94 Winnie Brave F53 7.5 Engine/Smoke Issues

[White Swan]

Good Day good folk,

Though a long time RV owner I'm new here but have perused the site before and read many informative posts past and present.
May I start by adding I've been an avid mechanic owning a slew of cars since I started driving in back in the early 60's and have always been relentless in keeping the vehicles maintained and running properly.

I've owned my 94 Brave for over 25 years now and have meticulously maintained her mostly by myself with the exception of some larger jobs like a fuel pump once by the dealer here (Mid Ten Ford) that will no longer even look at the coach as it's over 20 year old. No one but me now)

I recently rebuilt the EEC lV electronics (with new caps), solved a belt alignment issue after a new water pump and alternator and recharged the AC. Also did an E4OD fluid/filter change & replaced the MLPS as I was having serious shifting issues, that solved that issue.

Everything was running like a top (or so I thought) as I had taken her out up and down serious grade hills and some 20 mile cruises, I'd just done an Obd-1 scan and got a 111 pass and 10 scan code, happy chap. Last week took her out again cruising beautifully and returned, backed into the RV port and shut down.
Ten Minutes later I tried to start up again only to have an extremely rough running engine blowing black smoke and dying on idle. Scanned again and got 13 codes, what in the world just happened I asked. Took out all the plugs, all completely fouled & smelling of gas. I know Im in an over rich state but why and whats doing it. Absolutely gutted and dumbfounded!!!!!

Did some Irv2 research and replaced the fuel pressure regulator (Standard Motor Prod. PR15) Checked every connection (Disconnect Re-connect) particularly the MAP, checked vacuum to new regulator and searched for leaks. All seems good. I know I have good vacuum as I can hear the EGR valve dissipating the reserve from the system canister up front on shut down.

Waiting on a new Motorcraft MAP sensor today, cleaned all the plugs with a torch and reinstalled as they look just fine for now. I also have new plugs but didn't install as yet as I didn't want to foul them immediately on a start with a failed repair. I will try the MAP when it arrives and advise.

If the MAP fails I'll once again be at the "Throwing Parts at it" stage.
Might I ask if any of you might have another suggestion should the MAP sensor fail to remedy my situation. I'm just stuck as it is.

I greatly appreciate your time and advice.

White Swan

[MSHappyCampers]

Hi ! Welcome to IRV2! We’re sure glad you joined the gang here!

Hopefully someone will be along that can help.

Good luck, happy trails, and God bless!

[HarryStone]

Does your rig have a MAF as well as a MAP?

[nvs4602]

I'm a big fan of seafoam.
https://shop.advanceautoparts.com/p/...B&gclsrc=aw.ds

Have a truck that only gets driven about 5k miles a year. I use it as a stabilizer and to keep the fuel system clean.

They sell this kit at many automotive stores, but I've found Wal-Mart usually has it cheaper Use the spay can as directed spraying it directly into the intake and add the second can to gas tank at a rate of at least 1 ounce per gallon.

This has also worked good for me in small engines were the carb was gummed up because I forgot to drain the bowl before storage. I had to run it on full choke to keep it running. Once I mixed up some seafoam and gas at 4 ounces per gallon and started running that through. About 45 min I of slowly opening the choke it ran fine with the choke open as it should..

It's worth a try and definitely won't hurt anything.

[twinboat]

Did you shine a timing light on the marks.
May have jumped time.

Pull the distributer cap and bar the crank back and forth while watching the rotor play.

[White Swan]

I do have a timing light, unfortunately I don’t have anyone to help with cranking, not quite sure exactly the procedure. May I ask you to explain further. The big issue is the fact that the coach was running with jet like performance before it went down simply by turning it off pretty much the same as it always has. I’m baffled actually.

[White Swan]

Originally Posted by HarryStone

Does your rig have a MAF as well as a MAP?

I believe that the 94 version of the Ford 7.5l only has a MAP. I recall reading this in a truck forum as I’d searched high and low for a MAF on my engine. The only thing I found on or close to the two air intake tubes at the manifold was the throttle position sensor. I could be wrong of course. There definitely isn’t anything like a MAF on or near the air cleaner, that was the first place I looked.

[donr103]

Did you check fuel pressure ? That would be 1st for me imho .. next cap and rotor.. cheapest and fastest.. if you don't have fuel pressure test gauge.. most good auto parts store and they will rent you one for free..
Good luck and keep us posted

[White Swan]

Originally Posted by donr103

Did you check fuel pressure ? That would be 1st for me imho .. next cap and rotor.. cheapest and fastest.. if you don't have fuel pressure test gauge.. most good auto parts store and they will rent you one for free..
Good luck and keep us posted

I did check the cap and rotor both look good and I cleaned the contacts of some residue whilst in it. Is it possible to get a good fuel pressure reading with just ignition on and fuel pump engaged, I can hear it spinning up and I’ve also changed the filter. I can get a gauge and know where the Schrader fuel valve is for the connection to gauge.

[donr103]

Yes.. you can get fuel pressure reading with out starting engine with key on.. I would start there.. just because you hear it.. does not mean you are getting correct pressure.. and so easy .. but why do you not want to try and start it.. and read fuel pressure too? Imho do both.. if you get a gauge on it.. I am not saying this is your problem.. just where I would start there.. . Also pull fuel pump relay and replace it.. check relay terminals for burning or melting.. cost less than 15 bucks.. when ever I pull very old relay.. I just replace it with new one..
Good luck and keep us posted

[twinboat]

Originally Posted by White Swan

I do have a timing light, unfortunately I don’t have anyone to help with cranking, not quite sure exactly the procedure. May I ask you to explain further. The big issue is the fact that the coach was running with jet like performance before it went down simply by turning it off pretty much the same as it always has. I’m baffled actually.

I had a smooth running engine that jumped a loose timing chain when I shut it off.
How many miles on your engine ?

If you watch the rotor as you turn the engine back and forth with a socket on the crankshaft bolt, you can see if there is play in the chain.

With a timing light, hook it to any spark plug wire and make a few white marks anywhere on any pully.
With the engine running, the light should show the mark in the same spot.
If the mark is jumping around, that's a clue of a bad chain.

[White Swan]

Originally Posted by donr103

Yes.. you can get fuel pressure reading with out starting engine with key on.. I would start there.. just because you hear it.. does not mean you are getting correct pressure.. and so easy .. but why do you not want to try and start it.. and read fuel pressure too? Imho do both.. if you get a gauge on it.. I am not saying this is your problem.. just where I would start there.. . Also pull fuel pump relay and replace it.. check relay terminals for burning or melting.. cost less than 15 bucks.. when ever I pull very old relay.. I just replace it with new one..
Good luck and keep us posted

Yes I replaced the relay with a new one and was careful to check it’s imprinted circuit making sure they were identical. The new one made no difference I’m afraid. I didn’t see any corrosion on the originals (which I don’t think is bad now) terminals nor inside the socket itself. Boy I sure hate to deal with the fuel pump again, my only option would be to use straps from the roof to lower it where the coach is resting under my RV Port. I have thought about that as something I could probably accomplish alone.
You folks are really great by the way, very kind of you all to take this time to advise.)

[White Swan]

Originally Posted by twinboat

I had a smooth running engine that jumped a loose timing chain when I shut it off.
How many miles on your engine ?

If you watch the rotor as you turn the engine back and forth with a socket on the crankshaft bolt, you can see if there is play in the chain.

With a timing light, hook it to any spark plug wire and make a few white marks anywhere on any pully.
With the engine running, the light should show the mark in the same spot.
If the mark is jumping around, that's a clue of a bad chain.

I’ll give that a try when I can get another hand to help me crack from below, can’t do it from inside the doghouse.
Someone asked how many miles on the vehicle, it has just over 33,000 original miles.
Used it almost every weekend after acquired and visited my folks in FL several times. Has not been used much over the past decade but exercised regularly over other week.

[MarvinG]

I don’t think you are going to need to pull your fuel pump. Sounds like you have too much fuel not too little (IF it is fuel pressure problem). I agree the first place is to check the fuel pressure. I borrowed from Autozone but finally I just bought a fuel pump gauge. The one I purchased was only $30 and I keep it on my RV along with my code scanner when I travel. Gives me some peace of mine knowing that if I do have trouble, I can at least get an idea of what is going on.