Re: #1 Injector Problem on a 1995 Jetta

Getting back to this after trips out of town, etc.

See below. This bug is still kicking my ***.

(I've been working on cars for a Long Time. I'm not used to this and I don't like it! Plus I want my winter beater back from my son.)

dave AKA vwdoc1 wrote:
OK code 4411 from the blinks.
I think a good scan tool could tell you more and might help you find the problem easier.
You could ask someone here for assistance with their scanner http://www.steve-hall.com/cgi-bin/VAG-Locator.pl

I sent a note to the nearest one. Maybe he'll bring it over and it will help. I read here:

(http://tech.bentleypublishers.com/thread.jspa?threadID=7805&tstart=0)

....that the ECU might need to be reset under some circumstances. Any clue whether that's true after a MAF replacement?

Please explain/clarify exactly what is happening.

The #1 injector fires at idle but not under a load huh? How did you tell that? blinkcode?

No, I can hear the injector fire using a stethescope. It sounds just like the other ones, nice and steady. (Also, we swapped #1 and #4 injectors early on and the code did not move.) If I remove the connector to that injector, the engine misses severely on that cylinder. It loses about the same RPM whether I pull #1 or #4.

And how do you know that it is #1 injector? blinkcode?

Yes. But at this point I think the 4411 code might mean misfire on #1 rather than really meaning open or short to #1 injector, which is what Chilton's says. Misfire opens up some more possibilities, so I swapped #1 and #4 spark plugs and put in new plug wires.

Try using a scanner tool and watching the injector firing or the misfiring of that cylinder!

I'd love to but mine is OBD-II and I'm not buying one just for this.

I have 'heard' about rails getting dirty.

Dirt in the rail would clog the injector, right? So swapping injectors should move the problem. It does not.

I have replaced fuel pressure regulators in the 1988-1992 Jettas.

Fuel pressure is 38psi at idle and under load. The Haynes manual says it should be 36. My guess is that 2 PSI high is either gauge error or insignificant.

I have 'heard' about vacuum leaks killing 1-2 cylinders.

Bleeding propane around all the gaskets has no effect on engine RPM.

I have seen spark plug wires that short out at different times.

They're new.

But I guess dealing with the 4411 blinkcode then the problem is electrical..........
I had to clean up the main engine wiring plug on a 1997 Jetta 2.0 that had mutiple running issues. I think it was due to the injectors not firing................. (MAYBE YOUR PROBLEM) hmmm but you bypassed this plug and ran wiring directly from the ECM to the #1 injector or did you only change the connector at the injector.

Both. The injector was jumpered directly to the wiring harness at the ECU with its original plug disconnected, and then the original plug was replaced.

The resistance of all the wires from injectors to ECU is identical through the connector. I took all the tape off the engine harness and the wires all look OK; no shorts there, not even intermittent ones. So if there is a short or open (and I'm not buying that based on what my DVM tells me), it's got to be between the big round connector and the ECU.

Ahhh clean that too anyway using electrical cleaner and make sure it's seal is there too.

Everything has been cleaned with electrical connection cleaner.


Interesting problem and I wish you luck!

Too interesting! Damn thing's still broken.

Additional info: The engine is down on power when driven. It feels like it's more than one misfiring cylinder. At some combinations of RPM and load, it "tries" to act normally for a half-second or so and then goes back to the failure mode. Not sure whether the vastly reduced power is due to a "limp home" mode.

Tomorrow I'll check #1's compression, the engine timing, and the valve lift on #1 cylinder.


later,
dave
(One out of many daves)
http://vwdoc1.tripod.com/



"JRE" <nothing@xxxxxxxxxxx> wrote in message news:NC7xh.638$TQ7.448@xxxxxxxxxxxxxxx

Mark Randol wrote:


In article <OEEwh.62$Yd.32@xxxxxxxxxxxx>, nothing@xxxxxxxxxxx says...


When this problem occurred, I measured the resistance from the ECU side of the connector to the #1 injector and then from the engine side to the other three injectors. It was the same for all four injectors. Then, just to be sure, I jumpered the #1 injector wiring around the connector. No help. That's why I said the harness was good from the injector to the other side of the big round connector in my OP.


You're not saying you checked for a short. That's checking for an open.

I haven't checked the wiring diagram, but if what I suspect is correct...

To check for a short, unplug both ends of the circuit, like you said you did before. Check for a connection between the wires in the harness that go to the injector. Another way to say it is, at one of the connectors measure the connection between the pins that plug into the injector. There shouldn't be one. If there is, that's a short. I'd guess any reading above 100kohm is ok, but above 1Mohm should be what you see. Crud in connectors can also cause shorts. Try to do this with the connectors in close to the same position they're in when operating. If the wires have rubbed or cracked in a certain place, changing their position may eliminate the short while you're measuring. You might have to put one end in position and check the other end, then put the just measured one in position and check the as yet unmeasured end.

Mark
'95 Jetta GLS

Not shorted. The resistance across the injectors from the signal wire to the common return wire is the same for all four at the connector. Sorry I wasn't clear before. But there was a slightly pushed-in female pin (on the ECU side of the connector) for the #1 injector wire.

My son found that the O-ring seal for the ECU was not correctly installed and there was lots of corrosion. He cleaned it out (with the proper cleaner and a soft brass wire brush) and reseated it...no help.

The wiring is jumpered around the connector for now from the ECU side of the connector to the injector (with the right gauge wire, soldered, insulated with heat shrink, taped to the original harness), the connector to the injector itself is now new, and it still fails.

We also swapped injectors and the problem does not move with the injector. So the components remaining are the wiring from the ECU to the ECU side of the big round plug and the ECU. Only thing left to do is measure the resistance from the plug to the ECU, but it's looking more and more like it must be the ECU...drat.

I should also mention that #1 injector does fire...at idle. But given any throttle or when the car is driven the engine is clearly not running on all four cylinders and the only code is 4411.

JRE



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