1987 Coachmen Crusader Class C Stalls while driving

[toneandrox]

-Chassis info: Ford Econoline E350 460 engine V8
-It is a carburetor and uses gas
-Looks like previous owner removed mechanical fuel pump and replaced with electrical pump
-When vehicle is idling it will run forever without issues, even if I rev up engine
-When I start to drive, shorter distances now, it will sputter and gradually lose power until it shuts off. Early on it would start back up quickly, now it has to sit awhile before it will start .
-It appears to be more of a problem on inclines.
-We changed oil, radiator fluid, oil filter. We haven't changed the fuel filter yet because it is stuck in place and we need to get it off.
-We checked the fuel pump relay and it clicks when ignition is in the on position but the female connector to the fuel pump relay is dirty inside and we see some moisture in the connector. We were able to clean the connector a little. The relay appears to work because it clicks.
-There is a solenoid near the battery that we have to tap sometimes to get the vehicle to start, but I don't know if that solenoid would cause the vehicle to cut off once the vehicle is running.
-There is also a modification switch on the right side of the radiator that we are not sure what it is or how to tell it is in the on or off position. I attached a picture of that switch. It attaches to that little cylinder and then 2 large cables run to what appears to be a fuse and then runs to the battery. I've attached a pic of the little board/fuse the cables run to.

Any help is appreciated.

 

[Ksouers]

Initially, what you describe sounds like vapor-lock. Carbs are prone to it because they require a small bowl of gas to operate. The carburetor absorbs heat from the engine causing the gas to boil away before it can be mixed with air. This heat can also happen anywhere along the fuel line so that when the hot gasoline reaches the bowl it will evaporate once it's no longer under pressure.

It sounds like the DPO (dreaded previous owner) may have rerouted the fuel line, since there is an aftermarket fuel pump. Check for any fuel lines that might be placed near or on the engine or exhaust. If so, move it elsewhere away from any heat source. Second, redirect cool air to the body of the carburetor using a large diameter hose.

You may also have a clogged fuel and air filters. Find and replace. This would be a good idea anyway, especially if the vehicle is new to you. If you have an inline fuel filter make sure it is after the electric pump.

If the fuel lines are old you may have debris or scum built up in the fuel lines. Replace them.

Also try some Gumout carb cleaner and fuel additives. Carbs are quite sensitive and small issues like varnish build-up can easily cause problems.

Start with the easy stuff first, filters, old lines routed away from heat. Mitigating other heat sources can get complicated. Carburetor problems can get complicated.

Good luck and keep us posted.


Kevin

 

[toneandrox]

Initially, what you describe sounds like vapor-lock. Carbs are prone to it because they require a small bowl of gas to operate. The carburetor absorbs heat from the engine causing the gas to boil away before it can be mixed with air. This heat can also happen anywhere along the fuel line so that when the hot gasoline reaches the bowl it will evaporate once it's no longer under pressure.

It sounds like the DPO (dreaded previous owner) may have rerouted the fuel line, since there is an aftermarket fuel pump. Check for any fuel lines that might be placed near or on the engine or exhaust. If so, move it elsewhere away from any heat source. Second, redirect cool air to the body of the carburetor using a large diameter hose.

You may also have a clogged fuel and air filters. Find and replace. This would be a good idea anyway, especially if the vehicle is new to you. If you have an inline fuel filter make sure it is after the electric pump.

If the fuel lines are old you may have debris or scum built up in the fuel lines. Replace them.

Also try some Gumout carb cleaner and fuel additives. Carbs are quite sensitive and small issues like varnish build-up can easily cause problems.

Start with the easy stuff first, filters, old lines routed away from heat. Mitigating other heat sources can get complicated. Carburetor problems can get complicated.

Good luck and keep us posted.


Kevin

Thanks Kevin. We will follow your advice. We will post an update.

 

[TheBar]

Kevin is right and it sounds like a fuel problem. Since the previous owner removed the mechanical pump they may have had the same problem. You mentioned it happens more on inclines which definitely indicates low fuel pressure/flow, the float needle in the carb is stuck, or the float level is too low. The gas lines may be clogged, bent, smashed, or if there are rubber lines between the gas tank and the electric pump (not good) they may be old and soft so they collapse under vacuum.

I would start with a new fuel filter. There may be more than one filter since the electric pump was added. Your carb has a sintered bronze gas filter built in where the fuel line screws into the carb. Most people don't know they are there so they never get changed. They are only 41 cents plus shipping: Bronze filter

 

[toneandrox]

Kevin is right and it sounds like a fuel problem. Since the previous owner removed the mechanical pump they may have had the same problem. You mentioned it happens more on inclines which definitely indicates low fuel pressure/flow, the float needle in the carb is stuck, or the float level is too low. The gas lines may be clogged, bent, smashed, or if there are rubber lines between the gas tank and the electric pump (not good) they may be old and soft so they collapse under vacuum.

I would start with a new fuel filter. There may be more than one filter since the electric pump was added. Your carb has a sintered bronze gas filter built in where the fuel line screws into the carb. Most people don't know they are there so they never get changed. They are only 41 cents plus shipping: Bronze filter

Thanks for your advice. I am in the process of trying to change the fuel filter, but a ACDelco GF157 was the filter installed and the replacement for it only includes the parts inside the filter canister but not the canister itself. We went underneath the RV trying to get the old filter canister loose but it won't come loose. We were thinking of just bypassing that filter and put in a universal filter, but there's not enough play in the existing lines and the hoses won't just fit on the universal filter. We are afraid to cut the lines at all because of the lack of hose length that exists. We were also thinking of adding an additional electric fuel pump to help push that fuel from the tank to the carb but we weren't sure if we could just add an additional pump without affecting the fuel pressure negatively.

 

[TheBar]

If you don't have one some auto parts stores like AutoZone will loan you a fuel pressure gauge. Or buy one for around $20. Before you go much further see what your fuel pressure is at the carb. Google to see what pressure you should have. Generally about 4-7 lbs of pressure. With the engine off and key on let it pump into a container and make sure you have a healthy stream. Avoid flame or sparks. Obviously. If ok then your problem must be a vapor lock or the bronze filter or internally in the carb. If not you can check the fuel pressure wherever the lines attach from the pump forward to help track down the problem. You will need to replace the fuel filter at some point so you might see if a salvage yard has the canister. Or fit a universal one.

 

[toneandrox]

If you don't have one some auto parts stores like AutoZone will loan you a fuel pressure gauge. Or buy one for around $20. Before you go much further see what your fuel pressure is at the carb. Google to see what pressure you should have. Generally about 4-7 lbs of pressure. With the engine off and key on let it pump into a container and make sure you have a healthy stream. Avoid flame or sparks. Obviously. If ok then your problem must be a vapor lock or the bronze filter or internally in the carb. If not you can check the fuel pressure wherever the lines attach from the pump forward to help track down the problem. You will need to replace the fuel filter at some point so you might see if a salvage yard has the canister. Or fit a universal one.

Thank you. I will do as instructed and provide an update in a few days.

 

[tote]

Manual or electric fuel pump?
If electric check the fuel pump relay switch.
It will be located behind the drivers side headlight.
BTDT.

 

[Ernie n Tara]

That fuel filter must be replaced, so just bite the bullet and do what is necessary to do it. Replacing part of the line if necessary!

Ernie

 

[Rene T]

Manual or electric fuel pump?
If electric check the fuel pump relay switch.
It will be located behind the drivers side headlight.
BTDT.

He said in his first post that it was changed out by the previous owner from a mechanical to electric.

 

[Skookum]

Your switch looks like some kind of isolator, shut-off, or maybe a lone-wolf starter so you can start the engine while standing at the engine instead of running inside the coach to turn it over. It looks like it's wired to the starter solenoid. If the starter solenoid is what you're tapping on to get the engine to turn over, no, that won't be the source of your fuel issue. The solenoid takes signal from the ignition (key start) and closes the contacts to provide battery power to the starter. Your switch may be wired in there to accomplish the same job...really hard to tell from the photos.

I'm with the others on the order/operations. Fuel filter should be changed out first. If that doesn't help, if the carb is original and you need to start checking needles, floats, just buy the rebuild kit and do it, if you think you can. Should come with new needles, gaskets, and maybe a float-- if not, order one separately so you can replace the old one.

This may be both a pet-peeve of mine and a safety issue...all those old leaves, pine needles you've got in your engine bay, get 'em out of there, they don't belong.

 

[toneandrox]

I have an update everyone. My husband and I put the RV in a local shop and the mechanic put in an inline fuel filter to bypass the other fuel filter that was stuck in place. He also put in a new air filter. He test drove it and told us it was fixed. We paid $200. We went to pick it up and it drove fine for about 10 miles and then stalled again. Before it wouldn't go a mile before stalling. We were able to start it right up again and drive it but it stalled again after a couple miles. The mechanic said the fuel pump may be getting hot and shutting off. My husband is hesitant about taking it back to the same guy since he charged $200 for changing 2 filters. We are going to attempt to change the fuel pump out ourselves. Since it is an older RV we are trying to get a comparable pump for it. I can't find manuals for the 1987 Coachmen Crusader (Ford Econoline E350) so I'm not sure what size the gas tank is. It is a 460 engine so I was thinking it is a 40 gallon tank but I read the original tank size for this model may have been 22 gallons. I'm just not sure.

 

[TheBar]

With shop rates as high as they are now $200 is pretty high but not completely unreasonable. To install a different kind of fuel filter likely required some fuel line plumbing changes.

Since the original fuel pump was mechanical it may not have the wiring or plumbing for an in-tank electric fuel pump. If your current electric pump is mounted externally outside the gas tank it does not matter what size the gas tank is. If it is external you need to shop for a high volume low pressure (5-7 lbs) external electric pump.

If you do have an in-tank electric pump make sure you have more than 1/4 tank of gas. They can overheat if not fully immersed in gas which keeps them cool. It would have a strainer which could be clogged on a 34 year old RV. It would need to be replaced and the mechanic should have known that. So you may not have an in-tank pump. If you don't see multiple wires going inside the tank you probably don't.

However if it drives ok for 10 miles it could very well be a vapor lock. It won't hurt or be that expensive to fix. The metal fuel lines need to be insulated or moved away from a heat source. Make sure the gas lines are not too close to the exhaust pipes or muffler. Being a van it may be difficult to see or feel the gas line around the engine. And even harder to wrap insulation around the gas line. One old fashioned fix for a tight engine compartment is to buy rubber fuel line just one size bigger than your metal lines, cut it length wise, then push the split hose down over the metal gas lines that wrap around the engine. The rubber will insulate the metal line.

 

[toneandrox]

With shop rates as high as they are now $200 is pretty high but not completely unreasonable. To install a different kind of fuel filter likely required some fuel line plumbing changes.

Since the original fuel pump was mechanical it may not have the wiring or plumbing for an in-tank electric fuel pump. If your current electric pump is mounted externally outside the gas tank it does not matter what size the gas tank is. If it is external you need to shop for a high volume low pressure (5-7 lbs) external electric pump.

If you do have an in-tank electric pump make sure you have more than 1/4 tank of gas. They can overheat if not fully immersed in gas which keeps them cool. It would have a strainer which could be clogged on a 34 year old RV. It would need to be replaced and the mechanic should have known that. So you may not have an in-tank pump. If you don't see multiple wires going inside the tank you probably don't.

However if it drives ok for 10 miles it could very well be a vapor lock. It won't hurt or be that expensive to fix. The metal fuel lines need to be insulated or moved away from a heat source. Make sure the gas lines are not too close to the exhaust pipes or muffler. Being a van it may be difficult to see or feel the gas line around the engine. And even harder to wrap insulation around the gas line. One old fashioned fix for a tight engine compartment is to buy rubber fuel line just one size bigger than your metal lines, cut it length wise, then push the split hose down over the metal gas lines that wrap around the engine. The rubber will insulate the metal line.

Thanks for your feedback. It is definitely an in-tank pump. We see the fuel lines running to the fuel pump. The previous owner had replaced the metal lines with rubber lines already. We have almost a full tank of gas in the tank so the pump should be fully immersed. We thought $200 was a little expensive because he just removed the old pump and put on the new pump without modifying the hoses. We are grateful it is running better now than before.

 

[toneandrox]

Hello Everyone. Thank you all for your valued advice. My husband and I followed your advice and we are still having an issue to report.

CURRENT PROBLEM: We can drive it a couple miles and it begins to stall until it eventually will shut off. If we rev the engine while in park, it will rev and run with absolutely no issues for as long as we desire. If we go into drive it will pull off and run fine for a few miles and then stalls.

STEPS WE'VE TAKEN:
1. Had mechanic replace fuel filter.
2. Had mechanic replace air filter.
3. Added external fuel pump to help pump fuel in case of vapor lock issue. RV starts right up each time and idles and revs up for quite a while, so we are assuming it is getting ample fuel to the carburetor. We added the external fuel pump just after the fuel filter.
4. Cleaned the fuel pump relay prongs and the housing because their was corrosion inside both. We didn't replace the relay itself, just cleaned it up so it would make a good connection.
5. We put 2 cans of Seafoam in the gas tank because we have almost a full tank of gas.

QUESTIONS WE HAVE:
1. We believe the fuel relay fuse is only 5 amps. That may have been good enough for the single in-tank fuel pump, but now that we've added the external fuel pump on the fuel line, should we add a higher amp fuse?
2. Now that we've added the external fuel pump does anything with the carburetor need to be adjusted?

 

[TheBar]

1. I would not put in a higher amp fuse or the wiring could be overloaded and could cause a fire. I doubt the size of the fuse is causing your stalling problem. Each pump really should have its own wire and fuse.

2. The carb does not need to be adjusted.

Does driving 20 mph or 60 mph make a difference? Is the engine overheating?

If you have a vapor lock adding the second pump won't cure it. Click this link: Vapor lock . When it first starts losing power and before it stalls out completely pull over and let it idle for a few minutes giving things time to cool off. Or will it die even while idling?

You still could have some kind of fuel line restriction. It requires more gas when driving than when sitting still in the driveway. Which would explain why it runs fine in the driveway.

Did you check the fuel pressure and flow? Did you check the sintered bronze gas filter inside where the gas line screws into the carb? Since you have an in-tank fuel pump there is a "sock" filter over it that could be plugged up. In most cases that requires dropping the gas tank to get to it.

 

[toneandrox]

1. I would not put in a higher amp fuse or the wiring could be overloaded and could cause a fire. I doubt the size of the fuse is causing your stalling problem. Each pump really should have its own wire and fuse.

2. The carb does not need to be adjusted.

Does driving 20 mph or 60 mph make a difference? Is the engine overheating?

If you have a vapor lock adding the second pump won't cure it. Click this link: Vapor lock . When it first starts losing power and before it stalls out completely pull over and let it idle for a few minutes giving things time to cool off. Or will it die even while idling?

You still could have some kind of fuel line restriction. It requires more gas when driving than when sitting still in the driveway. Which would explain why it runs fine in the driveway.

Did you check the fuel pressure and flow? Did you check the sintered bronze gas filter inside where the gas line screws into the carb? Since you have an in-tank fuel pump there is a "sock" filter over it that could be plugged up. In most cases that requires dropping the gas tank to get to it.

Thanks for your reply.

1. It never over heats. It will stall as though it's running out of gas. If we pull over before it dies and put it in park it will idle no problem.

2. The pressure was fine according to the mechanic we took it to.

3. We were planning to look for the the filter near the carb today. The mechanic changed the air filter but never mentioned the little gold filter going to the carb.

4. We were told by a neighbor to check the ignition control module. We are planning to have that tested and possibly replaced today.

5. Last if all fails we will drop the tank to check sock filter.

Thanks so much

 

[John From Detroit]

STEPS WE'VE TAKEN:
1. Had mechanic replace fuel filter.
2. Had mechanic replace air filter.

Well... I was going to make a suggestion but I see it's not necessary you already did it.

On a related subject.. I used to have a car that ran good at idle but at speed. VERY rough. like it was fuel starved.. new filter did nto help.
New fuel lines did seems they had got religion (Become Holey) and the pump was sucking air.

 

[SeilerBird]

My last class A had two fuel pumps. One was located inside the fuel tank.

 

[toneandrox]

Well... I was going to make a suggestion but I see it's not necessary you already did it.

On a related subject.. I used to have a car that ran good at idle but at speed. VERY rough. like it was fuel starved.. new filter did nto help.
New fuel lines did seems they had got religion (Become Holey) and the pump was sucking air.

It appears the last owner already replaced the fuel lines and switched from metal to rubber lines and they are all in good shape.

Thanks