Broken down in Nebraska

RayBrubaker

Active member
Joined
Jan 4, 2001
Location
Waxhaw, NC USA
I loaned my '96 B4 wagon to a good friend and coworker to use while back from work overseas. While traveling in Nebraska it started to loose power on hills, run a bit rough, and set a code. AutoZone read the code as P1248. I made some suggestions of what to check and due. He cleaned the MAF and took it for a test drive, this is what he wrote: "It seemed like is was running smoother but if I had the throttle wide open it would accelerate well up to about 3800 rpm and top out. If I reduced the throttle position about 3/4 open or so then the car would accelerate to a higher rpm. I turned around and heading home the engine quit very smoothly. Not sure of the problem I checked for blown fuses. I can't start it now but the fuel lines all look full with no bubbles." He checked the timing belt, it is fine. On a recommendation from a friend at church he took it to "Precision Import Repair" in Kearney about six days ago, they have not been able to work on it yet.

Any suggestions of what might be the problem? He failed to check the fuel filter but that shouldn't cause a sudden shutdown. I fear an injector pump failure although I inspected the pump interior not long before loaning the car and it was clean without any evidence of making metal. Is an ECM failure likely?

Is the shop mentioned a good choice for the area?

I am overseas myself right now so handling this by email as I can.

Thanks for any help,

Ray
 

twentyeight

Veteran Member
Joined
Jul 14, 2009
Location
Phoenix, AZ
TDI
1Z & ALH
P1248 is start of injection timing regulation.

Timing is regulated by a valve allowing injection pump case pressure to modulate a piston inside the injection pump. The cause of this code is either no electrical connection to the N108 (unlikely) or lack of case pressure to actually move the piston where the ECU wants it.

I have had this exact situation happen before. Losing power when more fuel is needed and running rough is not "dying suddenly".

I would strongly suspect the fuel filter; it's cheap and easy to change (your friend can even do it himself) and it's preventative maintenance even if it doesn't solve the problem.

Be forewarned that priming the pump afterword can be difficult and take some time without an electric pump to help.

Good luck!
 

Bob S.

Top Post Dawg
Joined
Aug 17, 2006
Location
Central MD.
TDI
A B4V, some ALHs & BRMs
For field priming when in a bind, get a priming bulb (type used on boat outboard motors)(Wally world & NAPA usually have them) & a short section of fuel hose. Install the filter, & connect the hoses except the feed from the filter to IP, connect the hose, draw the prime (being careful to to spill D2 on materials I could damage), & connect the IP hose. I saves a long time cranking. I have one of these in each of my ALH road trip kit).
 
Last edited:

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I posted up in the NE chat thread that you were looking for info on Precision Import in Kearney and looking for some help on this. I posted to PM you if they had anything to add or contribute or knew some other place where the car ought to go for repairs.

Steve
 

RayBrubaker

Active member
Joined
Jan 4, 2001
Location
Waxhaw, NC USA
An update: at first the shop couldn't get any fuel through the filter so changed the filter then couldn't get fuel to the filter. I don't know what they did but the latest report from my friend using the car is: "They said they had tried a number of things and are now convinced that fuel is getting through the fuel filter but the pump is not sucking it in."

They had assured him that they work on TDIs so I would hope they know how to bleed the pump. They will work on it again Sat.

I'm overseas at the moment so working on this with a bit of a handicap.

Thanks for all the responses.

Ray
 

RayBrubaker

Active member
Joined
Jan 4, 2001
Location
Waxhaw, NC USA
The shop tried to prime the pump with an electric pump but still no sign of wanting to start. My friend needs to leave that area by Wed. so may need to ship the car home via a car carrier service. Any suggestions of which carrier services to use?

Ray
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I don't personally know of a shipping service, it's been almost two decades since I had a car shipped.

There are some online websites that can facilitate setting up shipping for various things. Uship might be one of those, can't really remember.

Steve
 

kooyajerms

grocery getter
Joined
May 5, 2004
Location
Pomona, Southern California
TDI
97 B4V (mine), 11 x5 35d (hers) 04 V10 (that one you want), 2014 Q7 (mom's) 74 Shasta 1400
It's probably too late to tell the shop this, but I wonder if they determined fuel was squirting by loosening all the injector nuts. That's usually the last step to losing prime, but when you see the mess of fuel, you're usually good to go.

Some times the fuel filter thermostatic tee o ring causes issue and lets air in too. But they said they work on TDI's *shrug* maybe they've tried all of this already.

Sorry about your (friend's) troubles.
 

RayBrubaker

Active member
Joined
Jan 4, 2001
Location
Waxhaw, NC USA
Up date and question

Thanks for all the help. The shop could not get it running after changing the fuel filter, the codes looked like IP problems. He shipped the car home. I pulled the cover off the pump and found quantity adjuster stuck, I have seen this once before on an engine that had set for a long time. I got the control head freed up but since I had it off I put on another one from a spare pump and got it running. I adjusted the IQ but after that it would idle well but wouldn't accelerate much past 2k and would blow a lot of white smoke. I hooked up an electric boost pump (from an '86 Vanagon) and it would run normal with the pump on but not with it off. It acted like the case was not being pressurized properly by the vane pump. I removed the pressure bypass valve next to the inlet to the pump and found it had come apart. I replaced it with another used one but it didn't run any better. I took the pump apart to replace what was needed (I have worked in these pumps before). The vane pump was worn considerable, replaced it with a good serviceable one. The pressure valve that I had replaced was again apart, put in a new one. Is it possible that the external boost pump could cause this valve to come apart? The camplate was starting to fret so put in a new one with rollers (this would not have been affecting the running yet).

After getting it back on and setting the IQ and timing properly it runs well with good power at lower RPM but gets a little rough and won't accelerate above about 3500 and will set a 0550 code. On VAGCOM it appears that the timing is not advancing properly to match the requested timing. I have a Log file but don't see a way to post it here. I replaced all the seals/O-rings in the pump and the advance piston was free. Any ideas on what this problem might be?

Thanks,

Ray
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
My understanding is these pumps don't like to see anymore than about 10psi from a lift pump. Unsure what the specs of your lift pump is.

I'd just spread the black retaining collar a bit and tap it back into the pressure regulator. I've seen some people go to the extreme and tack weld it.

I had a bad pump that used to throw the same 0550 code. Never really looked into it, I just swapped it.

Did you replace the advance solenoid? If bad, I read that timing stays pegged at 255, but that doesn't sound like your issue.

-Todd
 

RayBrubaker

Active member
Joined
Jan 4, 2001
Location
Waxhaw, NC USA
Thanks Todd, looks like we have the same cars in the garage, '96 B4V and '97 B4 (wife's), hope get my TDI Vanagon on the road again. The boost pump I used was from an injected Vanagon, it may be producing 60+psi. I didn't replace the advance solenoid since it was working, I should test it. Unfortunately I may have to go recover it again, the clutch has just failed. Its not slipping but suddenly won't disengage even though the pedal pressures feel the same.
 
Top