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95f150 4.9 300

Hello everyone, I'm new to this site and hoping for some good input.
I have a 95 300 straight six that I drove at least 100 miles a day before I parked it for about a month and a half, due to the start of a new job.
Now here's the deal. When i parked it, i had only had very little fule in it...tried driving it a couple weeks ago, and ran like crap, and everytime I tried to increase speed it wanted to shut down, no power, falling on its face. So I started down a path of trying to fix the problem.

I applied Seafoam to a tank full of gas-no help.
I changed spark plugs and wires no help
I changed idle air control valve, no help
I changed the map sensor, the throttle position sensor, fuel pressure regulator, then took the truck down and had a professional power injector cleaning done and codes pulled. Had about 8 different codes...
Then I changed an in line fuel filter located on the inside of the frame rail, the coil next to the distributor, adjusted the timing the best I could via the distributor, I removed the harness for the ECM/PCM cleaned the post/pin terminals and plugs thoroughly and applied dielectric grease. I have also tested the fuel pressure and checked out good.... it will now idle fine, but still will not power through gears and shift correctly and falls on its face the moment a slight increase of the gas pedal is demanded...
I've now noticed that when I try to operate the throttle while in park, and try to rev it quick and hard, it sounds as if it's making small internal backfires but only will blow a small puff of black smoke when I let out of throttle and it comes back to idle for a second then clears and runs smooth again... MY MIND IS BOGGLED!
PLEASE HELP!.... I dont have enough beer to solve this problem, or enough money...
 

dustybumpers

don't play well w others
You said you pulled the codes. What were they?
Stop throwing parts at it, fix what the codes tell you to fix

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Well, to be honest, the codes will merely suggest a problem associated with a symptom, and can send you down the same path as throwing parts at it....
I started by throwing parts at it and then had codes pulled...unfortunately some of those same codes were suggestive to things I'd already replaced.
I dont claim to be the smartest of men but as we all probably know, when it comes to early electronics, they dont directly pinpoint a fix.
I'm looking for.someone who has seen or heard of very similar issues with the same type of vehicle that could give me some helpful insight to my problem.
But thanks for trying to insult my intelligence. Have a good day.
 

dustybumpers

don't play well w others
Really?
I never set to insult you, only ask you what codes you had before you spent more money on it.
You come ask for help, talk crap, and walk away. Fine. Have a good day. Figure it out on your own smart guy

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nobodyspecial

Fire in the hole...
5,756
366
ND
Alright guys, relax. This is an overreaction on both sides

I havent experienced that problem, but hopefully someone here has, and will be able to chime in.

Welcome to the forum!
 

dustybumpers

don't play well w others
Ok, so can you post the codes so I can tell you how to test and see where the problem is?
I have owned and still own several 4.9 from 80-96, and do know my way around them.
My 89 f 350 4x4 4.9 zf 5 spd has 500,000 miles on it, and has never been to a shop besides mine.

I also have a 95 f 150 4.9 5 spd, and it is a maf not map.
There are 2 types of set up for 95-96 4.9

Codes a re a valuable starting point in diagnoses
 
I appreciate any help I can get, thx. I believe it may be the PCM just because of the multiple codes referring to the PCM.
"Cha-Ching"...Here are the codes.
112,117,122,126,327,513,552,
556,558,638, & 654...
 

dustybumpers

don't play well w others
PCM is probably fine
codes are separated into groups.
first is a EGR code, 112, IAT circuit low
The sensor on top of the egr says the egr is not opening and closing in it's full travel.
Test the EGR with a vacuum pump, if the diaphragm does not move replace the EGR

next is air and fuel
117 ECT circuit low

This circuit is looking for coolant temp, and can't find it, there is another code similar you have later, we will discuss that

122 TP sensor low input
Probably you have a bad throttle position sensor, that explains how the truck runs and idles sometimes, not others. I would replace it. It is located on the throttle body

next are ignition codes

327knock sensor low input
You don't have a knock sensor, pay no mind to this, it's a false code

next is speed and idle codes
513 throttle position sensorinput
I already told you to replace this

552, 558, power steering pressure sensor. Not a problem here, you didn't turn the wheel half turn when the scanner told you too

computer and sensor

638 drive by wire out of sync
You don't have drive by wire, not sure how you got this code
654 rpm output malfunction
you shouldn't have gotten this code either.


Soooo. looks like bad or dirty EGR, and a bad or out of adjustment TPS, and replace the coolant temp sensor for the computer.
That sensor is the one by the thermostat with multipul wires, NOT the one in the head with 1 wire for the gauge
 
Last edited:
Okay. It may be a few days before I get back to ya...gotta gather some cash.
Oh yeah, I've already replaced the TPS ...maybe I bought a bad sensor?
 

dustybumpers

don't play well w others
Tps may just need adjusted
I'll post that when I get back to laptop

At least your not overwhelmed now

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dustybumpers

don't play well w others

dustybumpers

don't play well w others
Any updates?

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dustybumpers

don't play well w others
Some people will take a small round file, and slot them.
 

dustybumpers

don't play well w others
Have you checked out rockauto.com for prices yet?

Other than shipping cost, they are usually hard to beat.
You ca also google a discount to put in the space, usually gives you 5% off.
 

dustybumpers

don't play well w others
Ya. Been there, done that. Best of luck on the work thing first, then the truck

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