F-150 Spits, sputters, no power, stalls, etc.. HELP !!!
 

I recently bought a 1987 Ford F-150 4.9L Inline 6. Ran great when I got it. It will run just fine cold (most of the time) and then eventually start running horribly. Spits, sputters, stalls, under stress or at idle. It acts like its not getting ANY fuel.. but doesnt always stall.. infact it usually just bogs and idles really bad. I installed a brand new gas tank, fuel filter, etc... by the way its a dual tank, and the rear doesnt work. The side tank was rusty and it sucked alot up... but everythings new and I even put injector cleaner in. Thats all good. I cleaned the throttle body. the filters clean. I cleaned the plugs and sensors with the proper cleaner. I just DO NOT understand whats wrong. I don't have a scanner for the car and autozone and them guys dont do anything older then 95 anymore. atleast around here. I'm going to change the EGR, TPS, Distributor module, etc etc etc but I would rather have a good idea as to what it is before I go spending money on her. If anyone has ANY idea as to what it could be your help would be MUCH appreciated. This truck is my transportation, my work vehicle, and its also a 4x4 so thats what I do during the weekends. without it I have no work, no transportation, and no fun... haha

Clarify....

Is the check engine light on?

It rough idles only when engine reaches operating temperature?

Sounds like you need to buy a scan tool and pull some codes.

Check vacuum hoses and verify sensor connections. Read codes from the dash.

Just went through this. ORiely has an OBDI code reader for 35$. Easy to use. Mannuall really helpful about running KOEO, and KOER test.

I initially started with installing a mechanical fuel pressure gauge on the fuel rail. This will tell you if its getting fuel.

Get the code reader as you can use a paper clip method just I always lost count and did not feel confident as numerous codes spit out at once. At Pepboys a TPS was less than 20$, so chasing parts you'll be spending more on the second sensor than the cost of the reader.

INNOVA is the brand of code reader I bought.

Good luck.

Topfile. The Engine light is on Because I ran an aftermarket oil pressure gauge. it came on after I unscrewed the factory sending unit. And as the post says it runs good when its cold. I have checked all lines, etc. As well as the sensors and plugs as I have cleaned and checked them..

My buddy who owns a shop across from mine hooked it up and it read MANY things.. he cleared the codes and the EGR and Coolant sensor came back up. but codes will appear as a result of other codes popping up. He was in a rush and had to go we didnt have to really dig into it. Alot of smog and other things have been removed. prior to my purchase. and ran great for weeks.

And thank you GatorTodd I will def look into this tomorrow.

You don't NEED a tool to pull the codes but it makes it easier. You can buy the tool on amazon for about $20.

If it's running rough at operating temp but fine when cold it could be the ignition coil or any number of sensors that should pop up when you pull the codes.

Try disconnecting the vacuum at the top of the EGR valve when it stumbles.
If that clears up the problem check for proper EVR (EGR vacuum regulator) operation and vacuum line routing. There should be very little vacuum in the hose at idle.

O.k.

Before you spend any more of your cash to replace parts that may be good, give your computer a look.
Click this link:A9x ECM's (and same years ECM's) Failures Due to Age

My computer was bad and I did the capacitor replacement to get it working correctly.
Total cost for the repair was about $5.00 and a little time.
It doesn't cost anything to pull it out and examine it.
If you see any of the leaking capacitor things happening, or, at worst case, burnt IC chips/ diodes/ burnt board, etc., the computer will have to be repaired or replaced.

As the name of the link implies, our computers will fail due to age.

You've got so many symptoms that point to the computer failed/failing that I'd put this visual check on the top of your list.

Oh, and one more thing, if the computer is failing, it may not show any codes.

Just my thoughts,

Bob

MAN OH MAN !! this is alot of work for an old truck I payed a Grand for lol Everything was very helpful. I will check this stuff out soon and get back to you guys if I figure anything out.

Well what do you expect for $1000? After you get this all ironed out you'll likely be very pleased with the truck.

Couldn't agree more. :-X06

Bob

Yea, I mean I found it on Craigslist locally. Guy had been trying to sell it FOREVER! but I never went and looked at it. Finally gave in. Its definitely worth what I payed. Very solid truck. The paints shot and its just an older work truck. And the miles are unknown. its rolled and he had no idea what they were. so everyone was scared away from all that. But I looked through that and saw a solid good running 4x4. But now all this is happening and it SUCKS. I fiddled with it today. found some hoses that were cracked and missing. cleaned more plugs and sensors. did a bunch of stuff.. thought I fixed it... but NO it started running like crap after warming up. Its smoking from behind the engine. Dont know what it is you cant get to anything because of all the hoses, wires, and throttle body/intake etc.... And you can hear a suction.. Dont know where its coming from.. could easily be a gasket or something... But DOUBT its why its running like this... Would just leak oil or in this case.. smoke..... I dont think it could make it start running like crap after it warms up... but HEY! could be :/ but wasnt smoking and stuff before it started running rough... guess this is just another problem I'm running into...

If it's smoking behind the engine it's probably an exhaust leak or an oil leak burning off.

This will tell you if its getting fuel.
http://www.usber.info/a86.jpg