Community Forums

Phrog · 07-07-2018, 02:33 PM

I have a 1996 holiday rambler with a ford v-8 engine. Twice now the vehicle has stalled out on the road when the outside temps were in the high 80's. Engine water and oil temps remained in the normal range. Engine itself did not seem to be overheated. Situation starts to appear after about 1.5 hours on the road. initial issue is gradual loss of power, especially on inclines. Then power loss increases and an inability to increase speed. Engine does not respond to attempts to accelerate. Occasional backfire; check engine light; and a "growling" noise similar to going downhill in low gear. Eventually, the vehicle stalls.

Engine seems to return to normal within a few hours (engine will start and operate normally). Since I was close to home both times this happened, I don't know if the problem would show up again if I drove for a prolonged time.

Anyone had this issue with a ford v-8? A friend suspects that the ICM and/or ECM overheats causing erroneous signals to be sent to the engine.

Any thoughts would be appreciated. Going to dealer next Monday, but they offer little hope unless the RV evinces the problem when I bring it in.

IggyTech · 07-07-2018, 03:18 PM

Is your engine a 460cu in?
Here is a thread from someone that had a old rig with a 460ci in.

http://www.irv2.com/forums/f23/engin...ays-86652.html

Have you replaced your fuel filter in the past 20 years?
Sound like it may be a partially clogged filter.

It may be a weak fuel pump

The next thing would be vapor lock.
If it happens again and you are off the road go and open the gas cap to see if it has a lot of pressure sound when you open it. If you do its vapor lock.

Their is other electronics that may cause that especially in a rig your age.
This is the best advise I can give here.

Phrog · 07-07-2018, 04:47 PM

Not sure off hand what the displacement is on the rig.

Fuel filter was changed last year.

Will check other issues mentioned.

Thanks

subford · 07-08-2018, 05:45 AM

Sounds like loss of fuel pressure.
Most likely a bad fuel pump.
The backfire is from an lean fuel mixture.
The engine light better known as the MIL says you have stored codes in the the memory of the PCM. But more than likely it would be an O2 code from the lean fuel mix.

Is this a Class "A" RV?
If so the Black ICM mounted in front of the radiator very seldom causes problems.
The ECM better known as the PCM is mounted inside the passenger compartment and not likely to cause this problem.

Yes he has a 460 (7.5L) engine with an E4OD transmission.
The fuel pump is cooled from the fuel in the tank so when the fuel level gets low it can cause the fuel pump to over heat. So if you keep the fuel level around one half tank or above it may not cause the problem.

Phrog · 07-08-2018, 08:37 AM

Yes, I have a class A rig. I've seen the ICM mounted on the firewall on the driver's side of the RV.

Fuel pump may be the problem as the issue has occurred on the return side of both trips when the gas tank was somewhere near half or slightly below. Since the problem happened within 10 miles of my destination, I guess once the engine restarted, I didn't see a recurrence of the problem over the short distance home.

Phrog · 09-05-2018, 01:57 PM

So, an update to my originally posted power loss/stalling issue on my Holiday Rambler. I tried the "full fuel tank" solution on my last 2 trips. Each leg is about 160 miles one way. In July I left home on a full tank and drove about 120 miles before stopping. No issues on this leg. Temps initially were in the mid 70's. The last 40 miles were in the 80's, but still no problem. A week later I did the return trip with a full tank with ambient temps in the mid 70's again & no problems. About a month later I did the outbound leg again non-stop. This time the temps were in the low to mid 80's. The trip was again uneventful until the last 5-6 miles when I began to experience a lack of acceleration above 40-45 mph (from a 35 mph speed zone). I was finally able to get up to about 50 or so mph just before reaching destination. Just prior to this occurring, I was going through an area of stop & go traffic and slow speeds. No stalls or warning lights, although I did detect the odor of burning rubber, and my brakes became very mushy. On the return trip a week later I again drove straight thru in mid 70 temps with no issues. On all legs, I used less than a third of the gas, so I'm beginning to think the fuel pump may not be the issue causing the engine problems in high ambient temps. I'm at a loss. A few folks have suggested the Ignition control module as the culprit. Again, I have no idea.

okcnewbie · 09-05-2018, 02:08 PM

I have the same or similar problem with my 1996 Tioga with the Ford.

My problem seems to only happen with temps in the mid 90's or higher. Even then it might only happen when the AC is on. I've driven 8hrs with no problem at all with temps in the 80's.
Last weekend I tried to make it home about 200 miles with temps in the 90's. After about 1 hour I stalled and had to wait for the sun to go down. (about 2 hours) The temp was still 90 but I left the AC off and made the rest of the trip no problem.
When this happens the engine is hot but not overheating. I'm going to hook up a fuel gauge that I can tape to the windshield. It acts like a vapor lock but I know that's not likely with FI.
I have almost 50k mileage.

Phrog · 09-05-2018, 02:35 PM

My engine temp gauge stays within a couple of degrees right and left of the center position. It has never gone into the hot zone, nor has the engine hot light illuminated. My A/C is disconnected, so that isn't an issue for me. If I need A/C, I fire up the generator and turn on the coach A/C.

I guess the issue is workable as long as you stay on highways with ample space to pull of the road and wait an hour or two for things to cool down. However, that isn't always the issue and I dread the thought of stalling out on a two lane road with no place to pull over! For that reason alone, I want to find a solution.

1bigmess · 09-05-2018, 02:39 PM

Quote:

Originally Posted by IggyTech

Have you replaced your fuel filter in the past 20 years?
Sound like it may be a partially clogged filter.

It may be a weak fuel pump

The next thing would be vapor lock.
If it happens again and you are off the road go and open the gas cap to see if it has a lot of pressure sound when you open it. If you do its vapor lock.

Start with the basics: fuel, air, spark.

The quoted info above is good advice.

CountryB · 09-05-2018, 02:49 PM

Replace the Ignition Module - its cheap and easy to do. There is a good chance that is the issue (especially if you have the one that is mounted to the distributor base (these where eventually moved to a remote mount due to heat problems).
Even if the problem remain, at least you removed one component form the "list of possible things".
https://www.rockauto.com/en/catalog/...ule+(icm),7172

jarwiebe · 09-05-2018, 03:01 PM

Is there any correlation between the smell of burning rubber and mushy brakes with the "feel" of loss of power, could you have a brake that's is not releasing?

okcnewbie · 09-05-2018, 03:16 PM

Quote:

Originally Posted by CountryB

Replace the Ignition Module - its cheap and easy to do. There is a good chance that is the issue (especially if you have the one that is mounted to the distributor base (these where eventually moved to a remote mount due to heat problems).
Even if the problem remain, at least you removed one component form the "list of possible things".
https://www.rockauto.com/en/catalog/...ule+(icm),7172

Thanks Mike. I think I will do this.

Phrog · 09-05-2018, 05:19 PM

OK.

1. Fuel filter was replaced when I first bought the RV and again last summer.

2. Tried the fuel pump "fix". May still be a contributing factor, but still not completely convinced.

3. Haven't had the issue recur to the extent I had to pull over, but will check gas cap if that happens again.

4. The Ignition module is on my list because it is cheap to replace.

5. Brake issue happened once before a couple of years ago. As did the smell of rubber. Had disappeared until just a couple of weeks ago. Doesn't appear to have been an issue in the "feel" of power loss. Brakes are going to be bled this fall anyway.

subford · 09-05-2018, 06:14 PM

Sounds like both of you have a PIP sensor problem.
On the class "A" the ICM (Ignition Control Module) should not be effected by the higher temp as it is in front of the engine compartment. But if you do change it out make sure you buy one that is Black in color as the gray one is the wrong one and will cut down on power and through a code.
Do not through the Black ICM away as most replacements are not as good as the original and as I have said above it is very rare for a Black remote mounted ICM to be bad.

By the way I did not see where either of you posted the codes. You will have a code in the CM part of the self-test after the KOEO read out is done.

On the class "C" if you have fuel pressure (32-40psi) when this happens then I would think it to be the PIP sensor.