Hey guys, I've got a problem that is totally stumping me. Problem started at the end of last year, put fuel in the car, which is a 2003 turbo, and on the way to storage the car started stumbling really badly, check engine light came on, and it barely made it back to the garage. I scanned the codes and it had two, one for a bank one o2 and another for a lean run on bank 1. I saw that quite. Few people said this could be a sign on a mass air flow going down. The car has sat for the winter, and today I first unplugged the mass air and the car would start but then stumble and cut out. I have an evoms intake on the car, and when I bought it used it came with a maf in it, but I kept the original on the car. I switched out the original for the maf that came with the intake and same thing, the car will start at high idle, but after about 8-10 seconds it chokes out. What could cause this? My first thought was possible bad gas but I've never seen bad cause a car to stall.... The day before we stored the car it had some pretty spirited miles put on it, but nothing unusual.... Sorry for the long post but I'm not sure what's causing this.... Boost/vacuum leak maybe? Any help would be much appreciated!

 

Does it start knocking before it shuts down? Fuel pump possibly.

Car will still idle and run with a boost leak.

 

Very possibly a boost/vacuum leak.

 

Could be a huge leak or hose off but also sounds like fuel. Feel free to call me Monday for some help. A line in the tank goes sometimes.

 

no knocking noise when it shuts off - car is extremely low miles, only has a hair over 11k miles on it, so it sits alot more then its driven.... i was thinking that maybe the fuel had too high of ethanol count but like i said its hard for me to believe that bad gas would cause it to stall like this...... once it stalls it fires right back up and again will just start to chug and choke out after about 8-10 seconds

 

It would be nice to know if you have fuel pressure. It can be your fuel pump at fault , loop hose ruptured....If you got access to a fuel pressure gauge plug it to the port next to the fuel filter....

 

agree with others. symptoms mirror fuel pump imminent failure. they often fail slowly as yours may be. it will start then die, and eventually not start at all. they are prone to failure ( what fp isn't ) and let's hope that's all t is. doesn't sound maf related at all. if you can start the car? then press the throttle and it dies? FP is toast.

check the f pump. first guess is best.

 

check for bad fuel pump and for ruptured fuel hoses off the fuel pump basket.

 

+1 i bet it is a hose in the tank/ pump basket split

 

Stock fuel pump assembly is pretty easy to remove and check. If you don't have a pressure tester let me know, I found one on Amazon that had the adapter for the fuel port in back that worked great.

When my pump failed it would run fine and then simply stop, leaving me stranded on the side of the road for ten minutes. Then it would fire up and go another few miles before stranding me again! I finally got it to do it when I had the tester with me and could hook it up fast enough for it to still not be starting, major pita!

 

Have to agree with others: On the surface it reads like a fuel supply problem. A repeat of what has been offered, but it bears repeating: The Turbo fuel system is rather complex and even if the fuel pump is ok a line can split or somehow leak and fuel delivery from the pump can be compromised.

As for bad gas, while I have driven a car, a new Infiniti, with "bad" gas (aka ~6 month gas), the engine started and idled just fine. The engine ran just fine, too, although the engine felt kind of flat. Not being familiar with the car I thought this normal until I ran the fuel level down enough I had to add fuel and with fresh gasoline the engine was transformed.

Still I have come upon one or two cases where the gas is bad enough to really cause the engine some grief. Rare though.

There can be another explanation especially if the car is allowed to sit long periods with no use. Mice can get at the car and chew lines and wiring and what have you and the car and engine can manifest all sorts of odd behavior accompanied by a CEL and one or more error codes.

I've see car and engine wiring harness damage, a vapor return line from the engine compartment to the tank chewed through -- the mouse stopped gnawing as soon as it got a snoot full of gasoline vapor -- carpet with bare spots -- the mice remove the fuzz for nest building -- the plastic tubes that carry air from the heater/AC and even the heavy rubber sheeting that makes up the radiator ducting.

Mice/rodent damage is rather easy to spot. One just has to give the car a thorough inspection with a bright flash light and possibly a mirror on a stick to be able to peer in the engine compartment at the harness. But often a telltale is mouse nest litter on top of the plastic panels under the car or mouse sign scattered about on top of the engine.

 

How long has it been sitting with the same gas? I wouldn't rule that out 100%.

 

Feel free to call me if you want to go over a checklist or anything I can do to help.

 

update: for those who said it was fuel/fuel pressure related you earned a gold star....
decided to drain the tank just in case it was bad gas and found a rubber hose on the fuel pump split so the car wasnt getting good fuel pressure. So it looks like it needs a new fuel pump.

Where is a good place to get a new pump? i noticed pelicanparts and vivid racing still sell the old style pump with the same rubber hose, does anyone sell an updated pump??

 

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