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constructionDAVE 05-21-2013 03:13 PM

94 F150 4.9 Bad fuel replaced - wont idle
Hello...... I am the new guy and looking for some ideas on how to get old blue running again.....Dallas TX.

Warning…This is my first & a long post…… Truck has not been driven much in 5 years. The last two years only started and drove on the farm a few times, never very far. Prior to my current issue it has always ran perfect. Only has 100k miles on it and purchased it new – it is a California truck btw. Wouldn’t start about 8 months ago and my automotive savvy Buddy replaced the front tank fuel pump. Started immediately and ran great for a quick 20 miles then sat at idle for an hr and seemed fine when I turned it off. Sat a few weeks and the next time I started it ran like it was on 5 cylinders; crazy amounts of blue smoke. No power, could barley move it 50 feet. Sat a few months and I took out the new fuel pump and reached in the tank and grabbed something thicker than oil/varnish smell obviously (apparently Buddy had not paid attention). Dropped tank and cleaned about a gallon of sludge and 8 hrs later re-installed. I changed the inline fuel filter, blew air through the lines and hooked it up. It ran exactly the same, maybe 10 min then when hot I can’t keep it going, crazy blue smoke.
Unfortunately I like overlooking the obvious and have changed in order:
• Plugs
• Wires
• Injectors
• Cleaned all parts attached to intake.
Changed Oil and Filter – all other fluids new
• Vacuum lines
• EVP Valve
• Battery
• Throttle Position sensor
• Idle Air Control valve
In between each step (few days, weeks) I would start it to see if problem solved. When it was cold I could start it only. There was a loud valve lifter/sticking type noise that started about the 4-5 time/part I tried. But knowing it was fuel that started the problem I dismissed the noise for the time.

Then I found a diagram online about how the duel tank system works on this truck and beat myself up pretty good for a few days.
So now I have:
• Dropped rear tank
• Cleaned patched and re installed
• New fuel pump ect ect
• HEET in both tanks
• Seafoam
• New fuel
No fuel leaks
Gas caps are fine
Hose clamps are tight

Knowing the fuel in the rear tank was cleaner/new I turned key and primed a couple times switched and did the same on front tank. Pressed pressure relieve valve before manifold, a lot pressure and fuel smelt good-not the varnish smell/dark color that is stained into my skin head to toe.

Started up better but now I still have the loud valve noise and the longer it ran the more it went back to its original problem but no smoke until the end (only run 10-20 min and dies when hot) and I noticed a lot of moisture out the tail pipe for the first time.

It won’t run long enough to go and try and drive it. Don’t think its gas now.

I speculate that when I installed the new fuel pump 8 months ago and let it sit and idle and it sucked all that bad gas throughout the whole system it ran ok because it was hot. Once it cooled off it had gummed up or clogged something in the gas delivery, emissions, or air department and that’s why I started at the tank and went forward. I would love to go drive it but have only made it a mile with the pedal pegged and not moving very fast before it warmed up enough to die. However that was before I did the rear tank this weekend.

Do you think that I need to drop the front tank again because it’s been running off and on 20 min at a time (10 times) for a couple months while circulating from the contaminated rear tank?

Catalytic converter clogged?

Pressure regulator valve?

Vapor Canister need cleaned or replaced?

How do you like the seafoam in the motor oil for a short time? I didn’t put much but thought it would help with the valve noise.??

Kicker is I need this truck to drive on the regular and I ran out of time to have it finished a month ago…..No clue-frustrated and need to stick to building buildings and not automobiles.

greasemark 05-22-2013 08:43 PM

With what has been stated, I believe you may have glossed over a few finer points that could be major problems.
First, you've done everything possible to the fuel delivery system (and rightly so), however, under everything in driveability, the engine is nothing more than a big air pump.
You might do yourself a great favor by dropping the exhaust pipe at the manifold, start it, and drive it a bit. See if it gets better. I'd bet it will, as fuel that was as bad as you describe will clog catalytic convertors faster then you can slap a tick.
If this doesn't help, you could do a basic fuel pressure test; it should be 50-60 psi when the engine is running; and it should hold for at least 5 minuets when the key is turned off.
Then, there is the possibility that some of the fuel injectors are hanging up. It might help to flush them.
Let us know if that is something else we can help with.

constructionDAVE 05-25-2013 10:45 PM

Ford F-150 > 94 F150 4.9 Bad fuel replaced - wont idle
PSI on both tanks= 50 and held.

Runs better before it warms up and progressively worse

Took out the plugs and cleaned them and re-installed , no 1 & 3 were a little loose and all of them fuel fouled. Started up good and ran for 10 min and going to re-test now. Loud valve noise is still present but it does idle better with clean plugs.

Got the INNOVA 3145 code reader today and performed the first & second KOEO test EEC-IV Systems. What i got was..........

111 = pass

10 = separation code

122c = TP sensor below min voltage - replace with a new TP sensor?

332c = insufficient EGR flow detected _ solution anyone?

hanky 05-26-2013 04:00 AM

Hi Dave,
when you get a code it doesn't always mean that particular part is defective.
After you replaced the TPS did the code come back?
It is possible the EGR valve is not working and stuck closed or even slightly open which could produce a rough idle condition, however, as I believe greasemark stated in an earlier post the EGR sensor that is mounted on the top of the EGR valve usually was the cause for the EGR code. You need to be careful when replacing that sensor (white piece) because the three small bolts get very corroded and can break off when attempting to remove them. Soak them well with a good penetrating oil . If they break then you may need to replace the entire valve itself. Sometimes you can get away with just 2 of the bolts holding the sensor down.

constructionDAVE 05-26-2013 01:14 PM

94 F150 4.9 Bad fuel replaced - wont idle Reply to Thread
hanky, good call but it came a few hours too late. I had replaced both the sensor & TPS in the past before I had the code reader and taken back. My parts house up here apparently rents me parts for a day or two. So I had some time late night and decided to remove the EGR....I broke the 2nd bolt off.... was just going to inspect it & maybe clean it.

So I removed intake and all its friends and decided to remove pressure regulater valve because I would clean or replace while had a bunch a gunk in it- dirt rust. So I got a new one today; going to clean the injectors cuz it's easy from here and tap the bolt on intake ect ect. Found a vac line burnt too. So I'm hoping this will fix the problems. Only fear being the fix doesn't correct the valve noise issue and I have to remove it all again to get the valve cover off. But with 100k miles and no previous motor issues I'm hoping its not valve, rod ect ect. I did get the EGR sensor again as well to replace if I get another code once put back together. Thanks for your input.... I clearly need direction.

constructionDAVE 05-26-2013 01:18 PM

Can/should I put the battery in and pump gas through the manifold before I install injectors and regulator? Last time around I could not get the fuel line off at the manifold without damaging it. I have at least one set of every tool out there made to remove..... but didn't want to damage line or manifold continuing to force.

greasemark 05-27-2013 09:14 AM

Well, where did the junk come from? On a truck this age, it's a good bet that there is a lot of rust comming from somewhere.
You mentioned that the front tank was replaced, so how about the rear tank? I've also seen lines rust, and on something this old, anything could be a culprit.
As far as the codes go, the 122 (if it wasn't disconnected when the key was on) might come back; it would show itself as a severe hesitation/stall when accelerating or comming to a stop. Best bet is to get the engine running right first, though.
The 332 means the EGR isn't working correctly; make sure the valve 1) moves when vacuum is applied; and, 2) trace the vac. line from the valve to the vac. solenoid that controls it. Make sure that the valve has vac. aviailible to it when the engine is running and that it hold vacuum. It was real common for this line to rub through or break and not show itself very easily.
But stay on point. I'm sure you've replace the fuel filter; however, you might want to take it back out, turn it upside down so you can see how contaminated the fuel is thats been filtered since you put it in; if it is, it's comming from the tank(s). If not, then it's in the lines, and a good purging of the lines is a very good idea.

constructionDAVE 05-27-2013 02:12 PM

94 F150 4.9 Bad fuel replaced - wont idle
Thanks greasemark............The tanks were both bad when removed (should have replaced with new tanks - 1st side tank I ordered online didn't fit & ended up throwing it away, ordered it off the OEM part # too.) I cleaned everything out real good but the top of the tanks still had a little rust I couldn't remove completely. I ended up flushing the gas out of the rail last night into a towel. I reinstalled including new pressure regulator and checked & replaced all vac lines. Now removing that broken bolt in the aluminum intake has not worked out yet. I actually started small and worked up to the 5/16 + easy out and broke the tip off. I haven't found a bit out there yet that will core through it including left drill bits. I will try and find a easy out that is left tomorrow to mush the bolt out the back, that was what I wanted to do originally but couldn't find one over the weekend........ I'm guessing applying heat is too risky?

As too the fuel filter I will grab one tomorrow. Hope this round is easier. First time I had to remove side tank and cut filter apart to remove off the back fuel line. I ruined the insert/cage that goes in the fuel line but found the replacement easier than expected.

If I get codes or have issues once I'm back together I will drop before the catalectic converter as mentioned. I have wondered if I gummed that up but haven't got there yet.

greasemark 05-28-2013 08:37 PM

You're definitely on the right track. And one thing I didn't mention (but should have) is that Ford catalysts are not known for taking a lot of punishment; with the fuel that you said you had, then it's a good bet there is some plugging there.
As for the tanks, don't feel bad. There were at least 5 different metal tanks and at least as many plastic tanks made for those trucks. Even when I used to work for Ford, I used to get the wrong tanks; even with the part number supplied!

constructionDAVE 05-28-2013 08:58 PM

94 F150 4.9 Bad fuel replaced - wont idle
Quick question greasemark.... passenger side wheel-well...... coffee can with two vac lines...... whats that called? might have blown it across the shop with a bit to much air while cleaning what I assume was rust inside. And i ordered a new manifold and it will be in tomorrow. It actually cost less than the stuff i have purchased to get that dang bolt out......Thanks again. And speaking of plastic tanks...... when I replace mine down the road what are your thoughts on going to plastic and can I?

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