EGT cooldown times for autos

[dpuckett]

I got a pyrometer and boost gauge at the little cookout in IN a few months ago, and finally got around to putting it into Mom's pickup. It is post turbo for now (dont have the little compression fitting to put it in the manifold- it came with a clamp on fitting for post turbo), and it takes FOREVER to cool down to 300deg. 285 is about the lowest it gets, even if it sits for 10 min. Is this normal? I've only ever put pyros in manual transmissioned trucks, and they normally get cool enough within 30 sec when empty. I've shut Mom's off after waiting 4 min, and it was still at 350!!! My pyro is in the manifold, has hotter injectors, and no intercooler, and it cools off a LOT faster than hers. I realize that it takes longer to cool off post turbo, but I was thinking this was a little extreme. She ran a double dose of Gumout diesel injector cleaner for 2 tanks, and she said it helped a little, but it still takes its time cooling off. Could it need new injector tips? Pump was redone about 40K ago, and sounds better than mine; injector tips checked out ok at the time. This was the shop (located not too far from here, and shall remain unnamed)that I will no longer patronize due to what I consider to be sub- par performance and quality of workmanship. Is it time for a set of Bosch 190s? Though she cringes at $400 for the set. I tell her a set of stockers is around $300, and they may or may not be balanced.



Daniel

 

[dan brooks]

For normal empty city driving, it normally takes about a minute for mine to hit 300* pre-turbo. I've never had it take more than about three minutes, even after pulling hills towing the Jeep.

 

[BushWakr - RIP]

I think I'd be suspicious of the thermocouple or the gauge here... .

It does seem to take a bit longer for a post turbo install to show cool down but that is due to the built up heat in the exhaust housing being pushed into the downpipe by the exhaust... at least that's my theory.

Still the type of mount (clamp-on) and the probe may be a bit off.



pb... . well guys??????



edit: by the way, I have found that any accessories left on will delay cool down too... . even the heater in my truck will hold up the cooldown process. .

 

[bgilbert]

I'm thinking its that heavy dense swamp air down there contributing to the longer cool down time. Don't know, give me a few weeks, I'll have boost and pyro-pre, installed in my early 91 auto stocker.

 

[JLEONARD]

Daniel,

I'd be suspicious of the accuracy of the gage (or thermocouple). It would be nice if you could get ahold of a ir temp gun and verify the reading before you go nuts (ok too late, I know).

Autos do take a little more time to cool down as they are always under a load , but what you are describing seems a bit excessive for a stocker.

Something doesn't make sense to me.

Jay

 

[EZGZ]

Daniel

I have a 91 with 16mm. I put a US gauge Pyro on mine post turbo.

Mine reads the same way you describe yours. The only way I see mine dip to 250 is coasting downhill.



Been that way for 8 years. Just use comon sense and see what norm is for your particular set up. Trying to get someone elses numbers will just cause you grief.

 

[dpuckett]

EZGZ-

This is WAYYYY off of what I have found ot be normal. I have had several set-ups, and never took this long to cool down. I may try my t-couple and leadwire- they are both ISSPROs, so it should work. Might even swap gauges for a while if I get feeling ambitious. Peak EGT is about 800, with 17psi boost.



Thanks, guys. And yes, ECJay, it is too late to avoid insanity. Another thing that makes me think the gauge isnt too far off is it hasnt had the pyro the last 120K, and it has been shut off fairly soon after parking, etc (stock set up, should be cool by then, right?), and the turbo has almost as much slack as the one from my 91- way more than the . 003" the book calls for.



-DP