Jump to content
Posted

Alright, so with what I'm runnin' on my truck, I noticed something particular. Running at highway speed, I approach a grade. I keep on the throttle and EGT will go up as it should. Except, the temp on the gauge goes from 600 or so, climbs to 800, stops. It struck me as a little weird that it would just stop like that. Especially considering the fact I was pretty much about 2/3 the way up the grade.I got into the throttle more to see if I could make it climb more, but at this point, I had the turbo spooled up and the load decreased into relation of the grade and speed I gained.I coulda swore I could get the egt's to shoot higher. They have before... :think:Just trying to make sure my gauge is not broke or something.

  • Replies 16
  • Views 2.4k
  • Created
  • Last Reply

Top Posters In This Topic

Featured Replies

yeah, something seems odd. you should be able to get the EGTs to climb north of 800*F. does it stop solid at 800?

MIne is acting in a similar manor. If I stand on it hard it will go up to about 800* and sit there until I back off, then it will jump up in the 1200* range very quickly. Some times it works fine and others not. It was reading crazy low temps the other day. I was thinking bad thermo couple, but I believe Hex change his out the other day.

I am going to have to check, but what I remember about mine is the wires from the thermo couple runs to the tuner and then to the gauge. All my paperwork on it is in NC.

  • Author

Right, I just replaced my thermocouple. I DO NOT have an amplifier for my gauge. It is a Dipricol.I'm wondering if I was lugging my engine and when it hit 800 thats when the engine caught up and the auto decided it was not worth downshifting but just let it accel.

My Isspro uses an amplifier box and a couple years ago it started reading low. A quick call to Isspro and they told me how to test it and the gauge to determine what the problem was.Thats not to say your gauge or thermocouple is bad though, unless you're very aware of normal gauge readings.

My Isspro uses an amplifier box and a couple years ago it started reading low. A quick call to Isspro and they told me how to test it and the gauge to determine what the problem was.

Thats not to say your gauge or thermocouple is bad though, unless you're very aware of normal gauge readings.

I am reasonably aware of my readings. I could not quote them to anyone. Mine is just runnin whacky right now. When I go to work in the morning it seems to work right. Later in the day I start getting the whacky readings.

- - - Updated - - -

Are both of you (OP and Dripley) using signal amplifiers for the gauges? If so that might be what's wrong.

Would a signal amplifier be present in a tuner? Dont forget I live in the world of elctronics neophytes.

dripley, You're anything but a beginner and I'm sure you are completely aware of your gauge readings. I've become so accustomed to watching my pillar that I forget to watch important things like MPH. :)And I'm not sure if there's amplifiers in tuners.

dripley, You're anything but a beginner and I'm sure you are completely aware of your gauge readings. I've become so accustomed to watching my pillar that I forget to watch important things like MPH. :) And I'm not sure if there's amplifiers in tuners.

Coming from you that is a compliment. I am aware enough to see any major differances in EGT's empty or loaded. To give you a detailed spread sheet of what they are would be difficult. The gauge readings I am seeing are beyond what I think the engine is really seeeing. I have to think it is an electronics proplem and not a physical problem with the engine. I can still flog this truck and get great performance, but in the same breath, not always no why.
  • Author

Alright, so I took a torch to the probe. I hit it for a little bit and it went over 800. Did not act funny or anything so, I suppose it is working just fine...I drove the truck after purging the fuel line to gauge to see how much better it would perform. I think that when my turbo really kicks in at higher boost, it just does not allow the egt's to rise more than 800.Dripley, you oughtta have someone watch your gauge as you hit it with the torch and see how it reacts.

As much as I commend you for thinking outside the box, what you did is not really telling you anymore than what you already know, and that being that the thermocouple is reading something. Accuracy is what you really want to know. Is what the gauge is showing you the right reading.

  • Author

As much as I commend you for thinking outside the box, what you did is not really telling you anymore than what you already know, and that being that the thermocouple is reading something. Accuracy is what you really want to know. Is what the gauge is showing you the right reading.

True. But, I atleast know it will go above 800. I'm gonna have to hook a battery up to the gauge. Dig up my other thread and compare numbers...

Is there an ohm test you can do to verify thermocouple accuracy?

  • Owner

I've done a bit of Google searches and turned up all kinds of documents and such but nothing exactly as for testing with a ohm meter really. One guy mentions that a lighted candle is roughly 800 degrees (Celsius I think) and should produce 3.2 mV from the terminals (open load).

  • Author

Is there an ohm test you can do to verify thermocouple accuracy?

You do not measure it in ohms. You measure it in voltage. Apply heat to the thermocouple, you will watch the DMM show an increase in voltage as it gets hotter. So, if I take a battery and hook the leads up to it, I can watch the gauge. Whatever the voltage is on the battery, will correspond to what the temp. would be on the gauge. The key though, is to know whether or not the gauge is displaying the right temp. for that amount of voltage. I wish I had a potentiometer... Wonder of radioshack has one...