95 4.3l vortec will not start!!!!
 

Ok, Im sorry for the crudity but its been a long and disappointing day and Im out of ideas.


Symptoms prior to failure:
Weak idle
stuttering idle
lack of power
heavy missing and sputtering during rapid acceleration

parts replace post failure;
fuel pump
fuel filter
fuel pressure regulator
plugs
wires
cap
rotor
ignition coil


I was unable to confirm spark after replacing the coil. I was however able to confirm fuel passage.

Currently it will crank and crank with no fire what so ever.

I believe it does have a vacuum leak however I have not isolated it, cruise control does not maintain speed, however by pressing, set/accel the truck will accelerate. also it sounds like the cluster for the vent selection dial has a small leak in it.

Any insight of suggestions would be awesome.


Thanks in advance yall,
~Ben

First, I suggest you click edit and remove your phone #. NOT a good idea to post them.
Too bad you waited till you were in a deep pit to post on here, troubleshooting these things requires a plan and method.
Is the Check Engine / SES light on? Have you checked for codes?

First, you need to verify a strong blue spark, Yellow wont do. Use any clean plug gapped between 035 and 045. connect plug to coil output wire.
If strong blue, run FP pressure and leakdown test:
https://blazerforum.com/forum/tech-a...agnosis-23038/

If no spark, check for voltage at coil, key on. If oyu have a tach, does it bounce on crank?

CEL is not on, but in the past few weeks it has come on and shut off, since I dont have a scanner I have to go to the parts store to use theirs but by the time I get to the store it has shut itself off.
Tach does not bounce during crank, it will rise to about 400 steady until fire where it will resume a normal status or now will simply drop when I stop cranking.
I was fortunate enough to break down at work so the truck is not in my driveway, will have to confirm spark when I can get a ride back a little later today.

Where do I go if there isnt voltage at the coil?
Also, This happened both when I replaced the fuel pressure regulator, and when I double checked my work yesterday. the engine wont turn over after having opened the intake manifold, I had to manually turn the crank a few full revolutions in order for the starter to be able to crank.

Does the engine turn-over at all now when you turn the ignition key to START?

If not, then check the battery terminals and the connections to the starter for the + side and also check the - side to frame/block.

Quick way to test for voltage at the coil is to have the coil lead pulled out of the distributor cap and tape the lead so that the exposed end is about 1/2" from the block. This will check for spark. If none, then need to see if there is 12 volts going into the coil. Have to remove the connectors and probe with voltmeter.

I assume the engine was running prior to replacing the fuel pressure regulator??

Oh and nice name....not one I see very often.

Right now yes, but like I said had to manually turn the crank after having closed the intake manifold.


Yes, the fpr was replaced because it started dumping fuel, obviously running terribly. post replacement it ran great, the following day (yesterday) the truck died.

Yea, lol, I was thinking the same thing

Ok update, I finally got back to the truck yesterday, put the key in and it started, ran beautifully all day, as if it had fixed itself. At the end of the day, after multiple starts and stops, I go to start it and nothing. I confirmed good blue spark. My attention goes right back to the fuel pump as there was no pressure at the shraeder valve. This morning, I picked up a bosch pump, install it, crank nothing. Still no pressure at the shraeder. If I dump fuel in to the throttle body, it will start and run but only long enough to burn what I dumped in. Obviously there is a fuel pressure issue. But where?!?!?!

Lanny,
Fuel injectors clogged?
This is a tough one after replacing all those parts,i would have thought for sure it was the fuel pump or FPR!

Injectors are clear, but again, there is no pressure at the shraeder which is before the injectors

Was it a delco/OEM fuel pump?