Ok so heres the deal.... cylinder 5 blew the head gasket and of course I tore it all down and fixed it. (I didnt have the money for machining the heads I know not good but I just dont have the funds but need my truck).

Background info on the truck... 1995 GMC Jimmy 4.3 vin code W, OBD II, "Flat" distributor cap.. Should be all you need..

Well the truck has fuel and has spark. Im taking my fuel pressure tester out to where the truck is at tomorrow to make sure it has sufficent fuel and Im borrowing a compression tester to make sure that the compression is good and hopefully also Ill have a code scanner to see if any sensors are bad. So with all that covered any other ideas Im not thinking of here? It turns over almost acts like it wants to start and will backfire every... hmm Id say 15 to 20 seconds.. Not sure of how many revoulutions of the engine. I cant figure this out so any help would be certinly greatly appriciated.

BTW it has a brand new fuel injection system (CPI set up gotta love it) and a new distributor as well. What Im thinking is, that the rotor button isnt lining up with cylinder 1 on the cap at TDC. So I need to make that happen but how considering these engines are "self timing" Im tired of fooling with it and I need my ride. I know Ive overlooked something!

 

Sounds like you may have the distributor installed wrong. Remember, #1 piston needs to be at TDC on the compression stroke, not at TDC on the exhaust stroke.

 

Thanks for the idea. Ill check tomorrow and see.

 

Ran a compression test... numbers as follows.

Cylinder #1- 130
Cylinder #2- 130
Cylinder #3- 45
Cylinder #4- 15
Cylinder #5- 125
Cylinder #6- 140

So what in the hell did I do wrong to get such low compression on both center cylinders? Am I looking at a full rebuild now or? Any help is apprciated

 

In your initial post, when you said: "cylinder 5 blew the head gasket", what exactly happened? Did it overheat? If so, it's possible the heads, and/or the block deck are warped. You need to lay a good straight edge (borrow, or rent one if you have to) across the mating surfaces and check. This should be done anytime you're going into an engine that's experienced overheating. Also, did you get all traces of the old gasket off? Were the heads properly torqued? They need to be brought up to the proper torque value (with a torque wrench), in at least two, preferably three, steps, and in the correct sequence. Which starts in the center and works out, as shown in the manual.

 

if #3 and #4 are that low you have a problem on both heads. I would check again on the compression I know #3 is a pain to get to

 

The heads were torqued properly with a torque wrench in the proper three step sequence. Cylinder 5 at the back (closes to the firewall) is where the gasket blew through at. It is possible the heads are warped but I didnt/dont have the funds to do anything about it and I know thats not the right answer at all but when funds are short funds are short and I need my truck. Im going to try to re-torque the head bolts again and see if that helps.. If not I guess Im pulling the engine for a slow rebuild as funds become available. Good thing I work a mile from home.

 

well someone gave me another idea on my compression issue. I possibly over torqued the rocker arm bolts and the valves on those center cylinders are just stuck open. Sound likely to yall?

 

It's possible. Recheck the adjustment and see.

 

I ended up pulling the whole engine. At almost 200k I figured screw it Ill rebuild the whole dang thing. So its in the begining stages of teardown and hopefully off to a machine shop soon. Anyone know a good place to get a full rebuild kit from? Ive done some research with little luck.