Bullnose Enthusiasts Forum

1985 f150 running issue while driving

Classic

List

Threaded

43 messages Options

123

kyleroth48625

1985 f150 running issue while driving

My 85 will have the ignition timing jump around while driving it goes advanced then severe retarded all on it's own. I have disabled the computer timing by pulling the spout I can drive it on base timing and it did well for a while like that. But now while driving it will start misfiring randomly and loose power bad never really backfires out eather side though just misses and no power if you pull over shut it off for a minute it will usually run fine till it does it again. I have made sure all the guts in the distributor are tight and the distributor it self it's got a newer ignition module made no difference runs like a beast when it goes and yes new plugs and wires were done first. I have video of it doing it if some tells me how to insert I will

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

FuzzFace2

Re: 1985 f150 running issue while driving

Are you saying the timing jumps around with the sprout pulled?
If so the only thing I can see to cause that would be a timing chain with a lot of play.

Easy to check for play. Turn the motor by hand and set to TDC, do not turn it back to line it up perfect.
Now pop the dist. cap and keep an eye on the rotor, turn the motor backwards till the rotor just starts to turn and stop. Hope the rotor did not turn much, now look at the timing mark and you should be able to tell how many degrees it moved and will show the play.
I would say 5* is pushing it on play.

BTW you said plugs & wires how about the cap & rotor.
Dave ----

Dave G.
81 F100 flare side 300 six / AA OD / NP435 / 2.75 gear
http://cars.grantskingdom1.com/index.php/1980-Ford-F100?page=1
81 F100 style side 300 six/SROD parts truck -RIP
http://cars.grantskingdom1.com/index.php/1981-Ford-F100

kyleroth48625

Re: 1985 f150 running issue while driving

Yes cap and rotor are new as well the 300 is gear to gear that's the part that has me stumped. Bout the only thing I haven't done is rip all the wiring out of the thing. I got a 95 done Ben thinking bout doing some efi swapping if I can't find the issue

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Kyle - A couple of things. First, you have two identical threads, so can I delete the other one before people start commenting on it?

Second, on the video, this forum supports videos from Youtube, Vimeo and LiveLeak. You have to get the "embed code", then click the "Embed" button above, and paste the embed code between the ">" and the "<" characters.

I'll let you chew on that and I'll start a post re your problem.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

In reply to this post by kyleroth48625

I think I just typed this elsewhere. Since it jumps around with the computer out of the equation there are two failure points - the ignition module itself and the pickup in the distributor. If you've changed out the module and there's no difference then look at the pickup.

One of the issues with the pickup is the insulation tends to fail on the wiring in the dizzy. Pull the cap and check that out.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: 1985 f150 running issue while driving

Administrator

In reply to this post by FuzzFace2

I would say any play on a 300 would be bad, it is a gear drive cam, not chain like the 223. I would take a good look at the shutter in the distributor, make sure there is no damage and it isn't loose on the shaft, also look at the wiring from the Hall effect trigger and the actual pickup and it's plastic mount, there should be a metal arm locking the pickup in place, if it is missing or not securely attached to the pickup (plastic pin through the end) then your timing will go all over the place. Unfortunately, unless you have the tools to take the distributor apart and reassemble it, you are better off with a rebuilt unit. When the SPOUT lead is unplugged, timing should be rock steady at the specified setting, which varies depending on equipment installed (transmission) where it was built for and weight class. Since it is an F150 that pretty well eliminates the HD versions.

Question comes, since you refer to disconnecting the SPOUT that you have the feedback carburetor EEC-IV system meaning the distributor has a TFI-IV gray module on the side of the bowl. You should not use the later black module as the internal circuitry and external wiring changed. The gray module is referred to as a "push start" and uses an input signal from the start circuit to "push" the dwell to the maximum to aid in starting, the black module is referred to as CCD, for Computer Controlled Dwell, where the EEC adjusts the dwell to increase the spark voltage as needed. These were a 1995 model year introduction.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Ford F834

Re: 1985 f150 running issue while driving

Administrator

In reply to this post by kyleroth48625

I will throw in the disclaimer that I have only a novice understanding of ignition circuits and failure points... but I have had straight six Fords in the driveway most of my life and have the following observations to offer:

Twice I have had bad ignition modules, and recently one bad distributor pick up. When these items failed I did not experience misfire or running rough. The distributor pick up would cut out, but run smoothly in between. One module just quit and was dead. The other manifested as progressively harder starting until one time it wouldn’t start. Not saying these components can’t create misfire but that hasn’t been my experience.

Problems that HAVE given me rough running/misfire problems are: 1) Bad coil. That was a maddening one and I don’t want to talk about all the other parts I bought first. 2) Major vacuum leak. Mine happened to be a giant crack in the PCV grommet. 3) Broken distributor shear pin. This usually leaves you dead in the water, but I have experienced where the shattered pin ends would catch after a missed revolution or two and continue to run, slip/catch/run etc., but that wouldn’t be long lasting. I only mention this because it’s worth checking the integrity of that pin in case it is worn or allowing slop in the rotor.

Don’t know if any of that helps, but those are issues I have come across and things to check. I’ve also had carb and fuel delivery issues disguise themselves as spark issues, so if you are not getting backfire consider that the ignition timing may actually be fine. Not saying it is... just don’t completely rule it out.

SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2

Frank Wyatt

Re: 1985 f150 running issue while driving

In reply to this post by kyleroth48625

When you replaced the ignition module, you did use the heat sink grease right? Just beause it's new, doesn't mean it's good or could not have gone bad. My vote however is check the coil. The next time it does what it's doing, see if the coil is hot/over heated. I have had several coils to go bad and they acted up similar to the way you are describing and on all of them the coil was getting very hot.

1981 F 150 Custom 300 ci with a fully rebuilt 1968 240 head Carter YFA T-18 3.25 9" rear 2WD
dual gas tanks
1990 Lincoln Town Car 5.0 AOD
Home town Mc Kenzie, TN

85lebaront2

Re: 1985 f150 running issue while driving

Administrator

Apparently he either hasn't read anything or doesn't like the answers given.

Bill AKA "LOBO" Profile

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

I'm guessing his spam filter put the email notifications in the spam folder.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: 1985 f150 running issue while driving

Administrator

I noticed in his introduction he said he is a truck driver, in which case he might be on the road.

Bill AKA "LOBO" Profile

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Yes, that may well be it. Anyway, I sent him an email to let him know he has responses.

Gary, AKA "Gary fellow": Profile

kyleroth48625

Re: 1985 f150 running issue while driving

In reply to this post by Gary Lewis

Sorry yes I did read just didn't get time to work on it till now. I disassembled the distributor found that the plate that secures the rotor and the teeth to the the tone wheel was cracked at the weld so I put a different distributor in that was in good shape from another 300 I put new pickup and ignition module on it made it a quarter mile down the road and Bam runs like crapp it cannot run over 2500 and of it reaches that it's done just misfiring spitting and drying to dye I've checked all vaccum lines had many issue with t those in the past can the carb really cause the engine to just misfire. The car is the junk computer controlled one that I bought reman from nappa two years ago but wouldn't be surprised of it's junk

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Yes, a carb certainly can do that. I suspect that you do have carb issues.

Gary, AKA "Gary fellow": Profile

kyleroth48625

Re: 1985 f150 running issue while driving

Ok so I finally made time to work with n the poor girl more mostly out of neccesity my car lost the motor. I lucked into a carborator exact fit for the truck at my work brand new carb stickers and all never had gad in it that I can smell. A parts house threw it in the scrap pile as part of a clean out. Put it on the ole girl she runs pretty relably now still has a stutter to it but rpm and load make no difference now just kind of has a drum roll while driving I found why my timing was jumping so bad at base time the plate the rotor sits in had the weld busted on it allowing it to move a little back and forth so I rebuilt a used distributor with new electronics. Hold base time we'll now but does not seem to pick up any power when the spout is plugged in. I threw a new coil on again as well as a quick attempt to get the miss out. O drive the ol girl 80 miles a day now. Would be nice if I could get it over ten miles to the gallon . Any ideas on how to boost mpg it used to get 20 when I first got it. And how much can the feedback carb really change fuel flow

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

1986F150Six

Re: 1985 f150 running issue while driving

Administrator

kyleroth48625 wrote

Would be nice if I could get it over ten miles to the gallon . Any ideas on how to boost mpg it used to get 20 when I first got it. And how much can the feedback carb really change fuel flow

https://www.ford-trucks.com/forums/1325963-gas-mileage-recipe-4-9l-300-a.html

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

In reply to this post by kyleroth48625

Kyle - I'm not 100% sure what all you said, but let me ask some questions.

First, you said "does not seem to pick up any power when the spout is plugged in". But unless I misunderstand, your truck doesn't have a SPOUT connector. I've included the schematic, below, and it does have an STI connector. But my limited understanding of the STI is that it only causes the computer to flash the codes. However, connecting to it isn't going to change the "power".

My guess is that you have enough things not connected or not working such that you have no advance on the ignition. That happens when the computer sees a problem, like no input from one or more things that are supposed to be connected. For instance, if you don't have the feedback carb on the computer will know it immediately and probably not advance the timing.

There is no half-way on the EEC systems. They are either all there and working correctly, or if any input is missing they aren't happy and the timing doesn't advance.

Gary, AKA "Gary fellow": Profile

kyleroth48625

Re: 1985 f150 running issue while driving

Ok so I finally dug into the old girl again kinda set it aside when it started running even worse to where I couldn't even drive it. I made sure all factory conectors were hooked up didn't make a difference trued swapping carbs around again couldn't get it over 1500 even and barely running at that
I unhooked the computer and I can actually drive it now little stutter under heavy Accel but goes away if I let up on the throttle thinking fuel pump may be getting weak. Traced wiring looking for issues found one brown wire hooked into the oil harness broken fnd it weird the hat the coil has five grounds and six power wires not sure how it all works there

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Are you saying that with the computer disconnected it runs much better? If so, then the major problem isn't a fuel pump. It is surely something electrical if you electrically disconnect the computer and most of the issues go away.

So, how did you disconnect the computer? And, what's the other color on the broken brown wire? There will be another color that may be dots, hash marks, or a stripe. But without that I don't know what the wire is.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

This post was updated on .

A lot of this "will run up to X-RPM then loses power and wants to stall" sounds like a collapsed or clogged Catalytic converter.

"Runs better with the computer disconnected, or spout unplugged" points to a failed ECM.
Push Start TFT will run with locked timing with the computer not controlling the advance, but will die if it's in the loop.
Because spark is erratic or non existent.

If the PIP is going bad, even that won't work.

Got me on the "coil has five grounds and six power wires" thing though.

Just my two cents from what I can understand.....

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

123