IRON DUKE chanes head gasket now runs very rough

[Jon Scully]

ADVICE / ACTION PLAN wanted:

The story:

Bought a nice 1986 s10 2.5 Iron duke 2wd tbi; Ran great but had a broken head bolt-- Got a great deal, took it home and took off the head, checked for true-- seemed good with my straight edge removed the broken bolt from block, cleaned the head, cleaned cylinder block, re-installed head, torqued all rockers to factory spec ...20ish cannot remmeber exact at moment. Put new fuel filter, plugs, wires, cap, rotor.

Hooked up all the wires and vacum lines...no left over parts.....start her up...

AND it ran, but very rough.....Like it was on two cylinders or the timming was way out.....shaking ... low idle.....only ran it for a minute max- and decided to take a breather.

I have done this sort of thing before with no issues.....so need a nights rest, some thought, and some of all of your advice....

What to do?

[Jon Scully]

sorry for the typo in the title lol

[truckdude239]

you valves are 2 tight there is no torque spec for the valves i'll see if i can find the propers adjustment for them ina few

[Jon Scully]

Maybe....but the manual said to torque for my year engine-- there is no adjusting nut like i've seen on other motors-- just the bolt/ rounder washer that holds the rocker down.....

BUT...If that was the case-- how much damage could have happened....bent push rods or worse?

thanks for the check tho--I will double check too,
jon

[lurch115]

it could be possible that the computer was reset and is "relearning" the settings. that and are you certain the MAP sensor is hooked up to the correct spot?

[Jon Scully]

Thanks for MAP question, I will check again to be sure: Keep the suggestions coming, I am building a list that I can go over.....when I get back to it.

To check for MAP operation...I will look into how to see if the MAP is good.

Again: I had no running issue prior to head gasket change....ran great, started with high idle, then idled down.....

[truckdude239]

http://www.hotrodders.com/forum/valv...5-a-23075.html CHECK THIS OUT

[Jon Scully]

Originally Posted by truckdude239

http://www.hotrodders.com/forum/valv...5-a-23075.html CHECK THIS OUT

Thanks! I had read this last night-- from my manual/etc I think I set it properly. But I will check tomorrow. The one mistake I may have made: I did not realize that each cylinder had to be set to TDC to torque the bolts down for its' rockers. I hope I did not screw up the cam. A stated before, I only let her run a few seconds per shot (3 times).

I will get the valve cover off tomorrow, and have a look see--

All of you advice is welcome-- This board is such a wealth of knowledge. I used to work in a forklift shop; but have since changed career paths...so It is great to have a place to come and chat about these things!!!