'86 GLHS And Code 22, Alternator?

[Marcus86GLHS]

not having a lot of luck with the car this year. need some help from the experts.

On the way to the car show last nite the power loss lamp came on, I pulled into the pumps, shut it off, got some 105 unleaded, and the car fired right back up, no power loss lite. car ran fine.

3 more miles down the road the power loss lite came back on. i parked in the show field. about 1.5 hrs later when i went to leave the car would not start. it turned over fine but would not start. i pulled the battery cable to clear the codes and i finally got it started after several minutes of turning over. its never done that before.

Made it home and checked codes: 12 and 22. (12 was expected of course).

Questions:
1. How can I test the coolant temp sensor? I dont have a diagnostic tool just a multi-meter.

2. If the coolant temp sensor is bad, can that cause the problem with difficult starting?

3. Could a bad/weak alternator cause the Code 22?

4. Whats the easiest way to test the charging system?


I ask cause I have a brand new alternator (all connections are tight and clean), this is the first time I drove the car with it, and I noted the voltmeter gage seemed to be just a tad lower than before, at idle with the parking lights on the needle went just above the red area a couple times but was in the normal range most of the time while driving.


Thanks for any advise you could offer.

[jonnyb]

Mark - the alternator shouldn't have anything to do with a code 22. However, once you get the code 22 and the power loss lamp is turned on, the ecu also turns the fan on until the code 22 goes away, so that fan always being on could put a pretty good load on the alternator (especially driving at night with your lights on).

If the car was turning over fine, I wouldn't worry about the alternator.

The no start was most likely due to the ecu not knowing the temp of the coolant, which is a big part of the starting fuel routine. It was probably throwing way too much fuel in the engine for it to start (pretty common in a car with bigger injectors and a bad coolant temp sensor).

Feel free to give me a call if you want.

Jon

[Marcus86GLHS]

thanks Jonny, will do.

the other thing i wanted to mention is that prior to this code 22 popping up last nite, i had started the car and allowed it to fully warm up at idle at least 10 times in the past week (after replacing the water pump for the 3rd time). The car always started fine, the cooling fan cycled on and off fine multiple times, and i never got a power loss light of fault code. keep in mind this was with the car sitting at idle, not driven. but it did achieve maximum temperature many times w/o a problem or code.

if all that is functioning, how can this sensor be bad? maybe it's one of these intermitent electrical gremlins?

or, does vehicle speed effect coolant temp sensor monitoring by the logic module?


this morning i reset the code, the car started right up, warmed up, no power loss light and no code 22.

wtf.

[86Shelby]

You may have in intermittent bad connection or short in the circuit for the temp sensor.

[risen]

Questions:
1. How can I test the coolant temp sensor? I dont have a diagnostic tool just a multi-meter.

You can test it with a dvom. I don't have the ohm ratings at hand, but if you search around here I'm sure you can find the ratings. I know they're on the other site if you want to use google to search. You'll probably need to do some estimation based upon the current temperature outside to figure of what th proper ohm value should be.

2. If the coolant temp sensor is bad, can that cause the problem with difficult starting

It could if the sensor was telling the ecu that the engine was at 180 degrees instead of 60. It probably wouldn't use the proper cold fuel table if the sensor was way off.

[turbovanman²]

thanks Jonny, will do.

the other thing i wanted to mention is that prior to this code 22 popping up last nite, i had started the car and allowed it to fully warm up at idle at least 10 times in the past week (after replacing the water pump for the 3rd time). The car always started fine, the cooling fan cycled on and off fine multiple times, and i never got a power loss light of fault code. keep in mind this was with the car sitting at idle, not driven. but it did achieve maximum temperature many times w/o a problem or code.

if all that is functioning, how can this sensor be bad? maybe it's one of these intermitent electrical gremlins?

or, does vehicle speed effect coolant temp sensor monitoring by the logic module?


this morning i reset the code, the car started right up, warmed up, no power loss light and no code 22.

wtf.

Shitt happens, its like your tv is working fine then one day, you go to turn it on and nothing, same with computers etc. Electrical components seldom give warning of failure.

[Turbozcs2003]

Original Coolant temp sensor???

I would swap in a new mopar sensor. AS Cliffy says, verify with known good parts.

[Marcus86GLHS]

Thanks.

Problem appears to have been a bad sensor connection, all i did was disconnect, put a dab of dieletric grease on the connector, and hook it back up. Took it for a test drive and all is working fine.

I guess what was freaky about this code 22 was the timing of it: i had been effing with these stupid bad water pumps for a long time and sure enough once i finally get a good waterpump on the car i get a bad coolant temp sensor code.....but, it appears to be a pure coincidence. It's easy to see why some folks hate these cars.

[Turbozcs2003]

Thanks.

Problem appears to have been a bad sensor connection, all i did was disconnect, put a dab of dieletric grease on the connector, and hook it back up. Took it for a test drive and all is working fine.

I guess what was freaky about this code 22 was the timing of it: i had been effing with these stupid bad water pumps for a long time and sure enough once i finally get a good waterpump on the car i get a bad coolant temp sensor code.....but, it appears to be a pure coincidence. It's easy to see why some folks hate these cars.

What pump did you buy and where did you get it?? This is the early 2.2 WP.

[4 l-bodies]

Mark,
When I start having intermittent, illogical, random issues like this I have learned to suspect the pin connectors at the logic module. I lost a piston in my low mileage 85 GLHT because the detonation sensor would work when it felt like it. Numerous random failures over the years have stranded me a few times as well. Many times the logic module bag doesn't get reinstalled and corrosion starts in the red and blue connectors. I wonder what % of logic module cars still have a sealed bag around their logic module? Pretty low % I'd bet. Also after changing out the logic module repeatedly over the last 25 years, the pins just get weak. I chased intermittent issues more than once with these cars and most of the time it was a bad connection at the LM.
Being that the cars are stiffly sprung and with ultra stiff Koni shock valving and low profile tires just adds to the pounding that every part of the car sees and compounds the problem.
Todd

[Marcus86GLHS]

so true Todd...last year i was getting a code for a failed TPS and after numerous tests and parts swaps I finally diagnosed it correctly as a bad pin at the logic module, again a dab of dielectric grease fixed that one. the bag over my LM is long gone but the car is kept very dry year round not even washed.

i'm not 100% confident this code 22 is fixed, but i'm driving it to MA over the 4th holiday (right after sdac) for a huge car show so that is when it is likely to fail again. it has to. God wont let me have fun with this car in 2010.

TURBOZCS: i made a thread on TM.com about my waterpump issues in this same area of the site if you want to check it out.

[black86glhs]

Mark I had several baad LM connections when I first got my S. I recommend you also tweak the terminal for better contact. The dielectric is good, but proper mechanic connection and dielectric is better.