FIGGER THIS ONE OUT

[GrampS10Acious]

Hey all you GearHeads,
O.K. since I'm not the electronics guy I should be when it comes to my truck I'd like to get you fellas to figger this out.
It's summer time and when I run my a/c my temp runs up at 198-202 degrees on the open road and when I get in traffic it spikes to 212 and then I cut the A/C off. Remember my post about Moanin' and Groanin' , well this is also part of my problem.
Now when the temp gets up to 202 and I am coming off the interstate as I was yesterday, I came to a stop and when I drove off in first gear it stumbles and acts like it is running out of gas and quits. It will start but will run about 10 seconds and quite again and will not start run and be drivable til the temp is, say, down to 198 degrees and then it will start and drive till the temp gets up and the problem starts all over again. Is there a sensor on a '92 2.8 L that has a correlation between temp and fuel delivery? When I took the breather of and tried to start it, it appeared that the right injector was running out of fuel but I couldn't get around to watch it quick enough to see it and it is only when it is acting as if it is starving out that I can see it. It's got to be a sensor or something. I am not getting a check engine light(wish I was) then I could figger it out myownself!!
I want to get a three row radiator and maybe help this but the funds are low at this time.
I always appreciate the input of this site and this is no different,
Gramps

[GrampS10Acious]

O.K. a little update, took the ignition module up to the local and had it put on the machine and checked, checked good and so I bought a coil pack cause I remember a guy that had one and it just quit going done the road....coil pack went bad.
Gramps

[JRPulley]

I too, have experienced your problems with the 4.3. So, I started replacing parts. New water pump, new thermostat (160 degree i've found works the best) turns out calcium deposits in the radiator is probably the culprit. A standard 2-row will be fine, and while you have it out, check your water pump, it's not hard to pull and it may well be worth your time. (read:cheap insurance) When you replace the coolant, do so with standard green anti-freeze and DISTILLED water.
Good Luck

[betterthanyou]

The water pump on the 2.8L is not an easy 4 bolt replacement like the 4.3L is. A 160 degree thermostat will have no effect on an overheating engine. The thermostat is not even in the equation when the engine temp is rising uncontrollably. Plus a 160* stat is just stupid an engine makes more power and runs bettwe at or above 200*F. Maximum power is made around 220*F but it is too close to overheating and does not provide a safe buffer so 200*F is the most ideal operating temp.

The engine coolant temp sensor (ECT) sits right front and center of the intake behind the thermostat housing and has a black and yellow wire. This sensor tells the ECM the temp of the motor and the ECM will adjust fuel accordingly. If the sensor is bad fuel delivery will be off.

As for your cooling issues if everything is good in the system and you will have a stock clutch fan that works then the AC should never create enough excess heat to make the engine warm up. My Trooper has a smaller rad and and E-Fan and I can drive all day is the scorching sun with the AC on and the temp stays around 200*F. Since you said freeway driving keeps the truck cool I would suspect a fan or rad problem.

[JRPulley]

I can only say that what I did works for me in the Florida heat. And, you and I came to the same conclusion as far as a radiator problem.
Far too many times people use tap water in their anti-freeze mixture, distilled doesn't cost much and it reduces calcium deposits.
So, to close this subject, I will simply say that everyone has an opinion, and how dumb you are depends on where you're standing.

[GrampS10Acious]

As always alot of good insight on my problem.
Was wondering if I went to a 4.3 Rad with my twin fans would be any better? I read on the V-8 S-10 website that some are using the 4.3 rad for their V-8 swaps, ...is it bigger than the radiator from my 2.8? I run 198-200 degree and when I come to a stop it will spike to 212- 214.
Thanks,
Gramps

[neo71665]

The inlet and outlet are on the wrong sides for a 2.8 and any other chevy rad.


Fords now did have them backwards (like other things) so you might be able to find a bigger rad out of one of those.

Personally I have the "heat buster" from autozone in my blazer and it works just fine. Three core and fits in the factory spot.

[jwvess00]

Hi there!

Is 212 as high as it goes, or is that just as high as you'll let it go before taking action? 212 isn't too hot. Iron head engines can take a surprising amount of heat without damage. Even the aluminum V6/60s didn't turn on the fans until 227 or so.

Your stock-ish 2.8 should be fine with the stock radiator and fan. I see no reason to go to a bigger radiator. The 2.8 S-series doesn't have a known problem with overheating.

Make sure all baffles and seals around the radiator and hood are in place.

I have had stock replacement thermostats be bad, new in the box. I only use name-brand thermostats now. I do not consider Stant to be a name brand...

The coolant temperature sensor is threaded into the intake manifold, two wires, close to the thermostat. I've seen quite a few broken ones and that can cause some goofy drivability issues. The connector shell on the sensor itself should not be loose. Because of their location they are easy to hit with tools (I've done it, and I while try to be careful, stuff happens), and the connector becomes damaged.

You mentioned twin fans -- have you installed an aftermarket electric fan setup? Are you sure it's working properly? Has the truck performed properly in similar driving and weather conditions with this setup?

If you still have the stock clutch fan, I'm wondering if it's working.

If the radiator doesn't leak, it may be prudent to take it to a radiator shop and have it flushed. It's possible you have a water pump problem, but when they fail they almost always just leak.

[GrampS10Acious]

Well it only spikes to 212-214 when I have the A/C running and when it does I cut off the A/C. I have never let it go to see if it will continue to climb, guess I could just to see how hot it will get. I do have a twin electric fan setup on it and to tell you the truth I have an issue with one of the fans not coming on at times and it will run slower than its brother. The company that I bought them from have a lifetime warranty on them and they have replaced the motor. I remember that I had the same issue with the old clutch fan, it would spike up to around the 210 degree mark on the "old" dash gauge with the A/C running and to tell you the truth that is one of the reasons I went to a aftermarket gauge setup. I'll swap out the bad fan motor and see if it improves.
BTW, what is a good brand of thermostat?
Thanks,
Gramps

[jwvess00]

Hi there!

With the stock 192 degree thermostat, my '82 registers to the center of the gauge (I'm guessing ~210 or so) before the thermostat opens, then it falls back one tick and holds there. That's typical. Seeing it spike to 212 or so is okay. Like I said, GM doesn't even bother to turn on the cooling fans on the aluminum-head FWD V6 cars until about 227 degrees.

[GrampS10Acious]

O.K., then I won't be so concerned in the future. Will watch it.
Thanks,
Gramps

[922drHoe]

yep, as said above...if it's only getting to 212-215, it's fine. just make sure your fans are working like they should be and you should be fine. i was gonna say "check your ignition module" but i read you already checked it and replaced the coil, remedying the problem...

[GrampS10Acious]

O.K. I'll go with what you all say, now let me throw another twist on this, What about a set of underdrive pulleys, would that compromise engine cooling any?
Gramps
Oh almost forgot, I changed out the bad fan motor and installed a new controller and it seems to do some better. Fans kick on at the determined temp and stays around 198-200 till I come to a red light and stop and depending on the outside temp it will slowly creep up to 214 degree. I am going to do a cooling system flush on it today and replace with new antifreeze and see.

[betterthanyou]

If you don't live in an area that freezes then run straight water and a bottle of Red Line Water Wetter or Royal Purple Purple Ice. This will provide better cooling and the additive will protect the system from rust and corrosion and help cool even better.

I would not recommend underdrive pulleys in a hot area especially if you use the A/C it will decrease low speed performance of every belt driven system.