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Annadams · 04-09-2015, 12:34 PM

I have a 1996 Thor Residency motorhome gas 460 Ford engine. When the outside air temperature gets above 60 degrees the motor home will stall when coming to a stop. Takes about an hour and a half for it to cool off enough for it to be driven again. All guages are normal. None of the 5 mechanics that have worked on it can solve the problem. Does anyone have any ideas???

**JohnRR** · 04-09-2015, 01:22 PM

Good luck with a solution.

MSHappyCampers · 04-09-2015, 01:56 PM

Welcome to IRV2! We're sure glad you joined us!

Sorry I can't help with your problem! Enjoy the forum!

Good luck, happy trails, and God bless!

subford · 04-09-2015, 01:57 PM

Quote:

Originally Posted by Annadams

I have a 1996 Thor Residency motorhome gas 460 Ford engine. When the outside air temperature gets above 60 degrees the motor home will stall when coming to a stop. Takes about an hour and a half for it to cool off enough for it to be driven again. All guages are normal. None of the 5 mechanics that have worked on it can solve the problem. Does anyone have any ideas???

Bad PIP sensor. Replace the stator in the distributor.
Run a scan of the CM codes and if the battery has not been disconnected the CM codes will show if this is the problem.

If not that then one would think you have a bad fuel pump.
To check this put a fuel pressure gauge on the fuel rail and drive it until the problem happens. Dose the fuel pressure drop below 30psi when the problem happens? If so replace the fuel pump.

MT4Runner · 04-09-2015, 03:12 PM

Quote:

Originally Posted by subford

Bad PIP sensor. Replace the stator in the distributor.
Run a scan of the CM codes and if the battery has not been disconnected the CM codes will show if this is the problem.

Should one of 5 mechanics have checked codes?!

Quote:

If not that then one would think you have a bad fuel pump.
To check this put a fuel pressure gauge on the fuel rail and drive it until the problem happens. Dose the fuel pressure drop below 30psi when the problem happens? If so replace the fuel pump.

Then again, one of 5 should have checked fuel pressure, as well!!!

subford · 04-09-2015, 04:08 PM

Quote:

Originally Posted by MT4Runner

Should one of 5 mechanics have checked codes?!
Then again, one of 5 should have checked fuel pressure, as well!!!

Most do not even know where to plug the code reader in on a 460 F53.
The same goes for the fuel pressure check but not as likely as the code reader plug.

Reniram · 04-09-2015, 07:06 PM

It for sure needs to be systematically checked out, it all too easy to say ,,could be this or could be that...that being said my next door neighbor had the same symptom which turned out to be a plugged catylitic converter...

Medico · 04-09-2015, 07:22 PM

Welcome, glad to meet you!

subford · 04-10-2015, 06:10 AM

Quote:

Originally Posted by Reniram

It for sure needs to be systematically checked out, it all too easy to say ,,could be this or could be that...that being said my next door neighbor had the same symptom which turned out to be a plugged catylitic converter...

FYI he does not have a catalytic converter.

muscob · 04-10-2015, 07:10 AM

Do you have a distributor? If you do, have your ignition module check.

subford · 04-10-2015, 08:06 AM

Quote:

Originally Posted by muscob

Do you have a distributor? If you do, have your ignition module check.

He has a distributor but he also has the Black remote mounted ignition module (ICM) and the Black remote mounted ignition module very seldom if ever goes bad.
But a lot get changed and replaced by the wrong Gray one.

zmotorsports · 04-10-2015, 08:49 AM

I have run across this many times in the past but not so much over the most recent years as I think most of these older 460's have already been addressed but it sounds like a fuel pump/vapor lock issue.

It was quite common and would not throw codes even on an OBDII system. Many people would say they would run fine and stall coming off the interstate to stop sign and it had to cool off before re-starting. I was wiht a friend traveling through eastern WY many years ago when his 1991 Ford Class A started acting up and I ended up replacing the fuel pump for him in Sheridan, WY before heading home. I have replace about a dozen of these for people over the years and Ford has had mutliple revisions of this pump and the TSB that goes along with it.

I haven't done one in the past two to three years but the most recent part and TSB numbers I have in my records are as follows in this excerpt from a thread I posted in a couple of years ago:

Ford's TSB # 97-23-9. The latest version pump is a F6PZ-9H307-BB. The one ending with DB such as the one you said they sold you is the older revised version. The pump @ $585.00 is not a bad deal as that is not much over what dealer cost is.

I will not use an aftermarked fuel pump in this particular application due to the nature of the issues Ford has had with this pump. I will ONLY use a Ford OEM (updated) fuel pump. I will also NOT install a pump (or any parts for that matter) that the client brings to me and tells me to install on their vehicle. The reason being is that some people are not honest and bring inferior parts and want the technician/shop to install them and then stand behind them. If I install a quality part that I purchase from my normal local parts supplier and if I have a problem with the part it is not the responsibility of the client to pay to have those parts exchanged but I can file a labor claim with the company I purchased the parts from and they will process it without question. This way I can at least re-coup some labor for replacing the faulty part. I cannot do this with a part the customer brings me. I must also note that in all my years of wrenching I have not had many issues with new parts being faulty, this is due to being up to date on parts and using high quality parts to begin with.

I hope that may shed some light on the situation and at least give you some starting point to share with the shop you take the coach to. Upon first diagnosing these I found no codes displayed through the ECM, I found fuel pressures to be within specification and the only thing that was suspicious was a volume test but this must be done while the condition exists and everything is hot. NOT fun.

Although an ignition system failure can act similar so I would rule that out first as many of those components you can check with the exception of the ignition module or the TFIM as Ford calls it. After checking the ignition system I would move on the following the TSB listed above.

Hope that helps.

Mike.

Annadams · 04-11-2015, 06:29 AM

Thanks to everyone for your insight. Yes, they did check codes, nothing showed up. The fuel pump pressure test checked out good.
Installed a new fuel filter, complete tune up with plugs ,wires, rotor, distributor cap ,EGR valve, ignition module, coil. Will take this information to our mechanic. great suggestions. Mike. does the engine have to be run up to temperature or can it be idled to temp to test the fuel pump volume? Thanks again.

zmotorsports · 04-14-2015, 10:30 AM

Quote:

Originally Posted by Annadams

Thanks to everyone for your insight. Yes, they did check codes, nothing showed up. The fuel pump pressure test checked out good.
Installed a new fuel filter, complete tune up with plugs ,wires, rotor, distributor cap ,EGR valve, ignition module, coil. Will take this information to our mechanic. great suggestions. Mike. does the engine have to be run up to temperature or can it be idled to temp to test the fuel pump volume? Thanks again.

In order to test the volume you need to simulate the conditions so yes it does need to be hot. This is where the problem comes in because first off, I hate working on a hot engine and secondly (more importantly) I hate having fuel or fuel vapors around a hot engine.

I had done so many over the years that I can almost tell by the way it runs when acting up and once I check out the ignition system and it appears to be in proper repair the fuel pump TSB is the next item in the sequence which cures the issues.

I'm not goint to lie, it is a PITA job.

Namely because by the time they come to me the owners figured they would just fill the tank and all would be good. Now the tank has to be dropped and fuel pump replaced with a full 80+ gallons of fuel. NOT fun.

Mike.