• Guest would you be interested in CUPRA or SEAT valve caps? let us know in the poll

  • Welcome to our new sponsor Lecatona, a brand dedicated to enhancing performance for VAG group sports cars, including SEAT, Audi, Volkswagen and Škoda. Specializing in High Pressure Fuel Pump (HPFP) upgrades.

Checking for vacuum leaks tomorrow

corradophil

Active Member
Sep 14, 2004
228
0
Essex
My car has developed the fault below, its a 1.8t DBW AUM engine which is basically the same as the AUQ fitted to Leon Cupras. I'm looking for common areas which cause these problems, so I can focus on them. Obviously I'm going to have to strip bits off and do visual inspections, but any tips from people who have solved this before would be great.;)

17544/P1136/004406 - Fuel Trim: Bank 1 (Add): System too Lean

Possible Solutions according to Ross-Tech's Wiki:

Check Mass Air Flow (MAF) Sensor - Brand new one fitted showing good g/s reading.

Check Fuel Pressure Regulator - Brand new vacuum hose fitted between manifold and FPR. How do I check the FPR?

Check Fuel Pump - If all else fails I'll look at this and change the fuel filter.

Check Intake/Exhaust System for Leaks - I'll check these over the weekend.

Check Secondary Air Injection for Leaks - Any tips on known places where leaks occur?

Check Vacuum Lines for Leaks - I've checked most of these including all the plumbing around the N249 etc, and the DV which is fine, can anyone suggest any known week spots to particularly look for?
 

corradophil

Active Member
Sep 14, 2004
228
0
Essex
Found the problem, this pipe connects directly to the inlet manifold, so will cause vacuum/boost leaks. I repaired it and now th engine runs very well.

Hoseleak001.jpg


The hose location (hose not fitted in photo)
Hoseleak005.jpg


Hoseleak006.jpg
 
Last edited:
Lecatona HPFP (High-pressure Fuel Pump Upgrades)