jetta code 1248

lee250

New member
Joined
May 11, 2010
Location
hawaii
TDI
2000 vw jetta
my jetta had code 1248 come on. when driving if you let of the gas for a second or two then step on it again it just seems like it wants to die and even seems like its downshifting as you slow down and starts blowing ALOT of smoke and one time it slowed down so much i had to pull off the road and come to a complete stop then it ran fine but still blew out the extra smoke for a while. other than when this happens it runs great.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
Do you mean "P1248-35-10" ?? Bentley lists this as a Injection Start Control Deviation…

That error indicates your diesel fuel injection pump is unable to control start of injection properly due to any of several causes. If you haven't changed your fuel filter recently it might make sense to do so, as too great a restriction in the intake line can cause this code. Do you have access to VCDS (new name for Vag-Com)... Does your VAG-COM show the fuel temperature to be in range? If not, this can cause this problem. Check the case pressure regulator valve next and then the resistance on the needle sensor on the third injector and between pins 9 and 10 on the pump harness. If either is out of range replace the part. Beyond that you will need to replace or rebuild the diesel fuel injection pump (just what you wanted to hear, I'm sure...)

Yuri

PS: could also be related to mechanical timing of the timing belt system to be substantially off... Have you checked or changed the timing belt recently ???
 

lee250

New member
Joined
May 11, 2010
Location
hawaii
TDI
2000 vw jetta
No I don't have access to VCDS. I don't know when the fuel filter was changed but it is a Fram so its not original. I just did the timing belt and it was running great till the car bottomed out and smashed the oil pan so it sat for atleast a month, probably more, waiting on a new pan, I live in hawaii and there was problems getting the pan. Then after the pan was done now all of a sudden it does this. And I didn't mention the jetta is a 2000
 

lee250

New member
Joined
May 11, 2010
Location
hawaii
TDI
2000 vw jetta
I'll change the filter but just to make a point the car runs excellent and boosts good and has lots of power it only has a problem after you let off the gas for a second or 2 and then step on it again. it does this uphill or downhill. It does have a hard time starting now to
 

wai-ho.lo

Well-known member
Joined
Apr 9, 2009
Location
Ottawa, ON
TDI
'03 VW Jetta TDI
I had the same problem too, loud knocking/clicking, loss of power (even worse than the already lowered the fuel injection quantity at its torque peak), rough idling... the timing was probably off by more than a tooth. I do not think the belt skipped a tooth as I just had the timing belt done. Here is the code:

17656 - Injection Start Regulation: Control Deviation
P1248 - 35-10 - - - Intermittent

I was in school so I just have the injection pump swapped, cost me about $800. I will check the fuel temperature sensor resistance. If it was the component that fried, I would have been able to fix my car by myself for less than $100 CAD. I will keep you updated!

cheers,

Wai
 

lee250

New member
Joined
May 11, 2010
Location
hawaii
TDI
2000 vw jetta
I changed the fuel filter today and test drove it and same problem. When it does it though if you shift into neutral and rev it a couple times then put it back in gear its fine till you start slowing again. It only does it slowing down, or coasting with foot off the pedal. any ideas other than change the pump
 

fyrsail

Veteran Member
Joined
Dec 8, 2007
Location
Indianapolis, IN
TDI
2011 DSG golf- wife stole it
Several things get these results, mine was the fuel temp sensor, and a pump head seal. These are easily changed by a child with moderate mechanical skill, and if you want the full pump rebuild can be performed for around 400 dallars if you have a little faith in yourself and some time to do a TB job at the same time. It takes me about 8 hours to rebuild a pump and do the tb job. If you want my daughter can walk you through it when she gets home from 1st grade for the summer. Also make sure to vacuum test your turbo as this can cause stuudderring like you describe also. hook up the vacum line to the turbo actuater and pull alittle vacum with the vehicle running, you should hear the turbo begin to spool up. also the turbo may be dirty and sticking open
 

sfierz

Veteran Member
Joined
Jan 21, 2001
Location
Rockford, Illinois
TDI
1996 Tornado Red Passat
Our 2000 NB auto has been getting this code off and on for a while. It seemed to start after a timing belt change but I don't know if that is exactly what caused it. We know the static timing is advanced somewhat, but what is funny is the car is running quite well and starting well in most cases. Before the belt change the timing was retarded and the car started horribly either when it was very cold (below 20F) or in the 50F to 60F range. Hot starting is fine. Now, cold starting is great but that same 50F range is weird. Could a fuel temp sensor cause this? I am seriously leaning toward replacing this sensor since the problem is so temperature dependant. I have replaced one in my B4 Passat and it helped quite a bit even though I had no code for it.
 
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