Case 1825 gas runnability issues

[turbodwg]

I'm working on a Case 1825 with the nissan gas engine. It had an intermittent misfire at all r.p.m.s along with dying when idled down from high r.p.m. I found 2 plug wires arcing to the cylinder head and the contacts in the distributor had corrosion on them. I've cleaned the contacts and replaced the plug wires. The intermittent misfire seems to be cured but the dying at idle is still there. It will also intermittently fluctuate r.p.m., like to a lower idle, while the machine is just sitting there running. Carburetors are not my specialty any thoughts or things to check would be greatly appreciated.

 

[mrbb]

check compression!

 

[turbodwg]

check compression!

I can do that tomorrow but wouldn't low compression cause a hard cold start? It fires right up cold or hot

 

[mrbb]

low compression can do a lot of things, and IMO is one of the things you want to rule out when problem solving issues!

 

[ryguy22]

I'm working on a Case 1825 with the nissan gas engine. It had an intermittent misfire at all r.p.m.s along with dying when idled down from high r.p.m. I found 2 plug wires arcing to the cylinder head and the contacts in the distributor had corrosion on them. I've cleaned the contacts and replaced the plug wires. The intermittent misfire seems to be cured but the dying at idle is still there. It will also intermittently fluctuate r.p.m., like to a lower idle, while the machine is just sitting there running. Carburetors are not my specialty any thoughts or things to check would be greatly appreciated.

I would also check the governor. I have the same exact one and I found the governor needed rebuilding. Also you can get new carbs for them fairly cheap considering. They are 2 barrel rather then a single barrel but it works just fine on mine you will have to remove the plate that blocks off the other side of the intake for it to work but that's all I really had to do for it to work

 

[06Ram3500]

Check the fuel filter

 

[ward]

I had an old nissian pu truck that had the same issue the carb had been replaced it turned out that the carb was lose and screws holding the carb together were lose, once I tightened everything and replaced the carb to manifold gasket it was fine.
Note when I mean lose you could easly move it by hand, I noticed it when changing the air filter.
Also something to think about is the unit at the correct RPM at idle, the idle postion screw will wear with age causing the engine to run at a lower rpm it might need just a 1/8th to 1/4 turn on the screw.
Back story to the PU was it came from Tennessee off a farm had been used to run to the store and running around the farm had about 15,000 miles on it and original oil filter and was rollled while trying to herd cattle in a field, the farmer bought a new nissan and sold it to the guy I got it from who had it takend to a shop where they banged out the big dents replaced the carb and serviced it, the guy I bought it from kept it about 10 years and sold it to me it had over 180,000 when it just lost power one day and was using oildue to low compression also known as blow by
compression loss can be caused by valves and this can also cause it to run rough and lower RPM then specs.
I had a 1973 Dodge with a slant 6 had burned valves on #1 and # 6 cylinder took the head off and to a shop and when I reinstalled I had to readjust the RPM as it idled at almost 1000 rpm.

 

[turbodwg]

Check the fuel filter

New fuel and air filter, and new gas in the tank

 

[06Ram3500]

I've seen where the idle screw meets the throttle shaft stop that the stop will start to bend causing the idle to drop too low and the engine cuts out. Had 2 such incidents happen.

 

[Lucy Green]

Check for vacuum leaks, dirty idle jets, or incorrect idle mixture.