So, I popped out to walmart tonight for a bag of dog food. Hopped in the truck, it fired right up, drove to walmart, went in grabbed the doggie chow and got right out, no line no wait, total time in store 5 mins, super smooth for a walmart visit. Hop back in the truck, go to start it and no dice. Engine cranks but with less oomph than normal, dash lights flicker or go out while trying to crank and battery light is on with key in the run position... **** i need a boost. So I call a buddy, no problem he's close by anyways. Just as he pulls into the parking lot the spot beside me on the passenger side opens up, more luck! nice and close to the battery. So we hook up the cables and let the battery charge for a few then give it a shot, less oomph than before, woops the headlights were on. So I take the keys and some guff for being mildly retarded and let it charge with everything off for another 10 mins or so while shooting the ****, then try to start it again and it turns over like it normally would but still won't catch and the battery light is still on with key in run even with his little volkswagen hooked up and running still. At the time i figured I'd flooded it or triggered the passlock thing or whatever it is with the voltage dips, so I get him to drop me home. I have some dinner and head back in my cobalt a few hours later to try again. Anyways, more boosting and messing around and still have the battery light and crank but no start (though the dash lights barely flicker now, trucks still there collecting shopping cart scars now while i think. I'm hoping I just had a crappy connection on the tiny little side post on the battery and was being impatient waiting on the charge, but looking for some more options.

I have an obd2 scanner and it shows no codes.
I can hear the fuel pump kick on when i put it in run, but havn't been able to do a pressure test yet.
I have no idea when the fuel filter was last changed(if ever) truck has 250,000kms only about 600 of em are mine.
I have no idea when the spark plugs were last changed (if ever), didn't check for spark, though I have 6 new plugs in the back I could've tested with (again, mildly retarded sometimes)
Checked the 3A and 50A IGN fuses both appear fine.

So, My Plan of attack for tomrrow after work:

a) try charging again for a while longer, hoping that crappy connection is not allowing enough amperage to charge quickly or start off the other cars battery and try to start.

B) disconnect, inspect and clean battery cables, and alt cables, then reconnect and try to start and/or jumpstart again.

C) yank a plug wire, pop in one of my spares, ground the plug housing with the jumper cable and test it on the frame for spark (hoping for nice blue)

d) put a shot of starter fluid in the intake and try to start

Hopefully one of these will get me back running, at least to get the truck home. Failing that I've got to wait until friday to start throwing money at the problem.

If I have to start spending cash, I want to spend as little as possible but still be able to get the job done properly. If for no or crappy spark, would get battery tested, new wires and swap to new plugs. If for no start with the starting fluid, fuel pressure gauge, fuel filter. Likely need all of these regardless as I don't know the PO or his maintenance habits.

So Here are my questions:
Am I on the right track?
Are there other tips/tricks/tests that are doable in a walmart parking lot for free?
Are there any other electrical connections I should check/cleanup?
Is there a better positive terminal to use than the crappy one on the side of the battery?

If you're still reading, thanks for stickng with me, and thanks in advance for any tips, tricks or advice.

 

You're definitely on the right track. Check fuel pressure to ensure that it's within spec and the engine is getting fuel. Check spark to make sure it's strong. Check all electrical connections between the battery, starter, alternator, and grounds. If all that checks out then do a compression test. If all of those tests are completed properly you should be able to find the issue and fix it.

 

Thanks Toby, going to go take a crack at it now.

 

well, that was fun. got there battery ws reading 9v.... didn't even know it'd go that low. charged er up and still no dice. so i shot some liquid fire in the intake and it caught and died.... booo fuel problem. So I picked up a fuel filter and got a tow home. I'm hoping just the filter is clogged since the truck ran fine until i parked it and turned it off. but with my luck the pump is toast anyways, great time to have a full tank of gas. So, in the interest of fixing this on the cheap, any tips on on changing the pump in the driveway? Was hoping it'd be possible to cut an access hatch from inside or get a buddy with freakishly thin arms so i don;t have to drop the tank.

 

Since it sounds like you've got a fuel pressure problem the next step is to get some hard numbers. Get a fuel pressure gauge, either by borrowing one from an auto parts store or by purchasing one of your own. If you're going to own a fuel-injected vehicle the fuel pressure tester is definitely your friend. You'll use it repeatedly in your life.

Check the fuel pressure. It should start at 60-66psi and stay above 55psi for at least ten minutes. Post back with the results and we can help you.

Before you consider cutting a hole in the floor of your Blazer to access the pump do some searching on the Forum and see others' reaction and experiences. From what I know of the subject I wouldn't consider doing it.

 

Why would you not do it? I did it, and I will not look back on it, and regret it one bit.

 

+1 on what Toby was saying. The fuel pressure needs to be between 60-66 PSI with the key on, engine off, and it needs to stay above 55 PSI for 10 minutes. If it doesn't hit these numbers the engine won't start. It's very sensitive to proper fuel pressure. If the pressure drops off too fast, then you have a leak somewhere. It may be the pump's check valve, or the fuel pressure regulator. Post up your numbers and then we can hopefully help you from there.

 

Fuel pump usually fails just after filling the tank...do not know why, but common.

Chances are the pump will still run, but not enough to fire the injectors, but enough to empty the tank.
My suggestion: disconnect fuel line at fuel filter, put a rubber fuel line on tank side fuel line and into a proper fuel container.
Locate the fuel pump test lead in the engine compartment, apply +12V to it from the battery and let the fuel pump empty the tank into the container. Also loosen the tank cap so the pump does not have to work against itself.

Then drop the tank and replace pump with a Delco unit only. Why go to all the trouble of cutting a hole in the floor for pump access?...highly likely the pump will only be replaced once...unless you really, really keep this Blazer for a long time.

 

Guys are pal has an electrical problem first.

I don't know if on these they will crank with the alternator disconnected but if they do charge the battery over-night disconnected. Make sure it has at least 12v. Hook it back up with the alternator disconnected. See what happens. If it runs shut it off, I don't know if these alternators are self exciting.

LT your going to have to spring for a cheap digital multi-meter

 

Trouble to cut the hole? I do not get the naysayers about that.
Lets say you have a half full or over half full tank of gas, rusty bolts down there ect, how long would it take do drop the tank, and get the fuel pump out?
Then, later down the road, when the pump fails again (because we know it will) you will have to go through all that again, when if you have the hole in the floor, you can just open it, pull the pump, have it done in literally 20 minutes tops.