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Cooling System Overhaul - Stumped and Frustrated

235* is definitely higher than I'd want to see. That said, GM was using 240* as the "oh crap" temp on the small blocks with electric fans, so you've still got a BIT of a margin I suppose, but still, that seems much too high.

Outside of watching what is going on with fueling at WOT, I can't think of anything you haven't done.

I'm pretty sure somewhere in this saga timing was addressed.
 
dyeager535 said:
235* is definitely higher than I'd want to see. That said, GM was using 240* as the "oh crap" temp on the small blocks with electric fans, so you've still got a BIT of a margin I suppose, but still, that seems much too high.

Outside of watching what is going on with fueling at WOT, I can't think of anything you haven't done.

I'm pretty sure somewhere in this saga timing was addressed.
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I was considering timing also. Addressed, who knows.

I have set it properly at 4˚ with the electronic advanced properly disconnected.

Stock spec is 0-4˚, and i set it at 4 after having pinging issues on my last TBI truck when set at 0.

Do you suggest it be set somewhere else?

I know some TBI guys run different timing, but i haven't ever read into it enough to do anything with it.

In regards to the 4˚ reference, i dont' remember if its advanced or retarded, but the timing tab on the tbi motor only reads one direction.
 
It seems like *most* GM stuff was running 0* base, but not all. What is the spec on the core support? Is it actually a range?

I doubt timing is causing this much of a problem honestly.
 
dyeager535 said:
It seems like *most* GM stuff was running 0* base, but not all. What is the spec on the core support? Is it actually a range?

I doubt timing is causing this much of a problem honestly.
Click to expand...

The spec for smog, which i think is factory spec, is 0-4˚.

I never had an issue specifically running this truck at zero, but went straight to 4˚*to avoid the pinging i had on my other truck.
 
Operating under theory here, not what I think is reality in your casenecessarily, at 4* advanced if fueling is still not optimal you COULD be running into the knock sensor under load, which would retard timing, which would hurt power. But that doesn't explain the heat, and from what I've experienced, when I hit the knock sensor it feels like the truck hit a wall. I'm not sure about the TBI setups but the amount of timing pulled can vary, so it would be possible that just enough is pulled to reduce power a bit, and not be so noticeable. IIRC, most people say that 4* is about as much as you can normally get out of these things without running into other problems.
 
Ok, so we have a development.

I left the boat in Tahoe last weekend, so drove up unloaded tonight.

Disconnected the o2 sensor, and..... It did Nothing. No check engine, no noticeable open loop, no temp difference, no fuel consumption difference.

So, either the computer I replaced a couple years ago isn't reading the o2 sensor right, or the sensor wire is grounded somewhere and providing a false reading to the computer. Cause come on, there is Nothing connected. And not even a cel after 260+miles.


I'll reconnect it, and trace the wires.

Probably wouldn't hurt to toss a multimeter on the harness side of the sensor wire. Anyone know what it should read?


Let's figure out this problem!
 
Funny is an understatement. Something is very wrong there. Wrong computer? Wrong program? Damaged computer? Damaged harness? Totally failed sensor ?

Ok preface, I've never owned or worked on a TBI engine before. But as a professional mechanic troubleshooting is not an art. It's a science. Divide and conquer to find a problem.

Now that said. I'm my hands on experience if a problem just sort of pops up after you've done some thing to a vehicle or machine 90% of the time it's something you did or forgot to do.

Are you 100% sure you wired this new sensor correctly?

Then systematically go through and provide what it's not. You will eventually end at the root of the problem.
 
Also a chassis schematic is a must. As an apprentice one of my first journeymans favorite sayings was if you don't have a schematic you're not troubleshooting. You're guessing.
 
You might try PM'ing EagleMark about the O2/CEL. If something was terribly wrong with the ECM, your CEL wouldn't flash twice when you turned the key to "run".

I seem to recall at least a few people saying they drove TBI rigs with no O2 sensor and no codes, so I'd find out if that is really indicative of anything or not.
 
Did you disconnect the battery at some point? Cause the computer stores information from the o2 and populates "memory cells" in the computer for it to go to. So it would remember where the o2 told it to go fuel wise the last time that cell was populated. But it sure seems like you should get a code at some point. But maybe not?
 
In other words, it's not surprising that it wouldn't run differentif you ddidn't disconnect the battery first to clear those cells and put them all to defaults. I'll send you my data logging cable if you want to do some data logs?
 
So, I pulled the ECM fuses, reset the computer, and not much happened.

CEL came on after a few min after the first start, but went away when restarted, and didn't come back on.

No further running changes.

Thanks for all your help thus far. Thinking I'll transition over to the injection section, and see if someone can help troubleshoot this issue from over there. Maybe some info on the o2 sensor, maybe some wideband data logging.

Who knows.

http://coloradok5.com/forums/showthread.php?p=3438956#post3438956
 
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y5mgisi said:
Worth it! Doesn't say if it's a 454 or 350 tho.
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Don't encourage me.

Grass is always greener on the other side.

I'd love to be all over that truck, but it would mean that i'd finally be making the switch away from the 91, and probably wouldn't be able to keep it much longer.

Going to keep an eye on it. He won't get anywhere near $4500 for that thing in this market. If it looks like i can get it in the 3 range, we'll see.

99% of those were 454's
 
1.5 yrs after install, the Champion radiator is leaking between core and tanks.

F*ck.

Chatting with them tomorrow regarding warranty coverage. Hope they will ship me a new one, then deal with my return testing. I need a new one NOW.
 
Probably add another page to this thread (pretty epic already) but I wonder if that is due to the radiator itself, and/or the movement of the core support?

I'm really curious how much force is imparted on the radiator. Theoretically the core support is isolated from the frame, and I don't recall any common issues that would be attributed to stress on it, but as much as the frames move it wouldn't surprise me if it worked the radiator mounts a bit. Heck, even "loose" engine mounts would put extra stress on the radiator through the hoses moving.

Could also just be a shoddy job on just that weld and you are unlucky. Or they are all way too thin and will fail in a short period. I hope the last is not true, as I have my Champion sitting in the garage ready for my testing....eventually lol.

Would probably be valuable to know the thickness of the various components on a champion vs some of the higher end aluminum radiators.
 
dhcomp said:
1.5 yrs after install, the Champion radiator is leaking between core and tanks.

F*ck.

Chatting with them tomorrow regarding warranty coverage. Hope they will ship me a new one, then deal with my return testing. I need a new one NOW.
Click to expand...

Yeah, I've got a leak too. Some where down where the lower hose connects. I'm betting were the plastic tanks connect to the aluminum core. If I would have known the side tanks were plastic I wouldn't have bought it.
 
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