the sensors fail without setting codes. I got that from a thread a week ago, from member SunCr. seems to be common.
others noticed the temp, too. these threads are crap shoots, you know? no one knows as much about the problem as the OP, so it's a guessing game. I might have been lucky.
when you remove the yel and blk 2 wire plug, I think you can check the terminals for 5v. the harness is part of the circuit. most likely the sensor.
saludos, joe
*** the fsm does not mention that the sensors fail without setting codes. I got that from a thread a week ago, from member SunCr. seems to be common.
? What sensor is on the driver side head between the intake and manifold? It looks like the connector is cracked! Did't have time to investigate it yet.
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
Joe, no celebration yet! I changed out the sensor, with a cheap one. Didn't have the Delco replacement! Now the temp is running @20* lower than it was before. (135-145). I did not check the voltage on the wiring yet. Just wondering if the ECM is going south, or a problem with the cheap CTS.
? What sensor is on the driver side head between the intake and manifold? It looks like the connector is cracked! Did't have time to investigate it yet.
? What sensor is on the driver side head between the intake and manifold? It looks like the connector is cracked! Did't have time to investigate it yet.
the knock sensor is in the BLOCK, as you prob knew, but may be in the front location. my 91 has a sensor "gage overheat" but I am not familiar with it.
, not sure how ecm uses the actual gage, or if it does. got confused in previous post thinking CTS sent a signal to gage like oil temp sensor but it does not.
need to review my fsm to get my thoughts collected!
joe
have had a problem for some time with this page, often deleting part of the page, esp when inserting
or other.*** now that it is too late, I realize that the sensor for the digital temp gage AND the red overheat light are controlled by that sensor I mentioned -probably the one you are seeing. The one you unplug accidentally when changing 6-8 plugs! I mentioned in a thread some time ago that the temp gage and CTS were not the same, but had forgotten why.
good thing you are not celebrating too heavily! the low temps are a clue, but not the solution, looks like.
Last edited by joe paco; Sep 26, 2011 at 10:00 AM. Reason: correction/clarity***
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The ECM does not use the CTS that shows the temperature on the dash. It has it's own CTS under the throttle body.
Are you sure you have all the spark plug wires in the right holes in the distributor cap?
Are you sure you have all the spark plug wires in the right holes in the distributor cap?
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 17
Likes: 0
From: Tax State USA NY
I will try to find the right parts (CTS) and install next week also.
Leaving town for the wknd for a fishing tourney. Maybe I can find some luck fishing!
Thanks again to all for the help. I will not give up, relentless!
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Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 17
Likes: 0
From: Tax State USA NY
Sorry guys for the long wait. I replaced the CTS with the A/C Delco brand. No change. Still reading low. @140*. When driving it around after the changout, I got the service Engine light again. Stopped and checked codes...NONE. Just the #12 again. Cleared code, fired it up and got almost home light comes on again. Checked again...NONE. What could be causing the light to come on and no codes displayed!! Still have not checked the wiring other than a quick peek. Planning on pulling dist plugs one at a time to see if I can find a problem with a cylinder. Thanks guys for the help. AND, no luck fishing either!
Racer
Joined: Aug 2011
Posts: 494
Likes: 138
From: Chesapeake, VA
Sorry guys for the long wait. I replaced the CTS with the A/C Delco brand. No change. Still reading low. @140*. When driving it around after the changout, I got the service Engine light again. Stopped and checked codes...NONE. Just the #12 again. Cleared code, fired it up and got almost home light comes on again. Checked again...NONE. What could be causing the light to come on and no codes displayed!! Still have not checked the wiring other than a quick peek. Planning on pulling dist plugs one at a time to see if I can find a problem with a cylinder. Thanks guys for the help. AND, no luck fishing either!
Bad plug wire
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 17
Likes: 0
From: Tax State USA NY
Well guys, finally got the old girl to throw a code. #33. MAF is in question now. I have cleaned this sucker a couple of times with the MAF cleaner sold in the parts store. I'm sure one of you guys can give me some advice on the MAF. Priced out from @150-250 bucks, depending on name brand etc. Should I replace or is this just throwing money out the window? Looks like there could be several things associated with this code!
REDTREX - I have replaced the 02 sensor and the plug wires. O2 sensor went in with the new exhaust replaced a month or so ago. Could have a bad plug wire. I have never seen a new one go bad, but possible.
When the code came in the car car "stumbled" for a second on take off. Almost like it quit for a moment and then picked back up. Maybe this info will help in diagnosis?
I would like to get this thing running correctly before a long winter storage!!!
REDTREX - I have replaced the 02 sensor and the plug wires. O2 sensor went in with the new exhaust replaced a month or so ago. Could have a bad plug wire. I have never seen a new one go bad, but possible.
When the code came in the car car "stumbled" for a second on take off. Almost like it quit for a moment and then picked back up. Maybe this info will help in diagnosis?
I would like to get this thing running correctly before a long winter storage!!!