BACKGROUND
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According to Dave's roommate James, Dave was a recovering ricer himself... anyways, long story short: I spent the weekend just tearing (& replacing) his interior & tracking his wires/lines in the process. In the music industry, we call the garbled mess that was his center console 'spaghetti' ... needless to say, I did a LOT of cutting.

The reason why I did all the cutting is cuz Dave wired his car for neons & also had a sub run to the back (& crossover). Well, before I bought the car, he simply cut out all his toys (neons, amp, etc)... so there was a TON of unterminated wires, and it was a HUGE mess! It's amazing to me that it even worked in the first place as many splices & rerouting of power that he did. Come to think of it, I wonder if it's not the reason why Dave said his EGT gauge was bad (Dave thought it was the wiring, but eventually chucked the gauge instead).

RESULT
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Anywho, the car idles perfectly between 800-900 rpms just as it should. Also, the A/F has leaned out greatly (a good thing). No longer is the A/F reading 100% rich, rather it's Stoich (1/3 towards the rich side).

Unfortunately, yes there's a down side, the radio no longer works!!!

Help! Pleaz read post here:
http://forums.2gnt.com/dcboard.php?az=show_topic&forum=10&topic_id=11536&mode=full

Thanx,
- J

I hooked up my new EGT gauge to the existing probe (in DP) using existing wire just to see if I could get a quick read. w/ the engine coolant atleast warmed up to normal in ~2minutes or so, I only got a reading of 100' w/ the car sitting still in parking space (no matter if @ idle or rev'ing engine). Bearing in mind the gaping exhaust manifold leak, is this low temp normal given these conditions? I would assume not...

Was wanting 2 replace his probe, how brittle is this? Can I simply unscrew & screw in the new probe?



If it is brittle, would you instead recommend leaving it in there as a plug & drilling a hole on the #4 runner?

Much appreciated!
- J

Originally posted by J
I hooked up my new EGT gauge to the existing probe (in DP) using existing wire just to see if I could get a quick read. w/ the engine coolant atleast warmed up to normal in ~2minutes or so, I only got a reading of 100' w/ the car sitting still in parking space (no matter if @ idle or rev'ing engine). Bearing in mind the gaping exhaust manifold leak, is this low temp normal given these conditions? I would assume not... Was wanting 2 replace his probe, how brittle is this? Can I simply unscrew & screw in the new probe? If it is brittle, would you instead recommend leaving it in there as a plug & drilling a hole on the #4 runner? Much appreciated! - J

yes you can screw in a new probe. It's not brittle.

Temp wise, there is definitely something wrong with the temp reading... it's obviously either the probe, wiring, ground, or the gauge itself. Just trace and check how the wiring is, and the ground. Then trace to the probe and gauge if the first two don't work. At idle, the temp should be about 700 I believe.

The probe itself is not brittle, the fitting screwwed into the DP may be a problem. If any threads are exposed inside the DP then you might have a hard time getting it out without ruining the threads on the fitting. Mine stripped the threads on the fitting when I removed it. I might have a spare probe liek the one you have since I changed to a TRE probe. I will look, if i do you can have it for the price of 15.00 shipped. I am not sure i saved it or not since I can no longer use it.

Terry

Shouldn't the EGT probe be in the number 4 exhaust port rather then in the downpipe? That's where mine is and it gets perfect readings. I'm not sure what kinda probe your using but I have the factory autometer probe if you want it for testing.

technically on the 420a its the number 1 plug. Injector number 1 is farthest from the fuel feed and has a better chance for being lean if there is a fuel source issue caused by lack of volume. In the 4g63 it should be in #4 since there rail is the reverse from ours.
Reading in the DP is ok as long as you account for a 200 degree F drop due to the distance from the exhaust port. The EGT will also be a average from all 4 cylinders. So, cyl 4 can be running pig rich and Cyl 1 can be lean as hell but your EGT will look great.

SOoooooooooooooooooo, I've got 1x no prob go ahead & 1x the threads may strip out. HMmmmmmmmmm, so basically I've gotta 50/50 chance of having a nice easy time for replacing the probe. Ugh.

As for the temp... I wouldn't think it's the probe (only 20k miles), definately not the gauge, but the wiring on the other hand... let's just say I've been having a painfully dismal time of sorting out the mess. The wire from the probe itself is already split in two places where Dave evidently tried to determine if the wiring was bad. As for the grounding, well... let's just say it was the reason why the car wasn't idling properly.

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Thanx Star, I appreciate it, but I've still got the probe that came w/ the gauge.

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Yep, U're right in that the runner closest to the battery will provide the highest temp which is why most prefer it there. I believe Dave simply put it in the DP cuz that's where HRC recommends & he followed it to the letter (which is good).

I don't remember the reasons why some say the DP other than it's after the turbo, so you don't have to worry about the probe breaking up & you breaking down... which I've read is unlikely. Most of my knowledge is from reading & searching on here for so long & not of actual experience, so take it as you will.

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I guess I'll just see how 'loose' the probe is, I don't want to strong arm it & risk being in a not-so-pleasant situation. If it's tight, I suppose I could try some WD40, but I'll prob just run new wire & hope that's it. If not, I'll prob leave it as a plug & put new probe in runner.

50/50 pretty much sum it up?
- J

If their is any cuts on the probe wires (ie someone cutting it), then it will change the readings. According to autometer, cutting the probe wires ruins its resistence of something to that effect. Point is, it is not meant to be cut in anyway.

Just fucking yank it out. Too much thinking. Just do. 50/50? just do it.
blah.


Gil??

The runner closest to the battery is not runner Number 1....its number 4 and will not give the highest reading. number 1 is always closest to your pullys.

Terry