1975 W100 360 Falls on its face under load

[buzter]

Still having issues with my 75 Dodge W100...I have since put new carb on, new coil..and replaced the alternator...when idling the truck runs like a top, but once I start moving snow with it and put it under a load, it falls on its face...any ideas..here was the previous help I got

http://www.powerwagonadvertiser.com/...ad.php?t=10845

[buzter]

I have also put in all new fuel lines and added a electronic fuel pump

[Gordon Maney]

Will it maintain highway speed?

[buzter]

It probably could..it is not a driver at all..I use it to plow snow on my acreage bout all the travel it sees..but when I run it down the road a bit...it gets up and moves good, its just that first start where it falls on its face..feather it a bit and it comes back to life and then goes

[Gordon Maney]

Did this problem begin abruptly or gradually?

[buzter]

I really can't say anymore..I have been fighting it for years trying to figure it out...bout everything has been replaced on the truck that would affect it...I'm not saying that something replaced wouldn't need adjusted..but that is where I am stuck..I have been scratching my head over this...

[Gordon Maney]

For years???


Have you done a compression test on this engine?

[buzter]

Yeah..I would say 2-3 years..thing is I use it for a plow truck and it moves maybe 50-100 miles a year...always put fresh gas in every year

[Gordon Maney]

Have you done a compression test on this engine?

[Paul in MN]

Is the carb a 2300 series Holley? If it is, I'd bet on the carb's accelerator pump. It has a large rubber diaphram attached to a metal disc. The ethanol in today's gas will destroy that diaphram in less than a year (but maybe the aftermarket carb people have come up with a better material now). Also in a passage near the center of the carb's main body is a sliding metal valve that prevents gas from being sucked continuously through the accelerator circuit. This piece looks like a needle valve in a needle and seat of most carbs. This needle can be lost if the carb is turned upside down during a rebuild. If it is missing, the accelerator pump can not work as needed.

The easy test for this type of malfunction is to have the engine running at idle with the air cleaner off and look down the throat of the carb while turning the the accelerator pedal linkage quickly a number of times in rapid succession. Look for the spray of gas that each "blip" of the linkage should produce. Of course this could result in a backfire (especially if it is misfunctioning and leaning out), so wear safety goggles or face mask.

This is a fairly easy carb to work on, and the parts are commonly available. I do not know about any Dodge specific mods to this carb, but I did have this one in many of my IH V-8 trucks of that vintage. They used this carb in everything from 1/2 T P.U. up through the Loadstars. It was on the 266, 304 and 345 cu inch engines.

I plow snow with a 88 Dodge W350 w/360 and a 4 bbl Rochester QuardaJet which has given me fits for some years now. I know way too little about the QuadraJet, and I have done similar to what you have done in replacing plugs, wires dist cap/rotor, vacuum and comp checks. I have come to the conclusion that the prob has to be within the QuadraJet.

Good Luck, and I hope you get it working better.

Paul in MN

[buzter]

I did some testing tonight
Vac off carb @15 at 1500rpm and bout say 1-2 @idle
Timing bout 2 before
Rpm 7-800

And carb is brand new and I do not run ethanol at all in it so I would not think the pump in the carb is shot or would need rebuilt

Gordon..did not get a comp test done yet..but motor has only bout 80K on it

2bbl holley..I think either a 2210 or 2245

[buzter]

Adjusted the timing a bit..have rv cam in it..so gonna take it out and plow a bit..see if it made any diff

Also checked vac on dist..good movement

[buzter]

Seems to have better power now but still falling on its face when under a load..or even starting going..feather the pedal a bit and it has all the power in the world till u get to a snow pile and give it a bit more..dies out..when backing if I slowly give it gas it is fine till I try and push it to much then again falls on its face

[buzter]

I do appreciate all your guys help on this as I am at my wits end on solving this

[Ron in Indiana]

My nephew just had this problem with an 86 Dodge. The timing chain, fuel pump and distributor were replaced. The carb was rebuilt but it stalled too. We reset the timing with the vacuum hose OFF the vacuum advance. This engine is set 12 degrees BTDC. Now it runs like a champ again. Not saying you aren't setting the timing correctly just offering up what we did to correct our problem. I'll assume the float is set to proper height.