Fuel, or Spark issue?

Wayne64 · Post by **Wayne64** » Fri Nov 21, 2008 2:28 pm

The M37B1 that I just bought has some problems. Yesterday was the first time I tried to start it (no clue how long it had been sitting, but did have a 2008 inspection sticker). It would start but only with the choke full on and it wouldn't take the throttle. Ran rough and never would idle without the choke full on. Give it the pedal and it would stall. This truck had a Carter electric fuel pump installed on the inner fender. Not a place I would mount one as they push better than they suck. I pull the inline filter before the pump and got water. Today I drained the carbs fuel bowl, added a new filter and used my 6 gal boat gas tank with fresh fuel. I ran the pump to check output and to clean out any water from the pump into a container before hooking up the carb. I started it again and it ran rough but it would idle with the choke off. Still will not take the throttle without stalling. The carb looks to be a rebuilt one and since this passed though another's hands I have no history.

MSeriesRebuild · Post by **MSeriesRebuild** » Fri Nov 21, 2008 8:50 pm

Sounds like a very possible carb issue, I would disassemble, thoroughly clean, & rebuild the carb. You are correct about the fuel pump, it needs to be frame rail mounted near the fuel tank.

k8icu · Post by **k8icu** » Sat Nov 22, 2008 8:32 pm

I'd have to say it sounds like a fuel issue.... You have spark since you can make it make noise and run but when you try to increase RPM you die. It's not timing because it wouldn't run if the timing was off. I would start with giving the carb a good cleaning. I know my M151 would do the same thing after sitting a long time. Old fuel shallaced in the carb would make it not run worth a darn. Clean the carb and it would run just fine.

Wayne64 · Post by **Wayne64** » Sun Nov 23, 2008 1:00 pm

I'll pull the carb maybe this week, but a question first please. When buying a rebuild kit, which I see for sale in a few places, do I have to worry about the quality of the kit ie; was it made recently or can I go with NOS? The reason I ask is because I remember back to when our state started adding MBE to the fuel and then we went to E10 year round and certain original components couldn't take the additives. Fuel pumps and carburetor parts died at an early age. The E10 fuel is why my M37s tank is loaded with water BTW, I hate the stuff and being a boater we have been fighting this problem for a number of years.

mattveeder · Post by **mattveeder** » Sun Nov 23, 2008 1:16 pm

I will agree with the others it sounds like a carb issue. Mine was the same way as yours. But after rebuilding the carb I still had other issues. I had found that the mechanical advance in the distributor was stuck. It was like a new truck after that.

MSeriesRebuild · Post by **MSeriesRebuild** » Sun Nov 23, 2008 4:54 pm

I would definiately stay away from NOS kits. Going with a current production kit will be fresh & compatible with todays fuel. The gaskets in a NOS kit will deteriorate when used with todays gasoline. We have been using kits from Tom Howell, Snake River 4X4 with very good luck for several years now.

Wayne64 · Post by **Wayne64** » Sun Nov 23, 2008 6:19 pm

Thanks much Charles, Snake River gets a call in the am.