no one can find problem!!
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New User
Joined: Mar 2004
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no one can find problem!!
I'm posting this for my dad. He has a 1986 f-150 EFI 302.
It started with a small miss and the more work that has been done it has gotten worse. it now bogs down, runs good some times and suddenly starts running rough,misses more often,etc...
He has had it to 4 mechanics and this is what has been done: Checked fuel pumps,checked compression,checked timing,checked all sensors and fuel injection,Checked and cleaned IAC,checked coil,changed TPS(throttle position sensor),Replaced plugs,wires,cap,and rotor (twice) the second time all motorcraft. The last mechanic he took it to had his own shop, but had worked for Ford 30 years and has a good reputation. He worked on it for 3 days,couldn't find anything, and says he has never seen anything like this before. Maybe we just need a different point of view.
Thanks in advance.
It started with a small miss and the more work that has been done it has gotten worse. it now bogs down, runs good some times and suddenly starts running rough,misses more often,etc...
He has had it to 4 mechanics and this is what has been done: Checked fuel pumps,checked compression,checked timing,checked all sensors and fuel injection,Checked and cleaned IAC,checked coil,changed TPS(throttle position sensor),Replaced plugs,wires,cap,and rotor (twice) the second time all motorcraft. The last mechanic he took it to had his own shop, but had worked for Ford 30 years and has a good reputation. He worked on it for 3 days,couldn't find anything, and says he has never seen anything like this before. Maybe we just need a different point of view.
Thanks in advance.
Lead Driver
Joined: Oct 1999
Posts: 6,779
Likes: 556
From: Kalispell, MT
You may have tried this already and just missed listing these, but the ignition module on the dist can do some really strange stuff - despite what the pros tell you.
Also the fuel pressure regulator on the fuel rail above the #8 cylinder will cause some of those symptoms but usually just gets worse.
Also the fuel pressure regulator on the fuel rail above the #8 cylinder will cause some of those symptoms but usually just gets worse.
Senior User
Joined: Dec 2003
Posts: 354
Likes: 1
From: Memphis, TN USA
Just make sure that the spark plug wires are pushed in tight to the spark plugs and distributor cap.
If it uses CKPS (Crankshaft Position Sensor), make sure that the wiring is not rubbing on the engine block or perhaps the CKPS is in need of replacement.
Is this Duraspark II, III, TFI? The TFI has problem of the TFI module located in the distributor body. Probably the module is acting up.
Make sure you don't have a bad gas (water in the tank). I would pour some ISO-HEET water remover along with the carb cleaner solution poured in the tank.
If it uses CKPS (Crankshaft Position Sensor), make sure that the wiring is not rubbing on the engine block or perhaps the CKPS is in need of replacement.
Is this Duraspark II, III, TFI? The TFI has problem of the TFI module located in the distributor body. Probably the module is acting up.
Make sure you don't have a bad gas (water in the tank). I would pour some ISO-HEET water remover along with the carb cleaner solution poured in the tank.
Senior User
Joined: Apr 2003
Posts: 237
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From: ipswich USA
TFI ignition module, is it a Ford or Aftermarket module? The aftermarket module are not the greatest. The PIP sensor in the distributor, sometimes suffers from the heat also.
JWRboss302
85 F250 HD 4x4 460 4spd
JWRboss302
85 F250 HD 4x4 460 4spd
New User
Joined: Mar 2004
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or perhaps it's just a piece of junk like mine. iv'e got the same year and same problem. sorry i could give you no help here. I think i'm just going to buy a chevy. that's all i have owned and i have never had problems like this. ford FOUND ON ROAD DEAD
New User
Joined: Mar 2004
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thanks for giving me an idea about posssible problem. sorry for the thread previous all you ford lovers lol! it's just when you buy a truck for 1500$ and you keep sinking money into it it gets frusterating. i needed to vent
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Fleet Mechanic
Joined: Nov 2003
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Reply to Jay Ford
I've found that adding a newer Chevy to the mix just makes things worse. I've literally had to replace every wire, relay, sensor and various other electrical components during my two month of Sunday restoration of my 1986 F250 EFI. This is my first Fuel injection system I've attempted in my 30+ years of backyard automotives. I know now why. Every single o-ring, fuel injector, and fuel line had to be replaced. I have not been able to find any sources (including Ford) on the o-rings that go on the Ford fuel line connectors and ended up reusing the old ones at approximately 80% sucess rate. Thank God, I had a friend's junkyard down the street which had four of these beasts in it so I was able to come up with alot of used parts (making pork out of pigs@#%)
After all this, I cannot idle the thing down without retarding it out to 30 degrees. I can now look foreward to pulling off the plenum and intake manifild again tomorrow (probably destroyin a couple more brown orings in the process that I can't buy new). The good news is that I've had the truck three years, gave little money for it, and will now have something decent that I can actually fix for the foreseeable future.
After all this, I cannot idle the thing down without retarding it out to 30 degrees. I can now look foreward to pulling off the plenum and intake manifild again tomorrow (probably destroyin a couple more brown orings in the process that I can't buy new). The good news is that I've had the truck three years, gave little money for it, and will now have something decent that I can actually fix for the foreseeable future.
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Elder User
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From: Kalispell, MT
jay ford...yer gonna hate me for this...but i gotta throw it out there...i've got an 84 F-150 4x4 300-6 4 spd that i paid 200 bucks for...i've had it for a year and a half...best rig i've had thus far...and only had to dump about 250 bucks into it since i've had it...
MontanaFord
MontanaFord
Posting Guru
Joined: Jul 2002
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From: East Coast
This may be a last resort for both lisagoud and jay ford 86, but you might have better luck ditching the fuel injection and putting on a carb. It would be really cheap to do, and you could get rid of alot of electronics that could be screwing you up. Or, for lisagoud, put on a mustang FI setup, I'm sure you can get all the parts for one of those, although I can't believe a decent Napa can't get the O rings...
New User
Joined: Jan 2004
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I had a simular problem with an '85 F-150, 302 FI. If the timing chain and gear has never been replaced the gear is made of plastic. The mechanic can put it in time but it will not stay. The problem that it causes it fuel to build up in the injectors. Have a mechanic pull the cover off of the timing chain and check the gear. Hope that this information helps.
Senior User
Joined: Oct 2003
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From: oxon hill, MD U.S.A
has any body tried the egr valve yet that has probable the problem got the same symtoms on my i6 and somebody from down the street said that it is the egr valve so i'm waiting for the part and this is my first ford and i dumped over5000 into it
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Spark Plug Gap
I want to post this as a general reminder about how important proper gap is. My brother had a problem with missing and poor performance. Went to the dealer several times, replaced wires, modules, plugs, O2 sensors, everything. He finally gave up. I looked it over several times and found an error in the service manual. The manual showed that the spark plug gap was supposed to be 43, when in fact it should have been 28! (This is a foreign car, so don't try and use these numbers on your trucks). After setting the gap to the correct number, it ran perfect! He is still in negotiations with the dealer about how they can't troubleshoot well.
Don't overlook the simple things.
Don't overlook the simple things.
