It seems that my exhaust temps are to high. Stomp was over to the house today and we were looking at my truck to see if I was just being paranoid over my EGTs. I let the truck warm up and we took a ride. When I WOT it took off pretty good, there was no smoke, I ran it up to 70mph and I hit 1400 degrees. We did this a couple of times and it varied between 1300 and 1400 degrees. At idle, in drive, it is at aobut 600 degrees, it will cool down if I put it in Park. Just taking off easy, 1/4 throttle, It will reach between 1000 and 1150 degrees.

It is a 93 truck, 2wd. I have advanced the timing an 1/8 inch. My Pyro is pre turbo. I have a K&N filter, I have a magna flow muffler and it exits before the rear tire so there is no going over the rear axel. It is 3 inch though. The pump was rebuilt about a year ago by the same folks that did Stomps. I don't think they turned it up at all. I have a 16cm polished turbo. I get 19 lbs of boost at WOT. I don't think I am over fueling because there is no smoke when I WOT. Injectors are stock and original.

I am trying to get ready to pull a 6500 TT and it scares me to think of the temps that I will encounter. I keep reading about other peoples temps at pre turbo and pulling they don't see temps that I have empty.

Because there is no smoke, could it be that it is to lean?? (I know that with a gas engine, if it is lean, it will be hotter egts. Is it the same with a diesel???)

Does anyone have any suggestions, please.

Thanks in advance.

Larry


By the way, I took a ride in Stomps truck. That was fun, what a great ride
and thanks to Stomp for coming over.

 

I suggest a smaller turbine housing for more boost.

 

Did you install the pyro? Did you cut the wires so there would not be a bunch left over? Try to verify to operation of the pyro and thermocouple, before you get too serious.

 

I can mash it to over 70 and it usually won't go over 1100-1150 and the truck is pretty peppy.

If the pyro install is correct, it sounds to me like you have more full power adjustment than you think you do. I have 2 turns from my stock setting. If I go to 2 1/2 turns the temps start coming up quite a bit and it's still not blowing clouds of smoke.

How about getting the intake air flowing with the BHAF setup. Is that something your willing to do, or do you prefer to keep the factory setup?

I think at a year, your rebuilt pump warranty is prolly history. Time to pop some caps off and change some settings. I vote for 1/2 turn out on the full power screw for starts.

Then once you get your temps in check set the high idle for max travel. I think some adjustment on your high throttle and you can get 22-24 boost. I get 24 and I have the worst housing..the 21cm.

Just curious. How's the truck shift? Does it plain off at the top of each gear or does it keep power and shift?



Den

 

Also check thoroughly for boost leaks. I can't believe I forgot that.

Mudcat's suggestion is a good one, too. I don't have an auto, but 600 degrees at idle sounds kinda high to me. How cool will it get in neutral if you let it sit for a couple minutes? If it won't get down around 200 the pyro is wacky.

 

Im thinking double check pyro also. Try a lazer pyro on the exhaust manifold. If you know soomeone else thats close (that doesnt have twin turbo's) you can try to get a baseline.
-Jim-

 

mines an 89 non intercooled auto at idle mines at 300 in drive, i can see pretty high temps at wot, but its blowing a lot of smoke,,,do what the others said but might take a peek at the exhaust just make sure its not mashed bad some where.

 

I checked the exhaust and it isn't mashed anywhere.

At idle in park it will get to 300 degrees after a couple of minutes (2-3).

What is the best way of checking for leaks.??

The truck shifts pretty good and solid. A little slow into overdrive if I have the throttle mashed to the floor.

How does one check the pyro?? just get a new one?? or is there a better way


larry

 

Depending on what was done on the rebuild, I'd agree with the guys here....your idle temps are too high...in "D" with a low stall TC mine will run at roughly 250-275*F....if I slip it into "N" then it will climb up to about 300'ish*F.
Your boost numbers and your other temps really seem to suggest you have boost leaks somewere...
You have to pressure test the entire system. I think Stomp can help you with that. What is needed is a piece of heavy rubber tubing the diameter of the turbo air inlet.... that hose also needs a cap or plug on the opposite end with an air fitting and a cheap air gauge.

You pressurize the system to 20psi and, shut off the air supply....go looking/listening/hunting for leaks....remember that there will be a slow leakdown because the valves are not all closed at any time so you'll get some pressure drop...you should NOT get a rapid drop though.
The old soapy water in a bottle will help with the IC check since some leaks are too small to hear and you need to find them visually.

To check a pyro all you need is a thermal gun....most equipped shops have one...
Remember that if you change the probe you may also have to change the "box" that is attached to it for proper calibration. If the probe is "of the same make/range" then you "should" be ok to just swap it out.

Also the larger the turbo exhaust housing the lower the max boost levels for a given amount of fueling...generally speaking.
Each housing size DOWN you go you can expect to see **about** 2-3psi more boost with no other changes.
You will also see slightly less temps at idle and up with a smaller housing because even at idle the thing will be moving more air into the engine than the larger housing was/will.
BTW, who was it that built the pump for you???

regards, bob....

 

"BTW, who was it that built the pump for you???"

Hey Bushy,

Bradleys Diesel did the rebuild on the pump.. They are the same guys that rebuilt Stomps pump. Boy does that truck move

On the temp at idle, mine is just the opposite. In D the temp is high and in N or park it will go down to 300* F

Would the TC on mine have anything to do with the EGTs??????

Thanks

Larry

 

Hey Larry it was nice to meet you. You have a nice clean First gen. I want to throw this out to everyone. How about his timing? That could have something to do with the high egt's too right? His boost does seam up to par for a relitively stock set up. So I dont think that there would be a boost leak, but I could be wrong. It would be a good idea to check it. Have you tried anything yet?

Stomp

 

I have an interest in this one, because I have exactly the same problem. If I leave it in drive, I'm up at about 375-400F. If the A/C is on, it is over 400F. The only way I can get it down to 300F, is put it in park or neutral, turn off the A/C, and even then it takes a couple of minutes to creep down to 300F. I tried setting the idle down to 700 rpm, but while it helps, it doesn't help much. I do have the timing set as far advanced as I can twist the pump, and that appears to be about 3/16". I would rather not set the idle any higher, since if I set it at what everyone says I should, i.e., about 850 rpm, then sitting in drive at a light will drive my transmission temps up real high.

John