88 cheyenne...timing problems

[Z85MAN]

how do i find out the timing on a 1988 cheverolet c1500 4.3l v6?the motor i was told was pulled from a 1987 s-10.the distributor came with it.i tdc'ed the motor and have set the #1 plug wire at 6,7,and 5 oclock positions.on 6 it wont fire at all,on 7 it will start but not time up correctly.it idles very roughly and carbons up the plugs.the best i could get was a lopsided lopeing at idle.if i pushed it up on rpms.it would run .but i cant get a smooth idle .on 5 oclock it backfires thru the carb and starts fires.i am desperate and totally frustrated.i have been on this for a week now and changed everything.including the throttle body.i also changed the fuel filter.yes,i also used a timing light.gets the mark close but jumps between the o degree and 8 degree marks.also i was told there isnt any such thing as an 87 4.3l v6

[MT-2500]

Base time is set with the bypass wire disconnected.
The wire is inside cab under heater housing black/tan single wire
Dist turns clockwise rotation firing order 123456.
Base time is set at 0 degrees TDC

[Z85MAN]

Originally Posted by MT-2500

Base time is set with the bypass wire disconnected.
The wire is inside cab under heater housing black/tan single wire
Dist turns clockwise rotation firing order 123456.
Base time is set at 0 degrees TDC

thanks mt...do you know which dist post the #1 plug wire is supposed to be on?

[MT-2500]

The one the rotor is pointing to when the engine is at TDC compression stroke.

[Z85MAN]

Originally Posted by MT-2500

The one the rotor is pointing to when the engine is at TDC compression stroke.

unfortunatly,someone i think turned the motor over without the dist in it and may have readjusted the oil pump position trying to find it.thats what i was told is why i cant get it right .

[MT-2500]

Find tdc on no 1 cylinder/piston on compression stroke. not exhaust stroke.
The drop in dist and point rotor to no one wire on cap.

[Z85MAN]

Originally Posted by MT-2500

Find tdc on no 1 cylinder/piston on compression stroke. not exhaust stroke.
The drop in dist and point rotor to no one wire on cap.

unfortunatly it doesnt say which is no 1 position on the cap .i have tried to just put it at the no 1 wire on cap and with no success.the book shows three different positions 5oclock,6oclock,7oclock.none of these will bring it up right .thats why im turning to you all.i wish there was someone local i knew who knew something about this.im willing to bet it is something soooo easy that i would kick myself in the butt for not seeing.anyways,thanks for the info.

[MT-2500]

Get the engine at TDC on no 1 piston/cylinder. The make sure it is TDC compresson stroke.

Hold you finger over spark plug hole and crank engine. when you feel compression it is coming up on the compression stroke.
The catch it at TDC on the engine timing mark.

The set the dist with the rotor pointing to no one plug wire on cap.

The no one wire does not have to be in ant certain spot on the cap.

But with no 1 cylinder at TDC compression the main thing is the dist rotor will need to be pointing to no 1 plug wire.

Then put your plug wires in the proper rotation and firing order.

A repair manual should have a picture and instructions on how to do it.

The position of no 1 wire on the cap can be anywhere as long as the rotor is pointing to it when the engine is at TDC compression stroke.

Good Luck MT

[Z85MAN]

Originally Posted by MT-2500

Get the engine at TDC on no 1 piston/cylinder. The make sure it is TDC compresson stroke.

Hold you finger over spark plug hole and crank engine. when you feel compression it is coming up on the compression stroke.
The catch it at TDC on the engine timing mark.

The set the dist with the rotor pointing to no one plug wire on cap.

The no one wire does not have to be in ant certain spot on the cap.

But with no 1 cylinder at TDC compression the main thing is the dist rotor will need to be pointing to no 1 plug wire.

Then put your plug wires in the proper rotation and firing order.

A repair manual should have a picture and instructions on how to do it.

The position of no 1 wire on the cap can be anywhere as long as the rotor is pointing to it when the engine is at TDC compression stroke.


Good Luck MT

well,mt,i would love to say it worked .but,it didnt.i dont usually give up on something like this.but,after finding out they had the rotor out before i got it.then they walked away from it.i think it is time to see if i can get someone out here to take a look at it.a proffessional that is.i put an ad on a local website and got a response.i really appreciate your time and effort on this.it was welcomed and printed out so that someone else might be able to use it.....good luck

[MT-2500]

You are welcome.
Thanks for letting us know how it went.
You may have some other problem to.
After setting the dist you have to have good spark and fuel.
Good luck and let us know how it goes.
MT

[Z85MAN]

Originally Posted by MT-2500

You are welcome.
Thanks for letting us know how it went.
You may have some other problem to.
After setting the dist you have to have good spark and fuel.
Good luck and let us know how it goes.
MT

hi mt...well,got it going .it was the module.it showed ok on the tester but i decided to change it anyway.lo and behold,vrrrrroooom.running smoothe as glass..thought i would let you know.....mike

[MT-2500]

Originally Posted by Z85MAN

hi mt...well,got it going .it was the module.it showed ok on the tester but i decided to change it anyway.lo and behold,vrrrrroooom.running smoothe as glass..thought i would let you know.....mike

That sounds good.
Glad you got it and thanks for posting back how it went.
MT