100 DEGREE TEMP, WRECKED ENGINE??

[LVJJJ]

Just got back from camping at Bend OR with the '94 GMC k1500 Burb in which I installed a 383 stroker in 2019 and its got 13,000 miles on it. We live in Blaine WA so it was a 1000 mile round trip towing a 4500 lb travel trailer. The 383 ran great until Sunday. That day in Northern Oregon and southern Washington temps stayed at 100 degrees all day. Hwy 97 is seriously up and down all the way from Bend to Yakima where we camped the first nite. Toward the end of the day stopped for gas and the engine died before I could shut it down. Then it hardly started, had to rev it to 2000 rpm to keep it running, after a few minutes it would keep running but it was idling a lot faster than it used to over 1000 rpm. Been idling at 3-500 rpm in gear to out of gear. So, we made it home but starting it was always a challenge. It never overheated and the Tranny only got up to 200 degrees for a little while, most of the time it ran at 180. Got really hot in the engine compartment but nothing melted, got headers but removed the splash guards and front rock guard to get air into and out of the engine compartment.

Had the chip reprogramed by OLD EFI and we had it perfect. Wonder if I glitched it somehow? The check engine light came on for the first time ever when it was idling after start up. Once we got underway the light went out. Seems to run good as usual once you get going but still idles too fast. Any ideas of what might of happened????

this sounds a little like MotoDude's thread he just posted.

 

[LC2NLS6]

Check fuel pressure is what I'd do first. Then verify indicated timing.

 

[L31MaxExpress]

Check to be sure the distributor clamp has not become loose letting the distributor retard itself.

 

[mr_josh]

Did you check to see what code was thrown? I'm wondering if it's EGR related.

I took my '97 K2500 with camper up US 97 from Oregon to Yakima back in June when it was 110 degrees out. I had forgotten what a climb that is.

 

[Schurkey]

Verify fuel pressure, connect a scan tool so you can find out what the computer is trying to tell you.

Anything else is guesswork.

Removing the airflow ductwork was almost certainly a mistake.

 

[LVJJJ]

Gonna take it to my favorite GMC dealer, small town dealer here in Lynden where I know all the staff. They have one of the best diagnosticians in the world. Is a friend of mine who helped me install a 292 in my 1965 Chevy Van back in 1988. Van still running still towing if necessary, with 90,000 miles on the 292.

As for the airflow ductwork. Have to disagree, not sure why you would say that. Is one of the best things I did for more power. Made a huge difference in power and didn't get vapor lock anymore. CAn't see how enlarging the intake from a 3" hose to a 4" would be a mistake. Done that to all of my tow vehicles. According to a local technician who used to teach truck repair at the Chevy truck plant in Detroit, the purpose of the big air box was to quiet down the sound of air intake, so it robbed power while eliminating air intake sound, which i happen to prefer. So suggested I toss it. Did.

 

[Schurkey]

Got really hot in the engine compartment but nothing melted, got headers but removed the splash guards and front rock guard to get air into and out of the engine compartment.

As for the airflow ductwork. Have to disagree, not sure why you would say that. Is one of the best things I did for more power. Made a huge difference in power and didn't get vapor lock anymore. CAn't see how enlarging the intake from a 3" hose to a 4" would be a mistake.

I wasn't talking about the air intake tube.

I was talking about the splash guards and rock guard. I suspect they're allowing air into the engine compartment, which reduced air through the radiator.

 

[LVJJJ]

oh. don't think it did take air away from the radiator as it never overheated and the clutch fan only came on once in a while. Trans temp ran at 180 most of the time. With the headers, it gets real hot in the engine compartment because there seems to be no way for air to get in or out except thru the radiator which is also hot, so been taking the splash guards off in the summer. I have found that the Burb has one of the best cooling systems I have ever had, it usually runs right at the thermostat temp and only got hot when pulling a hill. Oh, and I ran the A/C all day too and never came close to overheating. All and all its a great vehicle. Comfy and smooth running, almost forget the TT is back there once in a while. Wonder if the problem is the EGR valve?

 

[GoToGuy]

You did not say what your chosen thermo' normal temp is. When you say " never got hot" thats' too vague. What do define as hot? 10 over, 20 over, steam out the expansion tank? A trailer load, an over 100° F day, up and down hill's, and what altitude? 100° F at 3000 above sea level, density altitude is closer to 5000. This affects cooling effeciancy, heat transfer and amount of O2 for power production. The advantage we have is with fuel injection and ECM control we overcome some of these negative effects. But not all.

 

[Schurkey]

there seems to be no way for air to get in or out except thru the radiator which is also hot

Air gets "out" by going under the vehicle. If more air spills in from the missing splash guards, there's that much more air going underneath. As the air pressure under the vehicle increases, less air comes through the radiator.

An air dam directly under the rad support can make a huge difference.