GM 4.3 No-Start - '01 GMC Jimmy Help

Hey All,

My niece's Jimmy won't start. Conditioned has degraded over the last 6 months and usually took about 10 minutes of cranking to get it started. Everything I'm reading online says check spark components first. I'm going down that road as the fuel pump is brand new. I'm trying to help her out while I'm here on vacation. Last night I replaced the gnarly cap and rotor and I put the correct nut on the stud to secure the intake elbow on the throttle body, actually seals now. Still no start. I'm thinking I'll just throw a crank position sensor and ignition module on it without troubleshooting. I really want to go to the beach today.

Their mechanic also replaced the intake manifold gasket last week to help remedy this condition(yes, I know. Pisses me off. Doesn't look like they did the work based on the sand and grit around the manifold but I digress). This mechanic is kind enough to add any work he does to their loan amount, buy here pay here slime. It was nearly paid off before the manifold gasket.

Using this link:

http://troubleshootmyvehicle.com/gm/4.3L-5.0L-5.7L/how-to-troubleshoot-a-no-start-1#1

Ignition module gets warm after cranking so I'm assuming it's getting a signal. Still may be bad I suppose.

Sounds like the fuel injection 'spider'. They make kits to put regular injectors in its place.

Thanks. I did read something about that but was trying the easy road first. Bought another code reader to see what the CEL is telling me before I start throwing money at it.

i know the fuel pump is new and all, but I'd still check fuel pressure.

3 Codes

P0171 Bank 1 System Too Lean

P0507 Idle Air Control System Revolutions Per Minute Higher Than Expected. This one logged twice.

Now smelling fuel while trying to start it, cranking strong, no fire.

I had an S10 with a 4.3 and the biggest issues leading to a no start/ hard start condition were:

1) cap and rotor- it was hard on them and they lasted 12k-15k.
2) IAC - motor would stick closed not allowing enough air in to start.
3) fuel pump check valve - fuel would bleed down overnight. It would take several brief tries cranking to build pressure and bleed air before it would fire in the morning.

I had the plenum gasket cause a rough idle, but not any starting issues.

Just to eliminate something simple, I'd remove the gas cap and listen for hissing and try starting with it off or loose in case the vent is stuck and the fuel pump is fighting vacuum.

How was it running before the no start issue? Any drop in mpg?

Thanks and we were just discussing idle air valve at parts store. Going to check it after I check for spark.

The two vehicle owners in question would likely never check mpg and my niece doesn't drive it enough to tell me how it was running yesterday.

Spray a little starting fluid in and see if it starts. If it does look at the fuel system. If it doesn't look at the ignition. Check the distributor these wear out. The drive gear or the shaft bushings.

buy here pay here place = anything could be wrong. they screw people over hard, so it could even be a non original junkyard lump that some bubba tossed in and missed some lines and hoses, but it ran enough to sell.

Gas cap off made no appreciable difference.

Plug out and it was bone dry. Looks like spark to me.

http://s13.photobucket.com/user/VWguyBruce/media/BDB214D4-1F3D-4A05-B8D9-F86E56505F7B_zpso4m94pp6.mp4.html

What's the gap on these plugs?!? I could fit a quarter in the gap on these things. Doesn't look fun at all getting the plug out behind the steering shaft.

dry plug and that nice spark = no fuel. spray some ether in it and see if it fires.

steering shaft plug is easy with a spark plug socket and a wrench on the hex end instead of a socket. i just put new heads on my mom's 96 the other day so i'm intimately familar with a 4.3 blazer engine bay.

how brand new is the pump and do you know it was actually done, per your intake gasket story? brand? my ebay special chinese pump in my truck is dying at 3 months and 300 miles.

It fires off when I spray into the throttle body.

Fuel pump replacement is entirely second-hand info from my niece's husband. I'm sure if they did do the job it was the cheapest part available. Looking at the top of the tank, I can see clean and shiny wires with fresh electrical tape. God only knows what they actually did.

There should be a schrader valve on the pressure line for the fuel injection by the back of the drivers side head so you can check for fuel.

Do you hear the pump running?
There's a fuel pump relay, mine was on the firewall, that could lead to a no fuel condition.

I don't recall if it was my s10 or full size that had a test lead tucked in the harness by the firewall for feeding power directly to fuel pump. Maybe some one else can confirm if there is a test lead.

Since it's been gradually getting worse, have you tried a fuel filter to see if it finally plugged up to the point that it won't run?

I could hear the pump loud and clear.

I just talked it over with them and they really need to talk to their E36 M3bag mechanic. I'm on vacation and don't want to mess with a fuel issue in a parking lot without my tools. Their air conditioning used to work before this guy did the intake manifold gasket too, I hate for them to take it back their but the guy has a certain amount responsibility for the work. It's only been 6 weeks.

i seem to remember these things require a surprisingly high amount of fuel pressure to function. Like if theyre down even 25% youre dead in the water..

Truck headed to the shop today. I'm curious to find out what they find.

So you guys know what it's like helping family and friends get back on the road. Throughout this ordeal my nieces husband has nearly insisted we try to get it started by jump starting it. It turns over just fine. I keep telling him it isn't going to do anything. He says the "race car mechanic" he works with at Goodwill says it will start if we jump start it. He can't tell him exactly why it will start just something about the brushes in the starter and bypassing the electrical system. I love my niece but it's getting old being told I'm wrong. Do you guys get the same kind of stuff, that every other armchair mechanic knows more than you? frustrating

It's the fuel pump. Shopping for one now on RockAuto. Shop was quoting $350-600 for a pump. Crazy.

What brand pump do you guys recommend?

VWguyBruce wrote: Truck headed to the shop today. I'm curious to find out what they find. So you guys know what it's like helping family and friends get back on the road. Throughout this ordeal my nieces husband has nearly insisted we try to get it started by jump starting it. It turns over just fine. I keep telling him it isn't going to do anything. He says the "race car mechanic" he works with at Goodwill says it will start if we jump start it. He can't tell him exactly why it will start just something about the brushes in the starter and bypassing the electrical system. I love my niece but it's getting old being told I'm wrong. Do you guys get the same kind of stuff, that every other armchair mechanic knows more than you? frustrating

Dealt with that before, it's the worst, especially when you can't really just tell the person to berkley off and fix it themselves.. Glad it got figured out, sorry you had to suffer through it.

I told my wife I didn't even want to order an $11 fuel filter that I would replace if it were our vehicle. Needed to check my intentions.

VWguyBruce wrote: It's the fuel pump. Shopping for one now on RockAuto. Shop was quoting $350-600 for a pump. Crazy. What brand pump do you guys recommend?

I'd go with the Delphi pump. Skip the cheapy stuff, you'll just be doing it again in 6 months.

Sounded like the fuel pump to me, these are notorious for needed very specific (and high) fuel pressure for the funky injector setup to work properly.

I know exactly what you mean about having a hard time helping people out when they can't help themselves but know better than you. Being raised with my dad turning wrenches for a living, I've seen it many times before so I try my best to keep an open mind and let the past be the past. However, recently my own GRANDMOTHER pushed me past the edge when I did her 30,000 mile service. She told everybody in my family that I did something wrong with the job because her fuel economy dropped...never said anything to me, I just had to hear it through the grapevine multiple times from multiple people that she went on and on about how I ruined her car. Long story short, in the end the car was fine (of course) and she never let family know that she was quick to accuse, never apologized, just forgot about it. I love Grandma, but I won't be working on her car anymore.

Good luck with the fuel pump fiasco.

Bryce

Stay away from Airtex pumps if you don't want to do that job again.

Good fuel pumps, Bosch, Delphi, Delco(one of the other 3 in a different box)or Denso. If you're seeing electrical tape, they probably went with the generic one size fits all, hack up the stock assembly pump. There's a reason its $40 and the real deal for said dirt common car is $150+.

I ended up buying a SPECTRA PREMIUM / COOLING DEPOT SP414M Fuel Pump for $128.99 which was listed as an SLS model only pump. It was outside the economy pump price range and had the little heart on it as a popular selling item on RockAuto. Has a 1 year warranty and the shop let me drop ship it to them. They ended up not even charging me for installing the fuel filter. All of these pumps come with new wiring harnesses and was why I saw some tape in there. As an added bonus, the air conditioning is now working again in the truck. Thanks to everyone who helped out with the troubleshooting.

Trying to enjoy last couple days of vacation while waiting on the HVAC guy to look at one of my mom's noisy roof vents. Never seems to end.