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So my truck starts up and idles good but when it gets up to temp it dies. The coolant doesn’t look like it’s flowing into the top of the radiator when it seems like the thermostat should open. I’ve tried multiple thermostats and this one is a 190. My fan clutch feels like it has decent resistance also. And since I’m going to replace the water pump should I check out my timing chain?
Hello, I don't know how to tell if or when coolant is flowing; but, I hope you are certain changing the water pump is necessary... I've drained out old coolant, flushed the cooling system with cleaner, installed a new thermostat & new radiator cap and filled the system with 50/50 premixed antifreeze... The tubes inside the radiator cleaned up & opened up pretty good by flushing the system with flushing cleaner before installing the antifreeze... I top off the system until the overflow/expansion tank on the left inner fender well is half full...
My dashboard has a needle gauge for engine temp (ignition ON I've never seen a red light for temp) My temp gauge needle never got past 1/4 scale for several years, then suddenly it runs normal about 3/8 scale or a little more... Fellows here, said it was a poor electrical connection on the coolant temp sensor (I actually don't know where that sensor is threaded into the head (I think it is near the thermostat) <--- a pair of twisted wires go to a sensor in that area on my truck... My cooling fan is oem clutch type also... I don't think my truck overheats X fingers...
So, my truck began having lack of power then hard to start when HOT and now will not start at all... My mechanic friend says the carburetor is flooding the engine... We recently changed the carburetor... My truck has a good strong spark at the plugs NGK BPR5ES-11... I pulled one plug and it was totally black, too much fuel... Fellows here have said PLUGGED VENTS in the fuel bowl or AIR LEAKS at the carb to intake manifold or STICKING/open/closed NEEDLE SEAT are most likely the problem... FSM & YouTube also have info that a dirty EGR valve can cause a no start problem... My vacuum lines and all else checks out good... Maybe it's a fuel carburetor problem on your truck as well..?
So hopefully any day now I me we whoever will begin removing the oem Mikuni carburetor to try cleaning & install a kit of partial parts into it & adjust the float, etc... Wished I owned an ultrsonic cleaner BUT I wish even more that you make sure it's really necessary for you to change your water pump before doing so...
One of us is gonna win these battles :thumbup:
Aloha --
George
Leave the radiator cap off it and let it get to what should be operating temperature. If you don't see coolant flow through the cap fill hole, the pump may have failed. If it's dying when it should be hot and you're sure the pump is pushing water around the block and through the radiator, check the auto choke on the carb. If the choke butterfly is still closed, the auto choke has failed or needs adjusting. Check the condition of your plugs as George has suggested as this is an indicator of a running rich issue which has to be fuel as a primary fault, or ignition as a secondary (poor tune, big plug gaps, tired coil...) If the timing chain is noisy, I'd put a kit through it or if the engine has done a ton of miles and you're pretty sure the chains and guides haven't been touched, I'd think about doing it. These aren't interference heads so if you jump the timing it won't damage the valves, but a busted guide or chain will really make a mess in the front of the engine (you don't want to drop the sump to fish out fragments of metal and broken guides)
Well I’m changing the water pump this weekend to hopefully get some flow going. I completely rebuilt the carb and used the best parts from 3 donor carbs I have collected and cut all of the gasket clearing any blocked passages between the carb top and the throttle plate. Hopefully this will get me moving and i will update you guys this weekend
Also thank you guys very much for the insight!
The balance shaft timing chain is the Achilles heel of the G54B. Well, actually it's the balance shaft bearings. At high mileage they can seize up and snap the chain. This stops turning the oil pump, but the cam and distributor are on a separate chain so the engine keeps running. If the engine has high mileage, I would consider replacing the timing chains and balance shaft bearings, or installing a balance shaft elimination kit.
Changing the water pump is a pretty quick and easy job. You have to remove it to do the timing chains, but it's not enough work to justify doing the timing chains "because I have the water pump off"