Troubleshooting B4 in Northwest Indiana

I posted earlier asking for help finding someone who has vagcom in the area.

HERE IS THAT THREAD

http://forums.tdiclub.com/showthread.php?t=308971

Now I am starting to dig into it,

Replaced fuel filter, eventually worked out all of the bubbles visible in the fuel line.

Replaced N75, does have a bit more pep. Still goes into limp mode after hard accell. I think the waste gate actuator may be sticking.

Replaced the MAP sensor inside the ECU, what a nightmare. Hope I don't eventually regret doing that, probably nothing wrong with the original one. Changed it based on the report from the shop that changed the TB, they said it had a code that indicated MAP sensor shorted to B+. Didn't seem to help with any of the symptoms I have described. Will have to scan for codes.

Disconnected the coolant temp sensor to keep glow plug relay on long enough to measure for voltage at harness. All 4 plugs on gp harness read 12v when gp relay is on.

Appears that I have 2 bad glow plugs, 2 read OK the other two read open (no continuity).

GP fault code should likely go away once the new GPs are installed.

The code for "shorted to B+" was probably a battery issue at some point. Did you have a dead battery in the recent past? Disconnected battery when the key was on?

Did you replace the hose that connects to the MAP? If not, do it. Also replace the one that connects on the other side of the ecu wall.

Bad gps Please give reading for all four. Good ones should show about .8 ohms. That is, somewhat less than 1 ohm.

GP fault goes away when cleared. Good gps' may just keep a new one away.

Replaced battery in December ... shop that did TB reported that code to me. They said it cleared using vagcom, but returned as soon as they turn on the ignition (before starting the car). Sounded believable ... need vagcom to scan now that I have done a couple things.

Hoses replaced a while ago, checked hose inside ecu.

Two glow plugs read very low resistance (using a DVM w/o a low range so I don't really know how low - < 2 ohms)

The other two read open

Probably going to change all four.

So your saying I won't have to use vagcom to clear GP code?

Read about testing the waste gate actuator - will try to move it using pressure side of mity - vac.

Used a different meter to measure GPs. This digital meter displays .2 ohms with probes shorted together ...

Two GPs measured open
One measured .7 ohms
One measured .6 ohms



Not really happy with my decision to replace the MAP sensor with the one from DigiKey. It work for now, but it may not be a really reliable repair.

Found a replacement MAP Sensor on german website - mtron.de

They make an assembly that replaces the oem bosch map sensor 0273003210 (250kPa). It uses a sensor that looks exactly like the one from DigiKey. They mount it on a small PCB and have three pins that solder directly into the ecu pcb.

But I can't figure out how to order from them and can'y get an email through to them.


Glow Plug info.


Bosch 80028 Duraterm Glow Plug

Bosch Duraterm Glow Plug is designed with a self-regulating system that reduces glow wait time by more than 50 percent and enhances engine performance. It includes a heating coil and a patented dual control regulating system which enables the glow plug to reach higher temperature. This glow plug is corrosion resistant as well as guarantees better fuel combustion and is backed by 3 year warranty.

With coolant sensor unplugged, GP light on for about 20 seconds - I heard a buzzing noise from my IP while testing the glow plugs. Buzzing noise stops when GPs time out.

What is that noise?

The gps that read infinite resistance are bad. Replacing them will NOT remove the cel - you need to clear it.

I don't know any reason for the ip to "buzz" while gps are on. That's a new one on me.

Good luck.