Should my 1993 be able to run without the AFC banjo bolt?

[galakinokis]

Been trying to track down a problem...
My truck is a dog!! Cant really get it to go any faster than about 40, Its a 5 sp and has really no power up any hills, or any other power over 40 mph....! 1st gear seems fine, second is a little slow, third accelerates slow, and once i shift into 4th i loose all power and it seems like it is just running in gear- almost like having a 5h briggs n Stratton under the hood....

It is a new to me truck with about 140 on the clock... I can get it up to about 65 in about a stretch of 5 miles, it has to really work its way up the whole time.

Thought it was injectors, since it will choke it slightly when giving some throttle- bought brand new stock bosch injectors and still has no difference...

The turbo spools up fine, at wide open in N,

New lift pump, new fuel filter, finally opened up the AFC turned up the pump yesterday to see if that would clear out anything... nothing so far.

Did find out that there was only one plastic washer on the afc banjo bolt and another rubber like one attached to the cap.. and alot of plastic junk sitting on top of the diaphragm.

Tried the ether trick of spraying some around the fittings there to see if it was sucking any inside to idle differently...nothing happened

Started to back out the banjo bolt on the AFC to check for any leaks and it sputtered for a sec and kept on running! Seems like it runs the same w.o the bolt anyway?? Crazy...
Something inside there seems messed up or dirty... What do yall think??

BTW i also have a 1989 cummins that i could possibly switch the IP with the 93 to check to see if it is the problem- but that is my last resort, and it seems like it would fit?

[cmann250]

It should idle just fine with out that banjo bolt. That banjo bolt just handles air, not fuel. My bet is something is plugging your fuel lines somewhere. Crap could have grown in your tank and plugged the pick up almost shut, etc.

Welcome to 1stgen also

[galakinokis]

Well I havent dug into the tank yet... did chop off the exhaust behind the cab because i thought it was plugged up at the muffler...

i live in lafayette too. that is weird. drop me your phone if you want? my email is galakinokis@gmail.com

[cmann250]

Lafayette, IN? That's crazy I'll email you here in a second

[oldestof11]

I bet the AFC is fubard or the timing is severely retarded.

[ciamcoop]

The diaphragm in the afc may be torn and not opening the pump up as boost rises.

[u2slow]

I had a similar incident with my '90 D250. After I had the fuel pin out, the action rod (that contacts and rides along the fuel pin notch) got stuck in its bore due to old hardened grease.

The lack of power reminded me of my old '66 half ton with a 250ci L6 lol!

[01hillbillycummins]

^ mine did the same thing. pull your fuel pin out, and there should be a little pin that pops out after it. if not, free that sucker up

[cmann250]

I'm bumping this one for the OP. I took a look at it today and we found out that the guide pin, action rod, whatever you want to call it was not moving. It pushes back and forth fine with a screw driver, but it won't slide into the bore with when the throttle lever is actuated. It takes marginal effort to get it to move with a screw driver. I had zero expirence with a manual trans truck until today, but 1st and 2nd gear were fine, but shifting into 3rd made it bog down and it got more noticable going into 4th and even worse in 5th. Even with the pedal to the metal, the rpms don't increase and it accelerates so slow as can be. For the record, the truck is stock with the exception of a little star wheel tuning and rotating the fuel pin.



It sure looks like the tensioning lever pushes on the stop lever and the stop lever pushes on the guide pin. Something's not happening in there. When he gets ahold of a reseal kit, we may find out what's not happening in there. It could be as simple as the o-ring is boogered up or the pivot pin that the stop lever sits on could be warn, but that seems extreme.

[Hansen01]

For the record, the truck is stock with the exception of a little star wheel tuning and rotating the fuel pin.

Well theres his problem
If problem still persists when you get that figured out, maybe timing slipped back a little? Or maybe the turbo let some oil into the intercooler restricting airflow?

[cmann250]

If problem still persists when you get that figured out, maybe timing slipped back a little? Or maybe the turbo let some oil into the intercooler restricting airflow?

The timing marks line up and there's no sign of the timing case being opened up recently. I can't believe how under powered these trucks are stock, none the less with stock with no AFC.

[galakinokis]

Yeah no joke. I know it's not a Briggs n Stratton under there but sure feels like one right now!

Thanks guys for all the help!

[cmann250]

I believe the OP and I got it figured out a few days ago. We pulled the top off and freed up the guide pin even more. Between that, a 366 spring, and a very mild turn up of the fuel screw, it runs ALOT better and still isn't smokey. It will take hills in 5th that it would never have made before. Something good is going on in there