hey guys i have a 1993 s10 blazer 4.3. it was running very rough so i did a tune up, changed the fuel pump/filter, coolant temp sensor, TPS, and EGR valve. it was still running rough so i took it to a shop and they said it was the CPI (spider) assembly. the truck crank up and drove in to the shop as usual and after i changed the unit out i went to start it and it wont spin at all. almost like its locked up. i pulled the manifold off and noticed the main fuel line leading into the CPI wasnt in all the way and gas the lower manifold was full of gas so were a few runners. when i checked the oil it had alot of gas in it too as im sure it leaked down. my question is would the gas in the crankcase alone cause it to not want to spin over at all? or am I looking at a bigger problem. im confused since it was spinning over fine before and now nothing. also the starter was smoking when trying to spin over so i will have it checked tomorrow.


Thanks in advance,
anthony

 

Fuel can flow past the poppet nozzles down into any one of the cylinders if the intake valve is open even just a bit. A cylinder full of fuel will cause the engine to lock up.

Do yourself a favor and get new internal lines. Unless the lines were new when the spider was replaced, the likelihood that they will hold pressure is very low.

 

thanks for the quick reply. I went out this morning and changed oil and pulled plugs and it spun over. i went ahead and changed the internal lines like you suggested and it works great now. thanks again!

 

did u try to turn the motor over with a pipe wrench on the crank pully?
just to see if it hasent locked up on u

 

Forcing an engine to turn while it has a hydraulic lock can destroy the motor. Depending on the amount of liquid in the cylinder and the point of rotation when the hydraulic lock occurs, you can literally bend a rod and kill that rod bearing.

Back during the golden age of aviation (Especially WWII).. A flight line crew would walk the blades through on the old reciprocating aircraft engines. They would walk through I believe 27 blades. As the crew member was walking the blade through he would be feeling for resistance. If he felt any, the line mechanic would have to pull the spark plugs out of that one cylinder to let the gasoline or oil out of that cylinder.

If you watch old movies, you will notice that to shut an aircraft engine down properly, you kill the fuel, not the ignition. This prevented unburnt fuel from puddling in the lower cylinders.

Basically - NEVER BAR OVER AN ENGINE THAT MAY HAVE A HYDRAULIC LOCK!

History lesson complete.

Have a great day!

 

bull **** kristoph,
NEW LESSON
i said try to turn it NOT USE 1000 LBS and a 2' bar at the end.
its quite obvious if it will turn or not

you should be able to turn the crank pully with ease............
if it turns then check your starter or starter wire's.

if it wont turn try removing all spark plugs and try again.
if it still wont turn then most likley you seized your crank and fuzed the rod bearing to it. (most common)

if it turns see what fluid comes out of the cylinder and go from there.

not everyone here wrench daily or has a couple of k in tools like myself
or the knowhow to tear down a motor. most are just looking for a WHY to try to save a few bucks and try to fix it themselves.

p.s.
i have never bent a rod trting to turn an engine over by the crank pully
in my 25+ years of wrenching.

 

You said to use a pipe wrench. Pipe wrenches, as you know since you have thousands of dollars of tools, come in various lengths. Including 36 inches.

Like you said, people come on here looking for advice. Turning a crank pulley by hand is sound advice to see if your engine is locked up. Using a pipe wrench is not good advice for a novice to use.

I have never bent a rod turning an engine over by hand either. But someone who doesn't know any different using a "Longer-must-be-better" pipe wrench can.

I have also been around engines for a few years myself but I am not an expert by far.

I am sorry to have offended you but I still stand behind my previous statement. Dont bar over an engine that may be hydraulically locked. (Turning it by hand is not "Barring".)

I hope I clarified myself. This is not a personal attack.

 

no problem

and i still say use a pipe wrench

by hand, thats funny

 

Whats funny about turning a motor over by hand? I do it all the time.