F53/460 computer scan

[popeye766]

I have a bad jerking miss in my Class A.....Iam going to take it to a dealership for a diagnostic check.....has anyone had this done....if so how long and what were you charged......Iam in ARK.

[spcorvette]

The TFI should be located on a Aluminum heat sink on the radiator support. Other than the PCM, there is noting else in the ignition system.
If it misses all the time, an easy way to check ignition function is to put a timing light on the Coil wire an see if there is any interruption in the light when it misses. If there is, it is the TFI or Hall sensor (Pickup coil).

If it is not ignition, one other thing I have seen is a corroded wire at the connection between the Injector harness and the Main engine harness.

Keep us posted.
Terry

[popeye766]

Thanks terry...96 pace arrow 33' 460. OBD 1

[spcorvette]

Sounds like ignition. Possibly the pickup coil in the distributor. If one of the wires in internally damaged, it will cut off when the distributor advances.
Have you replaced the TFI module?
A bad TFI would have all the symptoms your are having. It will usually be worse after the engine is warmed up.

Other than the PCM, there is no other hardware in the Ignition system.

What year is your coach?
Terry

[fcooper]

popeye766 wrote:
however realized a weird thing....I have a 110 plug in a over our head compartment to plug in a device I guess. I had my Direct TV receiver plugged in it...during testing when I turned my key switch on IT turned that 110 plug off....WTH ? .

It's a safety feature to keep the TV from working while the vehicle is running. Perfectly normal.

Wish I knew what your other problem was, however.

Fred

[popeye766]

Had much to do today and even tho I removed the doghouse and hooked up my scanner IT wouldn't communicate..tried and tried no help...however realized a weird thing....I have a 110 plug in a over our head compartment to plug in a device I guess. I had my Direct TV receiver plugged in it...during testing when I turned my key switch on IT turned that 110 plug off....WTH ? I didn't get to continue because we had company and all that so I just quit for today. If its a fuel issue Iam going to strive to install an add on outside pump. interested IN OTHERS analysis....and thanks...

[MountainAir05]

You can check the plug wires and coil with a timing light.

[Daveinet]

I would lean toward a weak fuel pump. If it was just a filter, it would run perfectly fine at idle. If the fuel pump is not able to maintain pressure, it will make it run a little on the lean side all the time, as well as run out of fuel under harder acceleration. While it could be just random electrical, the fact that it runs much worse under acceleration seems much more like it is running out of fuel. I'm not an expert on Ford TBI, but as I understand it, it is extremely primitive, and does not really run closed loop. This means it will not know it is running lean and compensate like a GM will. (later Ford is much, much better)

[Gale_Hawkins]

How much is a new coil?

Read all of this especially the 2013 post.

specific miss on 2 and 8 after tune up.

Hope you find something before it is time to hit the road.

Since it was running fine for 200 miles something has changed for sure as we all know. You are leaning spark and not fuel to be the problem and I tend to do the same. However when going from good running to poor running you have to start all over again.

Fuel pump pressures and new compression test would rule out a lot of things. The capacitors mentioned in one post could be the issue if it is electrical in nature. At this point we have to assume the problem could be about anything. The more you rule out the better.

If you are getting spark, fuel at the right time and place and have fair compression you should run we all know.

Keep us posted.

[popeye766]

Gale...yes on Onan running all the time...of course I couldn't tell anything until it quits.....so no help there..all my batteries are WM ....Its like the coil is shorting or someone is turning the ign. sw on and off....and when you are pulling with a truck behind its a violent miss...

[Gale_Hawkins]

I had a crazy running 1988 BMW that was fine after I replaced the battery the second time. Yes it did not run right with the old battery or the first new one but did with the second new one and both were from WM.

I have three 12v battery under the nose and can just rob a house battery in a couple minutes by changing battery connections. Not sure about your set up. If our key is on the chassis and both house batteries are in parallel so when our alternator was out I kept the house battery next to the starting battery disconnected so if we lost the generator we could get off the road if the other two batteries died or shorted out.

Have you had the house generator running any while it was missing? Do you get any back firing?

[popeye766]

Thanks Nick..I have one and will plug it in in the AM. Iam even wondering about a shorted battery..

[Nick-B]

Popeye,

You should be able to buy the Equus 3145 Ford EEC-IV scanner for under $40 at a local parts store. That scanner is easy to read and the book with it gives good instructions. The dealer will charge you more than $40 just to pull in the lot.
Best of luck!

[popeye766]

GALE/FRED..the missing is violent and worse under full power demands...but always there...at my 2nd fill up no 89 octane so I put in 13 gal 87 and 30 gal 93.....I figured hardly anyone buys ethal so I got water in it....In my station I checked the tanks for water every day but most don't. anyway,Iam in COE park in ARK and plan to be here 6 weeks so Iam not desperate yet...But I still have to get this 11 tons 650 miles home. Starts easy, low speed Ok.......Its like a broken wire somewhere that's striking contact...now and then. Motor is solid ,having a valve job 5,000 miles ago. Burns no oil, 150 PSI in every cylinder....strong and solid ...I'll investigate in the AM. and BTW....there is no check engine light with such a bad miss....that's why if I don't get any codes with my scanner in the AM Iam going to take it to Ford. What the H does it take to throw a light??????

[Golden_HVAC]

What I did with my 97 F-53 with 460 engine is replace the O2 sensor and the cap and rotor to pass the smog check a couple of years ago. I guess you replaced that and more.

How has it been running since you added the sea foam?

Are you buying the lowest possible cost gasoline? I have found problems with Costco gas, so I have been buying Chevron 91 octane since that time, my last trip I took it slow because I was un-employed, and needed to save gas. At 55 MPH, towing my Manx dune buggy, I was getting as much as 8.8 MPG. Best ever! Normally I would get 7 MPG while towing a slightly heavier car, and doing 65 or so.

So try it - 91 octane. The engine controls can advance the timing, tell there is no pinging, and you can make more horsepower per gallon of gas. I find the cost is slighly more than 4% more, yet the MPG improvement has been 10% or more.

Fred.