SOLVED: Need help with bogging and misfires, persistent P0171 & P0174 lean DTCs

[workingonit]

Originally Posted by andrewwynn

You can double/triple the glove...

The openings wouldn't stretch far enough, being medium size (as both my wife and I use them); maybe large size gloves might've worked (if doubled). I'm ordering the Bladder Adapter today, so the gloves won't be needed.

[andrewwynn]

Oh I must have had bigger gloves mine worked great


Sent from my iPhone using Tapatalk Pro

[Scott ZHP]

Originally Posted by andrewwynn

Oh I must have had bigger gloves mine worked great


Sent from my iPhone using Tapatalk Pro

Same; I buy L/XL in 6mil; stretch it over the MAF, cut off the pinky tip and stuff the smoke hose in it secured with a small zip tie.

Just looked at OP's MAF reading... 52kg/hr at idle?? I'd expect 11-16kg/hr.

[wpoll]

Originally Posted by Scott ZHP

... Just looked at OP's MAF reading... 52kg/hr at idle?? I'd expect 11-16kg/hr.

I think that was at "cruise". When he buttoned off it dropped pretty quickly to around 20kg/hr and still dropping....

[victell]

The fuel pressure readings are close enough to spec that I do not believe it is a factor. I don't think volume is to blame either because under wide open throttle there'd be a steady decline in pressure as the engine consumes more fuel than the system can supply. This is what happened when my e30 had a failing fuel pump; idle and cruise pressure would be fine but would drop 15-20 psi under load. Even at 15 psi below spec the e30 would run decently, just down on power. It doesn't make sense that the X5 would fall completely on its face with 50 psi fuel pressure at the rail. As far as the fuel pressure drop when the pump is shut off, this was because the tester fitting leaked the whole time the system was pressurized.

Vacuum leak(s) seem more likely now. There was a suggestion to have a shop run a smoke test but I am more confident in my efforts and attention in finding these leaks than our local indy shops. I have ordered a self-powered smoke machine that puts out an advertised 6L/min @ 19psi which is significantly better than the cobbled-together thing I borrowed earlier. I've also ordered replacement DISA O-rings from G.A.S.

Now to find an enclosed garage to work in or wait for a dead calm wind day - both rare in Hawaii. Will report back.

[victell]

Originally Posted by Scott ZHP

Just looked at OP's MAF reading... 52kg/hr at idle?? I'd expect 11-16kg/hr.

I didn't upload the whole video but yes MAF reading drops down to ~14 kgh at idle.

[andrewwynn]

You can use a big tarp over the hood to calm the wind for smoke testing. I've done similar when I had a 40' ladder on the roof worked perfectly to hold the top over my head but it's a thought vs. using a garage if you can't find one.

[80stech]

The fuel pressure should drop (to the regulator setting and then hold) when the pump stops because of the way the syphon jet system is plumbed in. As long as you are confident that the pressure will stay up under a full load (throttle and rpm) and you are not getting fooled by the gauge connection (happens more than you would think) then you can rule out the fuel system. It was the first thing that needed to be looked at especially since all the trouble started with work being done. Are codes coming back? is the bog and miss consistent ? An all of a sudden vacuum leak bad enough to cause that much trouble and not be obvious is a tougher sell for me. Maybe the CCV or brake booster ?? Have you driven with the maf disconnected (before starting engine) ?

[workingonit]

Originally Posted by andrewwynn

You can use a big tarp over the hood to calm the wind for smoke testing.... it's a thought vs. using a garage if you can't find one.

I've considered buying a portable shelter for working on my cars & trucks, four of which have to be left outside the 3-bay garage.


Presently, bay 1 (with a manual single roll-up door) holds my home-built camping trailer plus automotive equipment; bays 2 & 3 (together, sharing the big automatic electric roll-up door) hold home repair & yard-working tools & mowers on one side, the wife's Lexus in is the middle, and there are antiques & spare furniture (all covered) on the other side. That's why I haven't been able to put my X5 into the big spot, where the Lexus lives, yet.

I work on my vehicles outside in the wind (it's always windy, with sand & Oak tree debris tossed in), and I've tried using a 10x10 Ezy-Up canopy for covering a car when I've got it apart, sitting for more than a day on my work station (3.25 sheets of 4x8x 3/4" thick plywood, over a sand & gravel base).


That hardly works to keep the summer sun off, much less a light rain, and there's no effect on the wind. I worked on my wife's old Cobalt, off and on for three years (mystery brake problem), using up two canopies that were destroyed by heavy rains. I'd never leave another canopy up for long, as destruction is inevitable.

A stronger-built portable 12x20 garage shelter would've been better, especially with sidewalls blocking the wind. I'm still considering getting one, if I ever have another maintenance problem lasting for very long. I think the Lexus will get parked under the portable garage, since the feral cats might get into an open engine bay outside, but not a locked & sealed Lexus.

[andrewwynn]

We use a similar tent for our cook tent for our big annual family reunion. It would work well for car repair and you can take the canvas off when not needing just leave the tent poles up.