What the heck is goin on????

[hunterguy86]

I have an 86 K5. 305/700R4/Np208. This truck sat for a year and a 1/2 before I inherited it. As soon as I got it i changed engine and transmission oil, cap, rotor, plugs, and put on a K&N. Wires were still good. They were put on right before the truck was parked. I rebuilt the stock Qjet. I got back from college this week and got in to drive it. Sometimes it runs smooth but other times it sounds like it has a slite miss. Also it diesels when it I shut it off sometimes, not all the time however.

It had old gas in the tank but i filled up w/ superunleaded fuel and it ran fine. Now that I got through that tank, these problems have come up.

I am i pickin up trash in the tank?
Could it be the timing?(suggested by my grandfather)
Where should I start?
Maybe try some higher octane fuel for a bit longer? I used regular unleaded this past tank.
Sorry for the long post. Just wanted to give all the info I know to give.

thanks for all the help yall

Dustin

 

[Grim-Reaper]

Change the filters for sure. Sitting for long periods could have allowed condensation to form in the tank. Its best to leave them full so there is minimal air space for this to happen.


Check that the choke is opening. The electric element could be failing.


Also pull the cap and rotor and see if the mechanical advance on the distributor is hanging up. On my older vehicles I have had his happen a few times. the Distributor will have to be disassembled and cleaned. To do this remove the weights and then drive the roll pin out of the drive gear. Now you can slide the inner shaft out. after it clean a light coating of high temp lithium for lubrication.

 

[Corey 78K5]

How does the gas smell? If it smells bad then it probably is! If Your worried about the gas then You should drain it out and change Your fuel filter. Mixing new gas with bad gas will only give You new bad gas If Your engine is dieseling then You more than likley have a timing problem (8* BTC) Inertia can cause an engine to diesel but that is typically found in big blocks due to the larger rotating crank. You might also want to check over the distributor. It could have some slop in it causeing the timing to act intermittent.

 

[hunterguy86]

i ran all the old gas out. Could i be pickin up trash/water from the bottom of the tank?

 

[Corey 78K5]

i ran all the old gas out. Could i be pickin up trash/water from the bottom of the tank?

Sure! anything is possible. Also check and see if anyone ever put in an inline fuel filter somewhere on the frame that could be clogged.

 

[dyeager535]

The sock filter in the tank is SUPPOSED to prevent junk/water from getting to the carb. However, with enough junk, that filter can plug up, or it can have a hole in it, and the stuff has progressed up the fuel line.

 

[pauly383]

Dieseiling can also be advanced timing and the idle speed too high . Double check the timing and see if you can back the idle speed screw off some .

And also make sure the solenoid that holds the throttle opne when th a/c is on is adjusted right .

I had some dieseling at one time too , and the idle speed and timing was my fix . I like it set to idle at 550-600 rpm in gear , won't stall driving or wheeling at that rpm either