Fuel Pump, Car Stalls at Idle

[Vehi MK 11]

Hoping someone can help me out with my issue. The car ran great when I picked it up apart from a fairly heavy fuel smell coming from the engine bay (could not see any obvious leaks anywhere). Before bringing it into a shop I decided to replace the FPR, EGR gasket, and Injectors in that order (one at a time). The car ran fine after replacing the first two, but after replacing the injectors the car would stall after turning it on and letting it reach idle (it has no problems starting). I also noticed that the injector for cylinder 6 looked like it was flooding from the bottom of the injector, (where the injector meets the head). I replaced that injector but it would still flood once the car got to idle after startup. Also the fuel smell was still present. Out of options I towed the car to AAA to see if they could resolve the both the fuel smell and the stalling at idle issue. After a couple of days it looks like they found the source of the fuel smell, it was the fuel line running from the FPR that had a leak. They ended up replacing both the fuel line and the intake manifold gasket. However the stalling issue still persists. They then told me it was most likely either a bad fuel filter or fuel pump. I thought this was strange as the car ran fine before I started fiddling with the injectors, however as the car still could not run I told them to proceed with the fuel filter and fuel pump replacement. After trying 4 different fuel pumps, they called back to tell me that the VX needs 48-55 fuel pressure and that non of the 4 fuel pump they tried could produce anything above a 40 PSI. So they told me that the reason the car is starting but stalling is that its not getting enough fuel pressure.

Sorry for the long explanation but I tried to be as thorough as I could without writing a book haha. If any of the members here could lead me in the right direction it would be greatly appreciated because I am out of ideas, as AAA told me that they can't continue working on the car until I bring them a fuel pump that pushes out at 48-55 PSI. What fuel pumps have you guys used that gave you a good pressure reading.

Thanks

[Mile High VX]

Check out the group on Facebook too. More activity there and always lots of help.

Fuel Pressure spec is 43 - 55 PSI...not 48.

[Anita]

If you are looking for an OEM new pump, I am selling one.

I'm Anita, one of the long----------time owners who purchased their VX new back in 2000. I started picking up parts and pieces thinking about the day Isuzu parts would become scarce. I had a long love relationship with my truck and when my mechanic moved out of state I decided to sell the VX. Last year I passed it on to someone else. Now, I finally started selling all the surplus I have collected through the years.

I am selling a new, never been used, still sealed in its plastic Isuzu fuel pump $150

aprotich@glendale.edu
626 233-6076 [text]

anita

Thanks[/QUOTE]

[AZMusclecar]

maybe their fuel pressure gauge is wrong....

[Vehi MK 11]

So just to update you guys on whats been going on. I ended up finding a fuel pump from O Reilly's auto parts that had a fuel pressure rating of up to 80 PSI that was comparable with the VX. Took it to AAA. After about 4 days they finally got back to me and said that they are absolutely stumped. Their "ADVANCED LEVEL TECH" knows the car inside and out by now and can't seem to figure out whats wrong with the car. They also told me that they've been in contact with Isuzu and together are still unable to solve this unsolvable problem. They told me that my next best bet is to take my car to an Isuzu dealer and see if they would be willing to work on my car. However, as Isuzu no longer sells cars in the U.S. the dealer in question is essentially a Chevy dealer, which i'm sure would just be another hit and miss. I'm planning on just taking the car back home and putting in some more of my own elbow grease to try and get to the bottom of things. On the bright side, they tested/replaced several parts such as the fuel pump, fuel filter, FPR, fuel lines, intake gasket, etc. so my laundry list of things to do is possibly smaller. Luckily I'm only being charged for diagnosis haha. I'm sure I'll have more questions down the line so I'll make sure to post them back to this thread.

Also FYI, I finally got approved to join the facebook group, so I will definitely be on there as well. Happy to be part of the VX community and hopefully I can get my VX up and running soon!

[Mile High VX]

Certainly sounds like you'll need the collective wisdom of the group over there. I'm sure that someone else has experienced the same issue and can offer what the final solution was for them.

[WormGod]

Auto Pros of Aberdeen. These cats built one of the nastiest VXs out there from ground up with overboard modifications. Maybe reach out to them and pick their brains. Certainly wouldn't hurt at this point ya know.

Also, you said they installed a new fuel pump. Did they drop the entire rear to do it (the long but right way heh) or did they "dig a trench"?

[Vehi MK 11]

Quick update: as I got the car back from Triple AAA

Just to recap whats been done to the car.

What I did myself: 1. New FPR, 2. New EGR gasket, 3. New injectors
What Triple AAA did: 1. replaced a leaking return fuel line, 2. New intake manifold gasket, 3. New fuel filter
They also checked multiple fuel pumps, only able to get around 40 PSI. Eventually they just put the original Fuel Pump back into the car. (This was done by dropping the rear because there are no holes that I can see in the car haha). In my opinion, this is not a fuel pump related issue.

Good news is that fuel smell is completely gone. Bad news, car still doesn't run great, but runs better than it did. The car no longer stalls at idle, however studders quite bad under acceleration, and refuses to go past 3000 RPM's. Check engine light is also on, which Triple AAA told me was related to low fuel pressure.

Now that the VX is back home i'll go ahead and start troubleshooting and keep everyone posted. If anyone has any ideas feel free to share.

[Mile High VX]

What codes is it throwing if the CEL is on?

[WormGod]

From your current state, one thing it sounds familiar to is a bad EGR/line. I know you replaced the gasket, but what about the actual valve? Also, a clogged EGR line can give you similar issues. Clogged line and valve can choke out the engine with bad re-circulation mixture.

[Vehi MK 11]

I have heard about bad EGR/lines causing these issues. It'll definitely be one of the first things I try.

Here are the CEL codes that I got:

P0137: Oxygen Sensor Circuit Low Voltage Bank 1 Sensor 2

P0157: Oxygen Sensor Circuit Low Voltage Bank 2 Sensor 2

P0171: Bank 1 System Too Lean

P1171: Fuel System Lean During Acceleration

P0174: Bank 2 System Too Lean

Honestly, before I try anything I'm going to go ahead and reinstall my old injectors to see if maybe the new injectors are the problem. The car only started acting this way after I swapped out the injectors so maybe that will fix the issue. Hopefully will have an update by Saturday night.

[Mile High VX]

That sounds like the right place to start to me as well.

[a745035]

I have heard about bad EGR/lines causing these issues. It'll definitely be one of the first things I try.

Here are the CEL codes that I got:

P0137: Oxygen Sensor Circuit Low Voltage Bank 1 Sensor 2

P0157: Oxygen Sensor Circuit Low Voltage Bank 2 Sensor 2

P0171: Bank 1 System Too Lean

P1171: Fuel System Lean During Acceleration

P0174: Bank 2 System Too Lean

Honestly, before I try anything I'm going to go ahead and reinstall my old injectors to see if maybe the new injectors are the problem. The car only started acting this way after I swapped out the injectors so maybe that will fix the issue. Hopefully will have an update by Saturday night.

I'm getting the 3 codes below on my '01 Foxfire. (90,454 miles)

P0137: 02 Sensor Circuit Low voltage Bank 1 Sensor 2
P0157: 02 Sensor Circuit Low voltage Bank 2 Sensor 2
P1171: Primary Fuel Pump Insufficient/No Fuel Flow

I've replaced both aft 02 sensors and cleared codes, only to have all 3 return. Don't want to rush replacing the cats just yet but the deadline for emissions testing is coming up and I'm wondering if a lean condition (P1171) can CAUSE the downstream sensor codes? (seems unlikely that both would go bad at the same time.)

She starts, runs and accelerates fine. Visited a local muffler shop this morning and explained the scenario. The owner adamantly stated aftermarket 02 sensors are garbage, and that they must be OEM for this vehicle. (but I got the exact same codes as the original after the swapping them out.) I suspect there are different codes for NO communication with the computer vs. reporting LOW voltage, but I'm no expert. I'm going to change the fuel filter first and clear codes again to see if there's any change. If not, checking fuel pressure will be next. TIA for any other advice or suggestions.

[Mile High VX]

You can check with the Facebook group as well. Most of the VX family has moved over there and there is little traffic on this forum any more. Same great group and lots of knowledge and help over there.

[jimmyray]

did your issue get resolved? Soonds like an intermittant fuel pump issue