Apologies in advance for the novel but I've been banging my head up against this all day and I need some advice or ideas.

I bought this 1989 28 foot class A mothorhome this year. It's an Airex by Rexhall. It has a 460 out of an E350.

I took it to Jackson WY in May, it ran fine although I have to watch for overheating on long hills and it burns oil.

I went out today and fired it up and it started. I ran it for 5 minutes and then attempted to back out of my driveway. I got halfway out and it started to struggle the motor seemed like it was missing or perhaps fuel starved. Eventually it died and I could not get it to start again.

I went ahead and replaced the plugs, wires (keeping the wires in the same order they were in before), cap and rotor, and ran it with some seafoam dripping in via vacuum line, and it did run but it was sluggish and seemed to still be missing.

I looked up a diagram just in case i messed up the distributor order, and this is where it gets strange - The number 4 cylinder (passenger rear) was plugged into the number 1 spot on the distributor cap. I know I did not mess that up when changing the wires, as I pulled the boot off I thought to myself "hmm i always thought the furthest forward cylinder was number 1". But keep in mind it ran this way, I drove it several hundred miles back in May this way. It only now started to run poorly.

I figured the incorrect order was the cuprit so I changed it up and did it correct according to the diagram. But now it just cranks, it doesn't even act like it's trying to start up. No chugging, no change in the rpms at all, it just cranks as if there is no fuel at all or no spark.

I pulled the boot off a couple plugs and they do have spark when cranking. I triple checked the order and it's correct. So I figured it's fuel. THere is pressure when I depress the valve on the fuel rail although a bit of air hisses through before the fuel does.

I have a couple ideas. Maybe the incorrect order for the plug wires was done on purpose and there's a reason for it. If so, why might this be? And how can I tell what the order should be if it's not the standard?

My other idea is maybe it has a low pressure fuel pump in the tank and a high pressure pump further up, like is normal for pickups in this year range. I hear a pump spin up when I turn the key on. Maybe the low pressure pump is bad, so the high pressure pump provides pressure but no fuel? Hence the hissing of air out the valve? Or maybe there is a leak in the line between the two? I don't actually know if the motorhome has a low and high pump, i'm just guessing.

 

In an 1989 F53 you do not have a HP pump on the frame, just the one pump in the fuel tank.
Is your ICM (TFI) mounted on the distributor or is it remote mounted in front of the radiator?
I was think it is remote mounted.



/

 

Don't count on the cap Number 1 position being correct. someone may have changed it. Put engine number one cylinder on compression stroke at top of stroke. pull cap and see where rotor is pointing. Use that as number one. also make sure rotor is turning when cranking. Timing chain could have let go, or jumped time.

 

I recommend getting a fuel pressure to plug in and see what kind of pressure if any is there, it's worth the $ 20 or so to have around for times like these .... then you can move on without as much guess work.

 

I'm not sure where the ICM is, I'll be working on it some more today so I'll locate it and find out. Once I find it what should I do with it?

 

This is great advice, I would never have thought this could be changed. I did learn that a local shop put in a used 460 back in 2012, so maybe it is different. My dad has a fiber optic camera, I'm gonna do as you said and set number one to top dead center and see where the rotor is pointing.

Just to make sure, the starting position of the number 1 cylinder may be different, but the firing order after that will be the same? 15426378 counter-clockwise? I can't imagine a way to change the firing order but I figured I'd check.

I'm pretty bummed that a shop put in a motor not too many years ago and it already overheats and burns oil...

 

Good advice for sure. No sense guessing especially if it means dropping the tank.

 

After working on this for many hours today I've solved both problems. I used a fiber optic camera and set the number 1 cylinder to top dead center and the rotor was pointing two positions clockwise (90 degrees) from the number one wire position.

So I shifted every wire two positions clockwise, and now I can get the motor to run again when I give it fuel through a vacuum line.

Next I checked the fuel pressure and it was spurting out a minute bit of fuel but not even one PSI on the pressure gauge. The high pressure pump was running, and I could hear the low pressure pump running when i put my ear to the filler neck. I checked all the lines between each and didn't see any breaks or issues.

So, I bit the bullet and dropped the tank. As soon as I pulled the sending unit out I found the issue. The rubber tube between the metal fuel line and the pump was disconnected. And, the rubber itself was soft and melty-feeling.

So I'll order in another pump. The pump is probably working, but since i've got it out I may as well replace it. Once I have a connection between the pump and the line again, I imagine I'll be back in business.

 

You said it was a 1989 class "A" Motorhome on an F53 chassis with a 460 & E4OD.
But You are describing the fuel system of a 1989 class "C" Motorhome on an E350 chassis with a 460 and maybe a C6 transmission.

Can you clarify what the Motorhome was you were working on for future reference maybe with the VIN minus the last 4 digits?

 

It's a class A with a Ford 460 out of an econoline 350. I have no idea what transmission it has. It has a two fuel pump system and after cross referencing the model of the low pressure in tank pump, it evidently comes from the Ford 5.0 motor.

I appreciate your interest in helping out and with the suggestions of the folks here I've already solved the distributor issue and as soon as the new fuel pump arrives and I reinstall the tank I'll have that issue solved as well.

thanks again

 

Glad to hear you're solving some issues, I have a Class C 460 based that I need to get to soon perhaps a similar issue that I suspect fuel pump. Interesting tid bit on that fuel pump hose deteriorating and coming apart ....

 

It is not uncommon for the hose to do that on mid to late 80's Ford trucks. It is caused by the alcohol in the fuel.

Here is a photo from my 1986 Bronco 2 showing the hose dissolved:


/