'94 S-10 4.3L Blazer Vin W Won't Start

[A Collins]

A couple weeks ago, after a weekend driving around in the snow my truck wouldn't start. The starter cranked the engine but it didn't fire off. I had to do a repair on the gas tank any how, so while it was down, I replaced the sender unit, and fuel pump. In addition, I replaced the fuel filter. Much to my dismay, it still won't run. It fires off with starter fluid.

I took the Plastic VORTEC cover off the top of the engine, and removed the device right under it, I think it may be the regulator, but I don't know. Any how, there is no gas odor when I stick my nose in the hole. Its also pretty grimey in there, lots of thick black residue.

At this point I'm at a loss. I'm going to have to assume that its the injector unit but honestly I have no idea. Any help would be much appreciated.

The only alternative is to *gulp* bring it to a garage, then I'm at the mercy of them. Who knows how much I'll have to pay. Wouldn't be a problem if I had money to pay for it but...

[A Collins]

I left one thing out: There was water in the gas tank.

[GMMerlin]

How much water was in the gas tank?
Have you checked fuel pressure?
Do you hear the fuel pump run?
Have you checked for spark?

[A Collins]

GMMerlin, thanks for the response.

There was about 1/4 to 1/2 a cup of water, estimated.

Fuel pump cycles and charges the lines when I turn the key on.

I'm assuming that I have spark because when I use starting fluid it ignites.

I haven't tested the pressure, but where the fuel line enteres the engine, if I depress the schrader valve gas shoots out.

[GMMerlin]

Check injector pulse..you can do that by disconnecting the 2 wire injector connector and installing a test light...if the light blinks while the engine is spun over than most likely you have a bad injector unit

[A Collins]

Great, thank you very much, you've been a ton of help.

One last thing:
1. Could I possibly have frozen water in the lines somewhere?

[A Collins]

One piece of the puzzle.:

I started my work on friday by replacing the fuel filter, after I relieved the pressure in the lines. Fuel dribbled out under gravity load, no problem. However, when I disconnected the return feed at the sender unit, the line was still pressurized. Is this normal? Does this indicate a blockage in the fuel system somewhere upstream of the feed into the engine at the firewall?

[Jethro_Canada]

I had the same thing happen to me when I dopped my tank out, turns out there was a mix up at the parts counter and I was given a low pressure TBI fuel pump. The TBI pump is much lower pressure than the pump required for the CPI in that Vortec. Time to connect a pressure guage. I think its supposed to be around 50-55lbs, the TBI is much lower anyways. If this is the problem make sure that they gave you the right sending unit, got mine all together with the CPI pump, and I had a low pressure sending unit, truck would run but no fuel guage

Good luck,

[A Collins]

God help me if thats the problem. I don't think i could bear the thought of having to drop the tank again.

[Jethro_Canada]

I think that I would check the fuel pressure before I forked out $300-$500US for a new injector assembly. Unless I've missed it, you still haven't done that.

[A Collins]

I checked the fuel pump, its the right one...Phew!

Your right though, I'm gonna check the pressure when I get home from work tonight.

Have you ever done the injector assembly? I'm thinking its an 8+ hour job.

[Jethro_Canada]

Injector Assembly is not a big job, I would recommend replacing the internal fuel lines inside the intake plenium also. You looking at 2 hours tear down, and 2 hours to put back together. I would just be very careful when you trying to remove the slotted bracket that holds those internal fuel lines and the back of the intake manfold. The stupid bolt is torx with lock tight installed right at the factory. Get a brand new torx socket when you take it out. Dad and I had hell of time getting that piece out. Just did mine a month ago. Both the pressure reg and lines were screwed.

Anyway if you do a search on the internet for "Blazer CPI Assembly" you'll find tonnes of free info.

Enjoy,

[Jethro_Canada]

Forgot something, it is possible to get a bad fuel pump right out of the box. Even if you down a few PSI that truck will not start. Maybe get the pressure checked.

[A Collins]

I'm in debted to you, thanks a ton for info. I disconnected the fuel feed to the back of the engine, and cycled the fuel pump on and off a bunch of times. There was still a little water in the lines. I felt like she almost wanted to go, but maybe it was some vapors that found their way to the intake. Of course the pressure tester I bought doesn't fit the Schrader Valve test connection on the fuel line. I'll have to dig around to find and adapter.

I guess I wasn't thinking about a possible bad fuel pump when I put the tank back up. I put some JB Weld around the top because I didn't like the o-ring seal, thats what failed the first time causing the initial leak. Now that tank is sealed up tighter than a whales @ss I'm praying to all known gods that its not the fuel pump.

Its good to know that the CPI Assembly isn't that bad. I'm wondering if water in the tank could have fouled the CPI?

[Jethro_Canada]

Not sure about the water thing on the CPI, I'm just a guy with an old truck and no money to buy a new one, I hate to sound like a broken record but if you get the fuel pressure reading thats ok then maybe a CPI replacement. Like I said before I would hate to see put a CPI Assembly in when you had a bad pump. I remember when my pump went, I was going through some hardcore snow 4x4 for like an hour on the way to the inlaws, shut the truck off and it wouldn't start again 5 minutes later. Pump was dead.

No too sure about that JB weld instead of sealer ring on that tank.

Anyway if you can get that pump in then you should be able to install the CPI assembly, just take your time,