Screwy EGT Gauge readings..... help!

[Scollins]

I installed an Isspro EGT (Pre turbo) earlier this week, and it seemed to function correctly for a few days. I would get into the throttle, the EGT would climb. Get into the throttle hard, and the EGT would climb quickly.

However, I have noticed the following behavior over the last 2 days: When I get into the throttle, and the boost gets around 6 PSI, the EGT needle plummets to about 100 degrees!!!??? What the heck? It stays there through about 12 PSI then starts climbing again. If I get the boost up to 10 PSI, then lift off the throttle quickly, the EGT needle drops quickly, and then needle climbs rapidly to 600 degrees or so. What the heck is wrong with this thing, as I doubt this is normal operation.

I was very careful to hook up the wires to the appropriate terminal on the back of the gauge, so I don't I have it hooked up backwards. The wire from the EGT to the gauge does run along a wire loom for awhile. Could electronic interference cause this type of needle movement? Do I have a defective gauge? Thermocouple? HELP!

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Scott Collins
'98 Ram 2500 4x4 12 Valve Cummins. Slightly BOMBed! #ad

Renton, WA

[This message has been edited by Scollins (edited 02-02-2001). ]

 

[Jeff H]

I've got Isspro egt gauge too. Every time I drive it reads differently. Same rought too. Some days it reads around 450 to 500 on flat road. Other days it reads 600 to 700. Usually same speed. My only geuss is when it gets down to 0 degrees air temp. Egt seams to run at or around 600 wich is higher than my normal. When the temps are around 40 degrees outside. The egt seams to run under 600 degrees.

 

[WeirCummin]

Scott
Sounds just like the problem I had with my isspro EGT gauge. The thermacouple has a very low current milli-amp signal. it doesn't take much to interrupt the amperage from the t-couple to the gauge. I highly dout you are getting interference from any electrical current in the truck as the wiring to your gauge is shielded. more than likely there is a loose connection either at the gauge head or the connection to the t-couple. I would go back and check the connection and also check where the wires are crimped to the ring terminals. did you double nut the ring terminals on the gauge ?

 

[Scollins]

Thanks for the tips guys. I went back and retightened all of the connections. Also, I forgot to put the protective covers around the connections at the thermocouple. After doing these things, the gauge seems to be reading correctly again. At least the EGT needle goes up when I romp on the throttle. I'll keep an eye on it, and snug up the connections again in a few days. Boy, these Cummins sure do vibrate! #ad



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Scott Collins
'98 Ram 2500 4x4 12 Valve Cummins. Slightly BOMBed! #ad

Renton, WA

[This message has been edited by Scollins (edited 02-04-2001). ]

 

[paccool]

Now this is more than just a coincedence!!

I have ISSPRO gauge also (have had for about 1-1/2 years)and I have had to redo the connections at the gauge twice and need to do it again. Was doing the same thing you are describing. Mine sit on the dash, which really vibrates on the crappy roads we have here in northern Cal. and I think thats what is screwing up the connections. When it acts up, I can "tap" the gauge and it will start working again.

I'm going to move the gauges to a pillar mount and see if that cures the problem. (got to get the injector pump fixed first!)

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Stan
93 2WD extended cab, Banks Power Pack, K&N Air Filter, PW Injectors,Auto w/4. 10 rear with limited slip, US Gear Exhaust Brake, 31/2" Exhaust, 5K air bags, Boost/Pyro/Tach Gauges, Green/Silver, new 40-20-40 bucket seats, 149K

[This message has been edited by paccool (edited 02-04-2001). ]

 

[AlK]

Jeff, in addition to the cooler wheather another possible reason for the variation in the egt readings could be the wind condition. On the highway I usually activate the cruise control. The boost will go up when it is windy and in order to maintain the preset speed more fuel is needed and hence the higher EGT.
Cheers,
Al

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92-LE,4x4,5spd,3. 54,Borgeson steering shaft, Tach,Isspro Pyro & Boost, 16cm2, PW injectors