Need a Mechanical assist

[Ron Mc]

My youngest son has a 91 F150 XLT lariat. Straight 6 with EFI.
We seem to be having a "miss" problem of sorts. When I push on the gas there is a hesitation or choking feeling in the acceleration.
It's been in the garage for 2 days now and they have called to let me know that they have checked timing, plugs, wires, distributor cap, fuel pump, fuel filter, points, and whatever else you can think of. Yet they can't figure out what is wrong. So I basically got two days of work for free but the truck is still not fixed!
They think it has something to do with the fuel system.
My son will be able to drive alone in 3 months and I'd really like to have this thing running good before I hand him the keys. Anyone have any ideas?

 

[Nolan]

The Fords used to have a driveability problem with the ignition modual. Had to do with the dielectric material they used if memory serves me right. When they started to fail they would stumble and sometimes even stop running but start back up again. Unlike Chevys that die completely (usually just dont start one day). This is a suggestion that asumes that all other areas have REALLY been properly tested and eliminated. I dont know if this will help so take it with a grain of salt. I have had them present this way more than once. Used to own my own shop and had a client that ran Ford vehicles for bus service to airport.
Nolan

 

[alamocdc]

Ron, the first thing I thought of hasn't been addressed by the garage (and that surprises me). It sounds like it might be clogged or gunky fuel injectors. I know there are many treatments and cleaners out there, but I still use my old trusty. Back when I had a garage and rebuilt carbs (yes, pre-injection days), Berryman's Carb dip was the only one I used. You can find Berryman's B-12 in any good automotive store. Pour a can in the tank and fill it with fresh gas (good quality gas, not the cheap stuff). You should notice a difference as early as 1/4 tank used, but try to run as much of it out as possible before refilling. If that helps, but doesn't completely clear up the missing, do it again.

EDIT: I forgot something. I've used this to revive EFI systems when I was told I needed new injectors. []

 

[Ron Mc]

Great ideas! Thanks. I'll go to an auto parts store to get some of the Berryman's B-12 and also get a price for a ignition modual as well.
This has been a great experience for my son and I. Fixing the truck and getting greasy together. I personally wanted to work on it with him so that he appreciates his truck more than if we just took it somewhere. We've had a great time replacing lots of parts and last weekend we replaced the transmission filter and fluid. That was a mess![]
Once again Thanks for the ideas.

 

[Nolan]

Careful what you put in tank as o2 sensors can be damaged. I have never put b-12 in as cleaner but I agree its the best darn stuff for rebuilding carbs. I wouldnt buy anything else. Funny this auto talk doesnt make me miss working on cars. []
Nolan

 

[alamocdc]

Me either, Nolan, me either. Personally, I'm glad I decided to go to school and put my knuckle busting days behind me.

 

[Nolan]

Well my departure from the auto industry was much more dramatic! Had a improperly racked car that fell off and crushed my ankle[:0]. And no I didnt rack it but when I went to inspect and correct it, the person let it down in anger and it slipped off and my leg was right in the way.
Nolan

 

[byounghusband]

Nolan,
What happened to the guy who dropped the car on you?[:0][:0]

 

[Nolan]

[}][}]Havent seen him since.

 

[Ron Mc]

Well I just got the truck home from the shop and noticed that it feels like it runs better when the AC is on. Does this ad anything?
Nolan, I sure hope you recovered from the guys hissy fit 100%!

 

[Dario]

I am in no way a mechanical expert but your reference to the AC sounds like fuel line related. Your truck prabably compensates for the load and increases the RPM that is why you are getting a smoother ride that time. Try Billy's advise to clean the injector.

 

[its_virgil]

Just drive with the AC on year round. [] Actually, when the AC is on the rpms may be kicked up a bit to keep the engine from straining when idling and that may mask the missing problem. I vote on a new 2006 F-Series Super Duty Harley Davidson model...I'm sure he would like it and may even let Ole Dad use it from time to time. Boy, it's sure nice when they finish college and are on their own....enjoy the time with your children....they grow up all too quickly. Mine are 28 and 25.
Do a good turn daily!
Don

Originally posted by Ron Mc
<br />Well I just got the truck home from the shop and noticed that it feels like it runs better when the AC is on. Does this ad anything?
Nolan, I sure hope you recovered from the guys hissy fit 100%!

 

[Nolan]

Ron,
Get around ok considering I have had 7 surgeries[] Not as good as I would like but heh. With AC on vehicles have idle step-up (because of extra load on motor) Which basically gives the motor little higher idle. Is the stumble right off idle/ Like when you leave from stop? If so then you may have a TPS (throttle position sensor) that is out of adj. Thats why I put this disclaimer before my post

This is a suggestion that asumes that all other areas have REALLY been properly tested and eliminated

hard to say could also be as simple as dirty fuel system as alamocdc suggested.

Nolan

 

[Ron Mc]

Well Don's suggestion is out! But I'll add the TPS to the list.
I realize this has nothing to do with pens but I really appreciate help from friends!

 

[Jim Boyd]

Berrymans came in two flavors. The one in a 16 ounce can as a fuel additive and a gallon size complete with a dip tray for carb overhauls. I thought the gallon style suff was outlawed by the EPA. My can purchased in 1987 is about worn out. Has anyone actually bought any recently?

 

[alamocdc]

Originally posted by n4631x
<br />Careful what you put in tank as o2 sensors can be damaged. I have never put b-12 in as cleaner but I agree its the best darn stuff for rebuilding carbs. I wouldnt buy anything else. Funny this auto talk doesnt make me miss working on cars. []
Nolan

Nolan, I've used it in a number of GMs (1994 & two 2002 models) and never had a problem with any of them. This is the only fuel additive I use and I don't have to use it but once or twice a year to keep things working.

Jim, I haven't bought a gallon dip can since 1995 and mine still works just fine. It seems like I saw one at Autozone the other day, though.

BTW, I also use about 1/4th of a can in my Harley tank when I store it for the winter. Keeps the gas from going bad and the varnish build up out of the carb and lines. []

 

[Texas Taco]

Originally posted by Jim Boyd
<br />Berrymans came in two flavors. The one in a 16 ounce can as a fuel additive and a gallon size complete with a dip tray for carb overhauls. I thought the gallon style suff was outlawed by the EPA. My can purchased in 1987 is about worn out. Has anyone actually bought any recently?

A co-worker was looking for the gallon container a couple of months ago and the parts house told him it was no longer available but they said nothing about the EPA.

 

[DWK5150]

Fords are notorious for the idle air bypass port on the throttle body to plug up. Very common problem you pull the idle motor off and spray it out carefully with cleaner. That can cause the problem you are having as I have seen it many times. But dirty injectors can as well. Just be careful when you clean it out as you dont want to wash the grease out of your throttle shaft as they are lubed from the factory. You wash the grease out you end up with a vaccuum leak that most people dont catch either. Your problem can also possibly be a vaccum leak as well easy test for that is spray lines with car and choke cleaner carefully and you notice a change in the motor running when you find a leak.

 

[leehljp]

Below are two web sites that offer free advice and suggestions on automobile and truck problems. They helped me in the past:

http://www.freeautoadvice.com/

http://www.batauto.com/cgi-bin/Forum/db_TalkToMeV2.cgi

 

[gerryr]

Call Click and Clack.[]

 

[whatwoodido]

When the ignition module goes the engine won't run as there is no spark. Fuel injectors sound likely to me. But it seems to me if they hook it up to a computer a lot of things would quickly be ruled out, and it could be the computer.

Drew

 

[Nolan]

I think you are confusing this with the ignition switch.

When the ignition module goes the engine won't turn over

 

[Ron Mc]

Nolan asked, "Is the stumble right off idle/ Like when you leave from stop?"
It happens right off idle then it seems to start missing again when I maintain a consistent 40 mph. Not before or after about 45 mph.
I picked up some B-12 while I was there to try that as well when I fill the tank up again.

 

[whatwoodido]

Originally posted by n4631x
<br />I think you are confusing this with the ignition switch.

When the ignition module goes the engine won't turn over

You are sort of right I did't mean to say will not turn over, I meant to say won't run/spark. I was typing faster than the brain was working.

Drew

 

[DFM]

Originally posted by Hemibee
<br />

Originally posted by Jim Boyd
<br />Berrymans came in two flavors. The one in a 16 ounce can as a fuel additive and a gallon size complete with a dip tray for carb overhauls. I thought the gallon style suff was outlawed by the EPA. My can purchased in 1987 is about worn out. Has anyone actually bought any recently?

A co-worker was looking for the gallon container a couple of months ago and the parts house told him it was no longer available but they said nothing about the EPA.

I just got back from Autozone where they had the gallon of B-12 cans on the top shelf next to the spray cans of B-12.

 

[Nolan]

Drew that has also been my experience with every make but Ford as eventual failure will cause a non start condition.The problem I am refering to is a problem I have experienced in which the Dielectric material they used (seals unit and disperses heat) was inadequate and would allow the modual to overheat and cause intermitent diveability problems.
Nolan

 

[slink74659]

When my truck started doing that they replaced plugs, then a coil, then the fuel filter and then cleaned the injectors. Its better now.