Hello all... Im new and pulling my hair out. I have searched the forums and cant figure this out.

Here we go:
If i let the blazer sit for a few days, it will start and run beautifully. I can drive it to china and back. BUT... Once I try and restart it it sounds like the distributor is 180 out. Knocks, bangs, coughs. Let it sit a few days and itll start again.
There was a code when I first started messing with it. I believe it was a P0341, so I replaced the crank sensor and all the goodies in the distributor. Same issues, but no codes( i cleared codes and havent had it running long enough to throw another).

PS... When it sounds like its 180 out it will not start at all. Sounds like im gonna puke the starter out of the bottom. Yes i have sprayed starting fluid into intake. Its a timing problem somewhere. Wont start, and if i think it might it just diesels and dies.

But if i let it sit for a couple of days itll start right up

Any ideas?

 

So, you've replaced the timing sensors and it either runs great or not at all.

If you pull it in the driveway running great, shut it off.. restart .. wont start. Or am i missing how long it sits till it wont start? 5 mins, hour, couple hours?

Does it do that EVERY time or once in while?
If everytime.. humor me, leave it run when you're gonna park it, remove the FP fuse or relay and let it run out of gas. Let it sit till it shouldnt start, wait a hour hour longer and try it. Try that a few times.

If that makes no difference, try pulling the battery terminal off for about 15 minutes before you start it

 

Petty... Definately not a fuel problem. While I replaced sensors, I did a starter too. Battery was disconneced. Yes, everytime i run it, i cannot restart it. When i crank it, it pops out of intake side and exhaust side just like installing a distributor in your 1970 small block chevy 180 degrees off. It pops, siezes like theres water in the cylinder(telling me that it is firing at or around BDC) What tells the computer to set timing while starting? Like i said, when it runs i can sell it as a new truck... beautiful. Only when i try and restart it kicks like a mule and huffs and puffs and wont start. I had to replace the starter because it snapped the nosecone off the original from misfiring while i was trying to start it(cranking)

 

Anyone have any ideas?

 

coolant temp sensor? i believe that controls the amount of fuel by sensing if the motors hot or cold?

 

New update.. Just went to garage and wont start.... Seems like a fluke when irt will start.
This is not a fuel problem. This is a timing issue. What tells the computer where to set timing during crank??

 

ckp does but it's not like it decides to work one run cycle and not the next. If it's flaky, it tends to be flaky not dependent on start. Unless there's a lot of oil or water slinging around on a cracked insulator but even then.. might run a while then goof up.

Well then... lets go back to 'oldtimey' stuff
25 years ago everyone would be saying 'change yer distributor cap and rotor'. That can give you the exact symptoms you describe.
How? When there's water condensed in it.
How'd the water get in there? Dunno but worth a shot.
There's a vent at the base of the dist plate that must be kept clear. I know that from other threads on dist problems

 

Petty... I have changed crank sensor as well as everything on distributor. New cap, rotor, modules etc. Im in a very dry desert climate and blazer is indoors.

 

Ah well.. what havent we tried.. the dark test? In dark crank and look for sparkover.

Bad wire harness ground connections (2) back of engine?

Wiggle and tug harnesses while cranking?

 

you said you changed the crank sensor and the cam sensor.....correct? did you happen to do a ckp relearn after the install? if not get it towed to a shop that can do the relearn.