Normal operating temp for 4L80E in a plow truck?

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stutaeng

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Here's an article on how to check the TPS:https://easyautodiagnostics.com/gm/4.3L-5.0L-5.7L/tp-sensor-tests-1

I checked mine on that other thread I posted, and even swapped it with another known good one (from another engine I have,) as well as the IAC. Both were fine and didn't see any change on mine.

In my experience, a malfunction of most sensors on these engines will throw a CEL. The ECU is programmed such that it will know if voltages are too low or too high or voltage is not even present, missing 5V reference, etc.
 

thegawd

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except for the tps, I dont know what reference voltages it provides as I didnt test it that way, obd1 needs to be tested this way with a miltimeter. on a obd2 scanner it reads 0% to 100%. so missing data (a mechanically failed section) is read as 0% and reports it as the throttle is closed. so the circuit is functioning correctly it's just wrong data. this would be felt as a stumble, like in my case I had a stumble at 95km/h. it showed up on the scanner as a 0% on the graph.

Al
 

Pinger

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except for the tps, I dont know what reference voltages it provides as I didnt test it that way, obd1 needs to be tested this way with a miltimeter. on a obd2 scanner it reads 0% to 100%. so missing data (a mechanically failed section) is read as 0% and reports it as the throttle is closed. so the circuit is functioning correctly it's just wrong data. this would be felt as a stumble, like in my case I had a stumble at 95km/h. it showed up on the scanner as a 0% on the graph.

Al

I see my TPS output via my LPG software on a laptop. On a 0-5V sensor, typically they will show around 0.6V at idle and 4.6 - 5.0V at WOT.
They can have a bad sector though and lose contact between those extremities.
 

DerekTheGreat

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...I stopped by the trans shop today and talked to them. He said the reverse band is probably starting to go. He said reverse is all mechanical so it's just probably that. He told me it would be around $2500 for a rebuild to beef it up like it belongs in a plow truck...


Seeing as you're in S.E. Michigan like me, you might want to try out Accurate Transmissions out of Belleville. Worth the drive. Address is: 41251 E Huron River Dr, Belleville, MI 48111.

I hate automatics, but my wife had an '89 Town Car with a dead AOD. They rebuilt it to stock specs and you'd never know it was rebuilt. I think we put 15 or 20k on it before we sold it. Two years later, it was still going strong, last I heard.
I was referred to them by a long time friend who has been taking transmissions to them for decades. He's had them build transmissions for race applications, plow and regular daily driver status. Just tell them what you're doing or would like and they'll take care of it.
 

upper_tanker

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Sorry the taking so long to reply. I will check out the TPS and test it. I don't think my dad has ever replaced it, so it may be time. I'd poop my pants if that was the issue. My life doesn't really work like that usually.

Also, the truck does have the infamous injector issue. The Five-O injectors were next on my list. The truck has had the slight misfire and extended hot start issue since he bought it probably 7 years ago. It's not enough to affect the drivability, just starting it up when it's hot and when it's in park idling.

I think I said this earlier, but my entire plan was to spend all/most of the money I make plowing this year getting the truck up to par so hopefully the next few years will only be minor maintenance issues.
 

udidwht

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With respect to the 4L80E another common issue...

An internally cracked wiring harness connector. Do you see any trans fluid where the trans connector connects to the transmission harness? You shouldn't. Leaking fluid into the connector will short out the circuit/s causing shift/ing issues with the trans.

If you do. You'll need to purchase a wire harness then drop the pan and replace it. While you have the pan down I'd replace both the shift solenoids (A & B) as well.
 

udidwht

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Sorry the taking so long to reply. I will check out the TPS and test it. I don't think my dad has ever replaced it, so it may be time. I'd poop my pants if that was the issue. My life doesn't really work like that usually.

Also, the truck does have the infamous injector issue. The Five-O injectors were next on my list. The truck has had the slight misfire and extended hot start issue since he bought it probably 7 years ago. It's not enough to affect the drivability, just starting it up when it's hot and when it's in park idling.

I think I said this earlier, but my entire plan was to spend all/most of the money I make plowing this year getting the truck up to par so hopefully the next few years will only be minor maintenance issues.

The misfire can be related to....

1. Burnt spark plug wire/s

2. Fouled plug/s

3. CTS (Cooling temp sensor)

4. O2 sensor

5. MAP sensor

I'd replace at min the cooling temp sensor and wires/plugs.
 

upper_tanker

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The misfire can be related to....

1. Burnt spark plug wire/s

2. Fouled plug/s

3. CTS (Cooling temp sensor)

4. O2 sensor

5. MAP sensor

I'd replace at min the cooling temp sensor and wires/plugs.

I was just assuming that it was the famous injector issue because it has very long, hard starts when the engine is fully warmed up. Also, it only has a VERY slight misfire at idle, but runs perfectly when driving it. I'm also going to do the FPR when I do this as well.

I will definitely do the plugs/wires/map/and CTS, as I'm not sure if those have ever been done.
 
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