97 F150 4.2 5speed V6 Idle Problem
 

All right so here is the deal, Ran my truck down really low on gas then my gas light cam on followed by a very rough idle consistant though sounds like helicopoter or motor bike. Anyways got some gas then check engine light came on and then would start to flash when i drove, then it would go solid. Used a scanner and had a misfire in cyl 4. Im in the process of moving so all my tools are packed up and away so i did some basics.

Plug wires needed to be replaced so swamped those out
New Plugs.

Nothing changed so i thought i would bring it in to a mechanic.
Mechanic said it had great compression. But did not have any missfires in cyl 4 but in 1 & 2 real time. I new it had spark but he said for kicks he would throw a coil pack on, said it kinda? made it run better. Then they told me my injectors were all working correctly on the electric end but said they were not flowing good and they could be plugged. He recommend me to have them cleaned. When i heard the bill would be up to around $1000 dollars i thought this was crazy so i picked up the truck and took out the injectors my self? Brought them to Injector Dr. and he said they were not the bad flowing at about 90 % and after cleaning flow charts were where they should be. Right then i new the injectors probably were not the case, put them in and new fuel filter. Still runs rough at idle and when going around 30 plus and stomping on it i can here it ping or miss, but cant get a code to pop up.

MAFS sensor looks good clean sprayed it nothing.
PCV Valve was coated with gunky oil but removed it cleaned it and started the truck and it has vacume.

Things i have not messed with our tested because i dont have correct tools are.

EGR
FUEL PUMP


I dont want to go and throw parts at it but i also dont have my tools to diagnoise components. I want to put a new coil pack on just to see what they meant by in kinda made it run better, but i kinda dont want to dish out money for kinda results?

Not sure where i should go from here. one thing i noticed was when i fired up the truck in the shop and warmed it up for a second i noticed the exhaust on cyl side 123 were hardly warm but the other side of the exhaust was hot. Kinda goes hand in hand with cyl 1&2 not firing maybe. Also after driving it some times its really hard to start like its flooded. The mechanic even said he flooded it out and had to let it sit at night.

I really dont want to bring it back to a mechanic because it cost me 250 just to have him tell me it was bad injectors?

Sorry for the rambling, If there is any help or a plan of attack i should follow please let me know.

Thanks again.
Mike

Witch it idleing.... Get a pair of well insualted chanell locks and gloves.. and pull a plug wire off one by one... if the idle dont change when you pull a wire off.. that means that is the cylinder not running.. i would start on that side that has the colder manifold

Thanks i will try that tomorrow

I started the motor up and let it idle then i started pulling the plug wires off on each cylinder to see if there was a change, Cylinder 1 & 2 made no idle difference and the rest of the cylinders made a huge idle difference. I figured this had something to do with the coil pack, so swapped that out today and nothing. Starts up fine and when the motors cool it idles pretty good. Then as i rev it a few times and get it up to temp it starts doing its harley sound kinda of a consistant putter? Also when driving in 3rd gear and up under throttle i her a funny noise kinda of a pinging squeal? What next compression test? Only thing i have not checked is fuel pressure, will try that later this evening.

Any thoughts? What are signs of low compression, gunked up plugs?

I would put new plugs and wires for sure... Also inspect your old plugs.... keep them numbered so you know whtich one came out of what hole... I would also change the fuel filter.... If its still acting up i would start with a fuel pressure test


edit... In your first post you said the mechanic did a compression check..???... if he didnt do a compression check i would do one...

ran a compression check, cyl 4,5,6, 170, 170, 200
cyl 1,2,3 170, 95,95. Going to do a wet test in a min, just noticed a little coolant puddle up above my powersteering bracket? Head Gastket? with #s like that what do you suspect

miles 160,000

Let me know what ya find out my 4.6 is doing the same thing