So I have a strong exhaust smell coming from my exhaust, and I think some may even be dripping out. I also had some fuel in my crankcase.


The truck is a 1987 F150 4.9L manual. I blew a headgasket, replaced the head, got the truck back together, and it ran great. I had to drive it about 40 miles home.
First 10 miles were great. Truck seemed to be running a little warm, but nothing like overheating (going off the dash gauge). then I got some backfiring/popping in the exhaust, and the truck started running like crap. Really rough.


The remaining 30 miles home used 7 gallons of fuel and the truck had no power unless I really revved it up, which also seemed to smooth it out a little (2300 rpm or higher).


When I got home I changed the oil. It had a few quarts of gas in it, so my bottom end is probably not very happy. Then I pulled codes.

KOEO
82 - Air diverter fault (TAD?)

KOER
12- RPM at idle out of range/ high
21- cooling temp sensor out of specified range or ECT out of range
33- EGR not closing correctly
42- no O2 switching detected

I checked the PCM just in case, and everything looks good on it. No leaking capacitors or burn marks anywhere. No water damage.

So at this point it runs really rough and it would appear as though gas is coming out the tailpipe.


What would be my next move here? Test fuel pressure and try to pinpoint it to a stuck open injector or too high fuel pressure?

Thanks in advance

 

Sounds like you have a pretty good grasp on it. After those tests you could try hooking up an air hose to the combustion chamber end of an injector and see if air comes out of the other end. Maybe stick it in fluid and look for bubbles.

You might get lucky on the engine wear. An oil analysis in two or three thousand miles would probably be worthwhile.

 

Gas in the oil says stuck injectors, pull the plugs if you find one or more wet then it is confirmed.

 

Thanks guys hopefully I can get it sorted out tonight.

I have ave some extra injectors from a 94 f150. I would think that they should work with an 87?


Edit: got impatient and pulled the plugs before work. 1,3, and 5 were covered in fuel. Looks like I'll be taking the intake off again. If only it were something as simple as half my dizzy cap being shot

 

Is this a dizzy cap?

 

Sure is, but the one in my truck looks like this

 

The perfect hat to wear during a field sobriety test!

Sounds to me like an electrical fault. From what I've seen in the service manual, the injectors on the 4.9 are wired in two banks of three. 1, 3, and 5 are on a single circuit. I don't know which side this circuit is switched on, but if it's ground-switched, and that ground wire ended up resting on something hot or sharp after the head swap, it might've melted or rubbed through and powered all three injectors directly. (Or, if they're + switched, maybe the wire abraded through against another + wire going to something else, with the same result.)

Hopefully the fault's not buried too deep.

 

lol



I thought it was strange that only the odd injectors were messed up. Thanks for the heads up, I will be checking the wiring out asap. That would be much preferred to taking the injectors out...

 

Well TooManyMIce you hit the nail on the head! My FI wires were resting on the AIR tube in the head, melting the wire coating, and grounded them out. Thanks again

 

Good to hear! Hopefully the bottom end didn't mind its gas rinse.

 

heck that is pretty clean now down there!


finally finally woo hoo hoo hoooooooo