1986 S-15 Timing issue

I have a 1986 S-15 2.8 V6 4x4 truck and recently checked the timing on it and saw it was running extremly high. I would get at about 30 some degrees advanced. I turned it down to approx 10-11 and now it starts like a dream, yet i have no power if i put the pedal to the floor, or if i just drive normally it seems to wanna hesitate and surge then go. Shifting into neutral often makes it idle irradically and seem like it wants to die/stall.

Im pretty lost on this issue, i resolved the poor gas mileage, non-constant idleing, and poor start idleing with the timing but it seems like something else is wrong. Anything would be greatly appreiciated. Before adjusting the timing, the truck would start and run like its only got 2 or 3 cylinders firing and then evens out later on. this doesnt happen anymore now

Set the timing mark to zero degrees. Pull the distributor cap using white out mark where the rotor is and on the side of the distributor. With a wrench on the crank bolt turn the crank with somebody watching and telling you when the rotor starts to turn. Stop at this point and check where the timing mark is at. Anything over 15 to 20 degrees your timing chain is stretched.
Remember when you get to the mark go a little past and turn it back then go forward.This is before you start.

would it make a difference if its a timing chain? its not a belt can they still streatch?

Believe it a chain will get worn and stretch. A lot of chevy's have a plastic gear which will wear. I was trying to help you find the problem with removing the timing cover which is 90% of the job. Remember your bicycle when you were a kid.

Does your truck have a throttle body (fuel injection) or does it have a carb (varajet)?

When checking your timing, did you pull off the vacuum advance hose and plug it?

Base timing on my '85 S10 2.8L is 12 deg BTDC......

Thanks rhandwor.... I should probably check my engine for a worn chain too..

mike
85S10

Hey sorry i havent reposted quickly, my midterms are extremly fustrating.

I manged to get the timing chain cover off and found that it seems to be fine, its tight and theres no give in the chain.

After chaning the plugs, wires, cap, rotor, checked the vaccum pressure (got lots) Im at a loss for words to figure out why the truck is running so horrible.

After first starting the truck it runs fine for the first 10 mins or about 3 blocks of driving after that it tries to stall and then revs upwards of 1800 and stays there for some time and comes back down to 1000. while driving it sounds like the engine is missing while driving and accelerating.

anything else to check?, im getting to the point to take it to a garage which a college student cant really afford at the moment lol

cheers

btw my truck is TBI fuel injected model

If I remember correctly you have to disconnect a wire set the timing and then plug in the wire. This should be in the haynes manual. Then you have to be sure the computer advances the timing. If you have no manual I can go out in the garage and check.
After this is done you should check the fuel pressure as this can cause loss of pressure.

Ok, redid the timing on it as it says with the haynes manaul and its still acting like it has been, waiting on a fuel pressure tester from a friend

Ok took some time, and i managed to get a fuel pressure testor and it read around 20 psi. Now shoudnt the fuel pump be pushing around 65psi?
20 psi is a little low?

thanks

If this is a throttle body it should be 9 to 13 psi. Check for restricted fuel line on the return side. May be a bad fuel pressure regulator back bottom of throttle body.

Replaced the fuel pump, and it runs beautifully doesnt stall anymore. runs smooth. Had to re do the timing on it due to the old pump, its around 10-11ish

But with one good thing comes another, i have no heat now, (which i would rather have in -45oC weather lol) i ran the truck for an hour and nothing but cold air came through. Yet yesterday i had heat after 1/2 and before that i didnt have heat. If there is no heat does it always mean that the heater core is plugged or could it be something else just a general question

thanks for the help

If the heater core is plugged you can check by disconnecting the hoses at the engine and put a hose on one end if the water flows freely it isn't plugged.
I would check if you unplugged a vacuum hose when working on the engine. The heater control has dampers which have to open. the have vacuum operated cylinders which open and close them.
Feel the top and bottom radiator hoses you could have a bad thermostat.

When feeling the rad hoses the top one should be warm and the bottom one cold/cooler?

As the water is supposed to be circulating they should both be warm. Feel the hoses on another car that has good heat. They should feel the same on both vehicles.