4.3l vortec 96 Blazer seems to come back to the same problem about once a year. I had blamed the wife for letting the tank get too low then parking in our drive over night, the next morning no start. this time the tank is 3/4 full and i did find some trash in the filter. That said the pressure at the test connector was still 60+psi. i checked for spark and it has spark. I went ahead and changed the plugs. The engine acts like it is not getting spark. I have sprayed starting fluid into the throttle body while cranking and there is no sign of a sputter. What I am having trouble understanding is that even if the fuel injectors were not working there should be some hit and miss firing of the ether shouldn't there? could the spark be weak? But it does jump the gap when a plug is inserted into the wire and grounded. New plugs, add ether and spark it just seems like there should be a bang! Any ideas or explanations would be great. The truck was running great when it last ran. I had replaced the lower intake manifold 3 months ago, the spider injectors 2 years ago and all was good. The no start had always come out of it by changing the fuel filter. there again running is one thing but the no fire seems a bit different.

 

Check your cap & rotor. That's my current problem. I have to clean the points with a small file every time it sits for a couple days. If that doesn't fix it then the pump might be shot..

 

Thanks for the suggestions. As it turns out the cause was and I guess will always be getting bad gas. Like it was before at least two times the problem starts out of nowhere. The truck will be running great, and yes I have a personal relationship to the old girl and she has had many great days. OK it goes like this. The wife comes home and parks the truck in the drive. The drive is a slight uphill slope of maybe or < 10 degrees. The truck sits overnight and the next morning it will not fire. Crank, crank but not even a pop. In the past I blamed it on her letting the tank get too low. Three years ago I replaced the gas pump. Even with a buddy and without a lift it was the hardest thing I have done on the blazer. This is the 4.3L Vortec with the spider injectors.

To shorten this story let me say what I have deduced from these nonstart situations. First of all there was water and other gunk in the gas filter. There was some of this impurity in the line between the filter and the schrader valve I captured as much as I could when I took the pressure test hose loose. before putting a new filter on but after removing the old one I ran the pump probably a dosen times and there was trash but it became clean. I let the line drain from the schrader port down to the filter and then put the new filter on and then retested the pressure at 60+psi. As far as I know there is no way to "clean" out the individual injectors or the "injector block" without removing the upper intake manifold. i hope someone corrects me in any of this if they know how or better ways around the problem. In my case I am sure that some of the snot that I had seen in the filter and after the filter was in the injector block and was stopping up the injectors. i got the blazer going last night and it in hindsight was nearly but longer the process I had done before. After about 24 hours of head butting without any "fireing" even with ether in the throttle body new plugs I was again ready to give up. It just seems like you should be able to put starting fluid in the throttle body and get it to at least pop. Thinking the MAF sensor matbe needed air through it I even put the intake back on the throttle body before cranking it but nothing. For a shade tree mechanic like myself this is a real painful situation when you know you have all of the ingredients of a bomb and you can't make it explode. Last night I went and got 5 gallons of super unleaded, a bottle of Chemtool and filled the tank up to full. Now a rain storm came and could just get the front of the blazer into the garage. My neibor loaned me her truck to use to jump the almost dead battery off and I turned the key and I felt a pop. I hit it again and it sounded and jerked like there was no timing. This went on for at least 30 tries at 10:00PM the neihbors probably not happy but I was because this is the first life it had shown since the night before. The funny thing was the last time I turned the key it did the cough but instantly went to a smooth idle. Need I say how happy I was. My conclusion is that you do not know what you are putting in the gas tank. Even if you always go to the same station. My friend tells me that the gas stations used to have filters on each pump manditory by law but now they don't. I don't know that but for what ever the reason we are getting bad gas. I think that the spider injection might be harder to get to come out of this problem than those injectors you can remove externally. I am barely a mechanic but reading this forum has given me the confidence to do some things that have saved money and brought me closer to my blazer. 96 blazer I have owned for 15 years and still runs great what could be better than that. I am wondering if possibly adding a better filter maybe like the old sediment bowl type would help or cause other problems.

 

This all sounds very convoluted, I am trying to find in your read were you put a new delco cap and rotor on this baby. Wires would be nice also.

 

New wires would be 6 months ago. Same time was the cap. The cap was an AC Delco but had been a series of others before the last replacement. I agree to convoluted but I had hoped that the last post would be a question in whole to anyone that might relate to a similar experience. I had questioned the spark as to it being weak but I only compared it between a known new wire and the existing wires visually with a plug grounded. The integrity of the spark appeared the same but I did not look at all 6 wires. I tested the injector cap to find the injectors were being energized. Possibly a combination of a less than perfect spark being further reduced by water from the injectors with the end result being an engine that would not fire. With a days worth of "trying" how about this, There may have been considerable water in the cylinders. As I said the original plugs were wet. Had this not been my only vehicle it would have most likely set for a week and maybe longer. I can't replicate this but I would guess had it set for a week it might have fired right up. I do know there was water passed the filter and it had more of a goop consistancy. Had it not been there and in the injector block it would run as it does now which is first crank start every time. I need a second vehicle is probably the real cure, spittybay, you wouldn't have a spare Blazer for sell would you? Thanks for your help!

 

If any type of goop got passed the fuel filter the popet valves are likely clogged-up or at least not spraying very well.
You may just need to remove the spider (again) and get the valves cleaned out. I know this is not a real fun job, but assuming the spark you see is good...should have a nice blue color to the spark.

Wonder if removing all the spark plugs, jumper the fuel pump so it stays on, and then using the starter to turn the engine over for five seconds, wait 30 seconds, five seconds....and doing this 10 times would get the valves clear. Then blow some compressed air into each spark plug hole to get the fuel/water out. Replace plugs, remove fuel pump jumper and try to start again....???? Just thinking out loud....

Good luck and let us know what you do.

 

Holy cow!!!
It sounds like somebody dumped water in your tank or that station needs to be shut down.
Need a method of cleaning out the entire fuel system. Most likely a bunch of differant steps isolating each section, pump, lines, tank and injectors.

"I am currently dealing with the problem of excessive water in the gas tank. Because my car 97 BMW 528i utilizes a screen to prevent siphoning, I disconnected the fuel line immediately before the fuel filter and let the fule pump do the work for me. I also purged the upper end of the line (I actually blew air so that the water backed out of the filter). Although this was not an immediate fix, (i ended up flooding the engine and having to pull the plugs to let them dry) I did successfully remove about 3 cups of water. Next i will again purge the lines at the same place and possibly replace the filter which i fear may have become waterlogged. Hope this helps."

Found this over on another site so theres some stuff out there on how to do it.
Good Luck!!!

 

That would be the accessable fuel line between the tank and the engine. Then using the pump in the tank to see how the gas looks coming out before the filter. i jacked alternate sides of the blazer up to see if I would get a good suck of bad gas. I replaced the pump about 3 years or so ago and as I remember the pump is elevated in a plastic baffle keeping it from ever getting completely to the bottom of the tank. The baffle lessens gas sloshing around right at the pump intake. When it comes to being able to pump all of the water out I don't think you would ever be able to do that. I think that's what the Heet additive is supposed to do make the water burnable by the engine. That was three years ago that I had the tank off and that is the last time that I can say that I know the tank has zero water in it.
I like the idea of removing the plugs and blowing out each cylinder with compressed air and drying the plugs. With the plugs out you could spin the engine much more freely allowing the injectors to purge any water or gunk in the injector block and poppets and maybe not run the battery down. If I can have the presence of mind the next time this happens that is what I will do. Another idea I had after the fact was removing the injector plug and applying 12V to turn the injectors on for a short period of time. The injectors normally are powered on for very quick pulses. I don't thing they would be damaged by manually turning them on and off as long as it was intermittent. Let the pump run and then cycle the injectors then repeat.

This is a problem that it looks like is going to be with us from now on. You never know for sure when or where it came from. Somebody should be keeping it from happening.

Today the wife is off on a 300 mile trip across Texas, the trip that she started out on when this problem started. The Blazer is running great she reported so what can I say! The real trick is to not get thrown by the water issue next time it happens and proceed in a logical set of steps. Easier said than done when the wife thinks she needs to go somewhere. I appreciate all of your help!

 

I agree that the fuel pump will not 100% empty the tank...as you said. Only way to do that is to drop the tank and clean it out. Remove fuel filter and remove fuel lines from injector then use compressed air to blow-out the lines.

That is sure alot of work. I do not know just how well Heet works; or how much water it can convert. This stuff is not available where I am at for some reason, used to use it every winter when I was growing-up in our family vehicles.

Hopefully your wife does not get stranded somewhere in her 300 mile journey.

 

You and me both on the "stranded" wife. I asked her to not let the tank get below half full. She is back and had no problems. There may be some law against it but wouldn't it be nice to have a drain in the bottom of the tank. If you had the reason to think maybe you had bad gas or just to clean the tank out once a year you could flush it out. I know there are many reasons that it could be said to be "dangerous". Probably less dangerous than me and a buddy under the blazer in the drive taking the tank off on a cold night. That was the case when the pump had to be replaced three years ago. That was a job that is still #1 on the "wish I had a lift" list. The plastic shroud around the fuel pump is setup to prevent sloshing and picking up gas right off the bottom of the tank. It also tends to trap the last gas present right under the pump. More so if you are parked uphill as in my drive. I feel like when this water problem happens it is something like an unlucky draw with the last fuel that is in the shroud and next to get to the pump being contaminated. I am sure every tank type has it's own quirks, and I know different model blazers have different tanks. I am surprised that the yellow Heet is not available in your area. Wal Mart stocks it here. The blazer is running great but I will add one Heet to every fill up for at least a while. I can only hope that when it happens again, and it probably will, I will have a better starting point to solve it much quicker. Good luck with yours!