[FIXED] Dies under load, now won't start.

[ErikTande]

A few days ago the motorhome started stalling when driving.   I took it for a drive tonight to test some things out and it really doesn't want to make it more than 40 yards or so before dying.   Here's a video of the problem:

https://youtu.be/lW_8fBbzRiM

I changed the fuel filters under the frame a couple days and that didn't seem to have any effect.      I tried to drive it today and the problem got worse, and got to the point to where now it won't start.  It doesn't seem like it's getting fuel at all.   If I spray a little fuel into the carb it fires up but wont stay running.   

What should I look for next?

**EDIT**
This pump is on the passenger side in the middle.   Should I hear this running when the ignition is on?



And here's a pic of the carb.  I'm not seeing any fuel spraying when trying to start it.   I took the little filter out of the carb to make sure it wasn't clogged, no change.



Thanks!
-Erik

[Rickf1985]

When you pump the gas pedal does anything come out in the carb? If yes then there is gas. Whether the pump runs all the time depends on whether it is hooked into an oil pressure safety switch. If it is then it will only run when there is oil pressure or when the engine is cranking if it is hooked up correctly. You need to determine if this is gas or spark, it sounds like a bad coil but HEI coils seldom go bad. If there is no gas in the carb the run a jumper wire down to the pump and hook it to the positive of the pump and to a hot wire on the coach, preferably the battery. The pump should now run and give you gas. If it does then you need to trace the hot wire back and see what it goes to. This was an aftermarket setup and all options are open here. Could be a relay, SHOULD be a relay but need to know what is triggering the relay. Another thing to check is if the pump is running and you are not getting gas is you may have a crack in an old line between the pump and the tank, after all, those lines are only 25-30 years old. W%

[Rickf1985]

I just watched your video and it definitely appears to be lack of fuel. Obviously you are getting some because it starts back up and goes a little way so the pump is doing something. Here is what I would do, find a section of line before or after the pump that is not too long and is flexible line. Determine what size it is and go to the hardware store and get that amount of clear vinyl hose and some clamps to fit. The outside diameter is usually bigger for the same size inside so you will probably need bigger clamps. This is only temporary since this hose will not stand up to gasoline for more than a month or so. But put this line in before and after the pump and then lay under there with good lighting and have someone, preferably who likes you, start it up. You are looking for air bubbles in the line and that will tell you if you are pulling air somewhere down the line. If you do see air then you are probably going to have to drop the tank and replace all of the lines up there. It would be a good idea to do that anyway considering the age. If you determine that the pump does run the whole time the key is on then another thing you can do instead of the hose bit is to take the line off of the carb and put it in a can and turn the key on. You should have a strong flow of gas coming out of the line with no air bubbles.  I am going to bet that you have a weak flow and if you submerge the end of the line you might see air bubbles along with the gas.

[ErikTande]

Good news!  The pump was bad.   I applied 12v to it directly and it still wouldn't come on, checked the electrical connections and they were good.   Got a new pump from NAPA and popped it on and it runs like  a champ now.

Both the filters I changed were pretty gunky, and check out the filter in the old fuel pump:

yikes!!








Also,  I had to drop the storage compartment to get the bolts off the top of it.   I would have just unbolted the bracket which would have been easy, but it was welded to the frame.   WHHHHYYYYY??? lol

Thanks again for the help! : D

[Rickf1985]

Did you put the same type of pump back on? I hope you didn't use one of those little square ones!

[Froggy1936]

I use one of those little square ones for my generator, It has been working and dependable for 10 yrs, But i would never trust one for main engine supply . There i only use The best available !  Frank

[Rickf1985]

A 454 at wot will be gobbling about double the gas that one of those little pumps can handle. Picture a full half gallon jug of gasoline and now just start pouring it out at a nice steady stream that will fill a drinking glass in about 20 seconds. THAT is wide open throttle on a big block.

[ErikTande]

Yep, same pump.  It was like $70 at napa.  It came with the smaller hose fittings though so I had to buy a couple 1/2 inch barbed connections with it.   I replaced all the fuel hose around it as well.