IH 1600 Loadstar Problem

I"ve got a 1974 IH 1600 loadstar with the 345 gas engine in it, it has a problem i"ve yet to figure out and thought maybe you guys might could help me out. When the truck gets hot after being driven and you cut it off, 4 times out of 5 it will not start back, it will turn over but will not fire. Funny thing is its getting fire and gas. If you pull it off it starts right up. I"ve changed the coil, plugs, plug wires, condenser, rotor, dist. cap, checked the timing and set the points and it still does it. It doesn"t do it unless the engine has been run and gotten up to operating temp., its just more aggravating than anything. Anybody had one do this before????

Is the starting bypass circuit from the "R" terminal on the starter solenoid to the (+) terminal on the coil intact and functioning properly?

What is the voltage at the (+) terminal of the coil during cranking?

You are likely right on for his starting problem. The other thing might be the gas in the carb is boiling and floods the engine while it is stopped. Our new gas boils a lot more than when that truck was new.

I have a 1968 Dodge C600 that was doing the same thing! Drove me nuts! I changed every thing you could think of and then some and still would not start hot. This went on for 3 years. I found the owners manual and found out that the parts place had crossed the plug numbers wrong! I got the plugs that the owners manual called for and now she starts everytime hot or cold. I would do some reading to make sure you have been given the right parts. Like others have said about the gas boiling easer now, Do you have a Stainless Steal plate with a gasket (1/8" top and bottom) under the carb? This will block heat from the engine and will run better, Sounds dumb but it works. Hope this helps you. Bandit

"IF" you have a darned good battery and cranking is not an issue, I'd sure be thinkin' about giving it a compression test.

To verify, advance the timing 10°. If it then starts 'better' hot, you've probably got a tired engine.

Allan

If the card is boiling ,try putting an electric fuel pump on with a 'momentary'switch.Thatway you can fill the carb with fresh gas.Just a thought....

Check the distributor shaft to see if its worn out. Not all that uncommon with those old Binders. Had a 75 that about drove nuts. Got a new distributor out of California and cured the problem.

fuel lines in the fuel pump frosting ? --- Vapor Lock ???

We have one, sitting in the weeds now - only because there are a couple of old Louivilles which run better. My guess it is the "gold box" on the fire wall. I think it is on the passanger side under the wipers.
I'm not sure what that box is for but it has four or five wires comming out of the sealed box - I imagine it has relays or something inside. Anyway, when we had trouble and after doing all you had done I went to a used parts place and found one. We replaced it and it ran fine.
Just my guess??? Grant

I recall a heat saturation problem with the starter motor. As I recall, the exhaust from the center of the right side manifold angles back towards the starter motor and comes close enough to really heat it up. I think earlier models had the exhaust pipe coming more straight down and thus being further from the starter. If your pipe is within 1 or 2 inches from the starter, then heat is the likely problem. The simple no cost solution is to make a sheet metal heat shield and use stainless steel hose clamps to hold it to the down pipe. When the starter is way too hot, it draws too much current, and the voltage to the electronic spark is too low to fire the plugs. The older mechanical points performed better in these marginal conditions.

But there is also a heat/vapor problem with the fuel pump located at the lower right front of the block. It also can be affected by the heat of that same exhaust pipe. Today's gas turns to vapor at lower temps than any gas in use when these trucks were the common workhorse of the farm. Some guys get around this problem by using an electric fuel pump located close to the fuel tank, and bypassing the mechanical fuel pump. And then shielding the fuel pipe to the carb with tin foil wrap.

Good Luck.

Paul in MN

Hey guys, i put a electronic fuel pump on it already, i thought it was vapor locking but that wasn't it, i do notice that the sound of it cranking is a little different when its hot vs. cold. i'll look at the exhaust and see how close it is to the starter, i was wondering about the flooding issue, would it help to rev it up a little before i turn the switch off???

where do i get one of those gaskets at???

(quoted from post at 22:33:37 05/29/11) I"ve got a 1974 IH 1600 loadstar with the 345 gas engine in it, it has a problem i"ve yet to figure out and thought maybe you guys might could help me out. When the truck gets hot after being driven and you cut it off, 4 times out of 5 it will not start back, it will turn over but will not fire. Funny thing is its getting fire and gas. If you pull it off it starts right up. I"ve changed the coil, plugs, plug wires, condenser, rotor, dist. cap, checked the timing and set the points and it still does it. It doesn"t do it unless the engine has been run and gotten up to operating temp., its just more aggravating than anything. Anybody had one do this before????

Click to expand...

I would check valve settings. It sounds like compression issue.

This engine uses hydraulic lifters.

I don't think the revving before turning the key off will do any good. Usually the engine is running faster when the key is turned off, and thus it continues to suck raw gas into the cylinders without burning it. So it is partially flooded by this process. The IH 304,345,392 engines were bears to get unflooded. They seemed to wet the spark plugs with raw gas. When faced with that problem, I'd wrench out a few plugs and heat the tips with a Burnzo torch, and then pass the torch past the open plug hole for a good BARK!! Put the plugs back in and it would start right away. As I think about it, my IH trucks had many more flooding problems than any other brand I owned. Maybe the Holley carb needs a heat shield under it.

Paul in MN