M135 throttle hesitation

[n1bnc]

All.


It runs!!! I now have the M135 in the driveway and plates are coming Tuesday. Tires on wednesday, and the brakes bled on Thursday. Off to a ham radio party on Friday!!!



I have noticed that the truck idles well, but there is a hesitation when you hit the throttle. The Carb is brand new and the accelerator pump is indeed hooked up. Give the throttle a couple of blips and you can get the engine to rev up okay.



I have not done anything to the ignition system as it seems to be okay. It did not like the old gas in the tank so I removed the really awful looking gas (green? :shocked: ) and threw in several gallons of the fresh stuff @ $2.13 gal (grr). Once the fresh stuff was in, it fired off on the second crank.







Thoughts???

 

[Westech]

could be a vac leak, or the timing is too retarted. spray brake cleaner around the intake and carb base, and if it reves up a tad there is your vac leak. NOW BE BRAKE CLEANER WILL GO POOF ( BIG FIRE BALL) SO LOOK OUT! but it works great for finding leaks.

 

[deuceman51]

Not sure if this could be part, but possibly your fuel pump is not providing the right pressure. I think it is between 2-3psi, the manual has that in there. I would definately take your fuel pump hanger out of the tank if you haven't done that already and clean the heck out of it. I've never heard of green gas, but it can't be good. My m211 had 2 year old gas in it and it turned to varnish and gummed everything up inside. It was a dark yellow almost orange color. I took the entire assembly apart and used paint stripper to clean off the varnish that coated everything. It also gummed up the pump and ruined that too. Good luck.

 

[Cheek]

Hello Nat!
It's nice to see a fellow Amateur Radio Operator On Here! I've been a Ham since '77 and have really enjoyed it! Good Luck on your latest project! I really like your truck! It looks cool with the hard top!

Take Care!

Jeff WD4IHS

 

[n1bnc]

All,



Instead of brake cleaner I used starting fluid as it was sitting near by. i couldnt find any leaks around the carb, so i tweaked the timing a smidge. the truck will make its maiden voyage tommorow night around the block. the tank has a fair amount of fresh gas in it now. i am hoping the swill i drained out was enough to make a difference. the exhaust does not smell so nasty anymore. i will have to watch it in the future. i wanted to take the tank off and have it cleaned professionally but i need the little bits to put it all back together and i didnt want to disable the truck just after getting it on the road.



for Jeff, the truck's intended use will be for camping @ fleamarkets, and carrying the necessary parts for a vhf contest. i plan on carrying 30' of tower and some mast for two or 3 antennas depending on the bands i would mountain top with. i am still getting the parts together, but the m135 was the first piece!



i will have more pictures when available.



this weekend was spent cleaning out the cooling system and replacing hoses...

 

[Westech]

good luck with her. I hope she runs good after some good gas. I do love the sound of the 300 st6, its just cool.

 

[M543A2]

If you got crud out of the cooling system, I would recommend checking the tranny cooler if you haven't already. Looking at the front of the cast iron tranny oil pan you will see a bolted on oval cover. Remove it when the system is drained and wash out the cavity. You will see plugs marked oil and water on the bottom of the tranny pan. Dain the coolant by removing the water plug. Since this is at the lowest point in the system, a lot of crud gets in there and tranny overheating results. Also, I, and I would guess your transmission shop would highly recommend not using engine oil in the tranny. Go to Dexron, or a good oil rated for Allisons. I did this in mine, and got many trouble free years of use under hard pulling conditions. Engine oil just does not have the qualities necessary for long life in an automatic tranny. The military did it because it made the supply/inventory problem simple.

 

[j land]

i had a similar hesitation problem with mine ,the problem was that the distributor was loose and kept moving on me , i didnt find it til i went to replce the points and condenser once i timed it(i did it by ear) she runs great now thank god. i hope it helps you

 

[M215]

I also had some of the same problems with hesitation after installing a new (rebuilt?) carb. purchased from White Owl in NC. How long did this thing sit on a shelf, 20-35+ years? Installed a fresh rebuild kit from Menphis Eq. and it runs great. Some times these re-build kits can be difficult to find, I plan to keep one on hand for future use.