This is my moms truck and im trying to get this thing fixed. Right now im getting 60lbs fuel pressure. I thought the timing had jumped because it was backfiring so i reset the timing and replaced the dist cap/button/wires/plugs.. It doesnt backfiring anymore while cranking but still will not start. I am getting spark. But whats weird is that i can spray starting fluid in and it makes no difference so this is getting weird. The engine does try to catch sometimes but never starts. Can the crank sensor be bad and still have spark and cause this? Im almost out of ideas. Need some help here

 

How is the compression? If the timing chain has jumped and you re-timed the distributor, your cam is still out of time. A compression check should show this.

 

^^^^Agreed... Also if your chain jumped teeth, I would say you have a slightly bigger problem on your hands than just spark!


I have NEVER seen a timing chain on a GM vehicle jump teeth unless it was badly worn (chain or sprockets). Check the chain if you suspect this, and change it if necessary... I can't recall if the 4.3 is an int motor or not, but most likely it is, and a broken chain can cause you alot of grief.

Anyways back to your no start, check the compression to see if it's still in spec as swart mentioned. Could be the ign switch?

 

It is not an interference motor. No worries there.

 

Ahhhh you're right... The 60* V6's from GM are interference, 90* are not. Bonus! No worries about replacing a head from piston damage!

 

Ok i checked compression and its around 180 all around. So that should be good.. Now i was doing some more checking since i had a helper today and it seems that if i check fire on a spark plug wire its intermittant and very weak spark. If i check it at the coil tower its popping. Now its more of a whiteish to orange spark though so could it be the coil is not strong enough to push the power through everything? or is the distributor cap possibly messed up... Thanks for the help

 

I am having the same problem. I am running out to go get a fuel pressure gauge, since the ooollll check it with a screw driver and get your hand saturated in gas only tells you if the pump is doing something.

It has the same problem. Kyle might remember, I had this problem when we had the big snow out here. I walked from 711 home, walked back and started the truck no problem. It has been running fine ever since. Now, it just wont catch. It sorta starts then just dies out. I tried some carb cleaner just to see if the car would start, nothing. Bad coil maybe?

EDIT-

Well, this was weird. I went to autozone, got the tester. Got back, and hooked her right up, (I must of not hooked it up correctly as I did not get a reading at first) but the truck started right up. Shut her down a couple of times, and starting. Everything is okay. So I pulled her in the driveway, hooked up the tester and was at 60 pounds. Now this sorta sucks, because the truck is running now and I cant diagnose anything as there is no "problem". I can't take this thing anywhere if it just decides to do it again....

 

I will be changing out the coil tomorrow morning after i get off work and I will post my results. Cheers!

 

Yea let us know, I have a funny feeling that my coil is going bad which is causing all this trouble.

 

Well it turned out to be the coil. Though before this the car had all kind of other problems i found. But this is what was causing the no start. Replaced the coil and it started right up. I had this thing sitting in my drive for like 3 months lol one problem after another i fixed. But alas.. its out of my driveway now. Woohoo!