to start off it's a 1995 blazer 4.3 4x4 with a 166,00 miles. I had a problem with the fuel spider, and a small fire
under the hood. cleaned up everything and put the new spider in. now it back fires out the intake, and
wont start. I tried to buy a scanner for it but that was a no go, ODBII connector, and wont connect.
now it did mess up the wiring a little for some of the sensors, but not bad. I let it sit over night,
and it seemed like it was going to start but it wont just started backfiring again. any clues or suggestions?
I have heard it might have jumped timing or the distributor is out of whack. if so how hard to change the timing chain?

 

Did you remove the distributor when you did the work?

My guess would be the distributor is 180° out.

 

No, I did not pull the distributor out when I did it. is it possible it jumped timing? the intake was full of fuel and so were the intake runners and even the cylinders as well I had to pump the fuel out of three of them. I will pull the cap and see if the distributor lines up with cylinder one on the compression stroke tonight. thanks for the help! but keep it coming! Is it possible that the chain jumped a tooth? I can work on the newer cars, this distributor stuff kinda throws me for a loop not to mention I cant talk to the computer! errr!

 

O.K I could really use some help here. I did a compression test on it and here are the results
CYL 1 120 CYL 2 160
CYL 3 150 CYL 4 110
CYL 5 150 CYL 6 170
These reading are all over the place fuel pressure is steady @ 58 LBS
could it have jumped timing? or are the head gaskets blown the motor only has 166,000 miles on it and there is no noise from the bottom end. any help at this point would be greatly appreciated!!

 

Squirt some oil through the spark plug hole on the #1 and #4 cylinders and re-run the compression test on those cylinders after turning over the engine for a bit. If the values pick up, the rings are worn more on those cylinders. If it does not pick up on those cylinders then it could be a headgasket issue or a valve issue.

Fuel pressure seems to be a bit on the low side as well. 60+psi is the requirement for the CPI (and SCFI) motor.

I would be more concerned with the wiring. Inspect all of the wiring. Any wiring that has been charred or has become brittle, cut out the affected section and replace with new wire.

 

O.K squirted some oil into both cylinders and retested and they came up to 150 each. I will go through the wiring. the connections look the same as on my 94 blazer so it should be and easy fix. could the wiring cause it to back fire out the carb? I rolled the timing mark together and it looks like it is a little advanced on the distrubutor but not by much. also how about the crank position sensor does that affect the startup on these engines?
Thanks for the help!

 

O.k here is an update took the timing chain cover off to replace the timing chain thinking that it jumped a tooth. it did not but seems to have some slack in the chain on one side. might as well replace it but it did have about two gallons of gas in the block! drained the block and need suggestions on how to re-prime the bearings before we start it up. O.k here is the big question how did it jump 180 timing in the distributor and how do I get back to where it belongs?

 

It's running!!! I finally got it running with the help of my friend. I was putting the distributor in the way my book says or at least how I thought it say and it was just one tooth advanced! my buddy put it in proper location and it fired right up!