#1 Injector Problem on a 1995 Jetta

My son has a 1995 Jetta. It's got a 4411 code (open or short on
Injector #1). We swapped injectors with #4 and the fault didn't move.
The wiring harness is good from the other side of the big round
connector to the injector. This is particularly irksome given that we
just replaced the MAF.

Anyway...are there any common problems that could cause this or any
time-saving ideas? (Next step is to excavate the ECU and check its
connections...can't believe they put it under the battery!)

JRE

ECU isn't under the battery but up near the cowl/wipers on right side.
Nothing common... but you need to do a wiring pin check from ECU to
injector.


"JRE" > wrote in message
...
> My son has a 1995 Jetta. It's got a 4411 code (open or short on Injector
> #1). We swapped injectors with #4 and the fault didn't move. The wiring
> harness is good from the other side of the big round connector to the
> injector. This is particularly irksome given that we just replaced the
> MAF.
>
> Anyway...are there any common problems that could cause this or any
> time-saving ideas? (Next step is to excavate the ECU and check its
> connections...can't believe they put it under the battery!)
>
> JRE

"JRE" > wrote in message
...
> My son has a 1995 Jetta. It's got a 4411 code (open or short on Injector
> #1). We swapped injectors with #4 and the fault didn't move. The wiring
> harness is good from the other side of the big round connector to the
> injector. This is particularly irksome given that we just replaced the
> MAF.
>
> Anyway...are there any common problems that could cause this or any
> time-saving ideas? (Next step is to excavate the ECU and check its
> connections...can't believe they put it under the battery!)
>
> JRE

FWIW I have a Mk2 GTI that also got this code off and on a few times about 7
years ago and since then it's never happened again (as if it fixed itself).
I just wrote it off as bad fuel or something

I worked on a 1997 Jetta 2.0 and it had some electrical gremlins like that.
I found that the main connection plug at the engine had some issues with
either corrosion and moisture. After I disconnected the plug, cleaned the
terminals and put some special grease on them................ no more
problems.
To take that connection apart you have to grasp it (engine side) so it does
not spin/twist while you twist the locking collar (transmission side). It
might make more sense when you examine it. Bentley did not seem to explain
this well, or I missed it somehow. lol

--

later,
dave
(One out of many daves)




"JRE" > wrote in message
...
> My son has a 1995 Jetta. It's got a 4411 code (open or short on Injector
> #1). We swapped injectors with #4 and the fault didn't move. The wiring
> harness is good from the other side of the big round connector to the
> injector. This is particularly irksome given that we just replaced the
> MAF.
>
> Anyway...are there any common problems that could cause this or any
> time-saving ideas? (Next step is to excavate the ECU and check its
> connections...can't believe they put it under the battery!)
>
> JRE

dave AKA vwdoc1 wrote:

> I worked on a 1997 Jetta 2.0 and it had some electrical gremlins like that.
> I found that the main connection plug at the engine had some issues with
> either corrosion and moisture. After I disconnected the plug, cleaned the
> terminals and put some special grease on them................ no more
> problems.
> To take that connection apart you have to grasp it (engine side) so it does
> not spin/twist while you twist the locking collar (transmission side). It
> might make more sense when you examine it. Bentley did not seem to explain
> this well, or I missed it somehow. lol
>

I'm pretty sure that's not the problem.

When the MAF went south we cleaned and reseated that connector before
buying its replacement.

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.

JRE

This is a problem with the Engine check light right? I forgot! lol

How did you "jumpered the #1 injector wiring around the connector"?

So has the injector been tested? Maybe you switched #1 injector with #3
injector?
Did you measure voltage at the injector? I usually will plug in a spare
injector to make sure that it clicks reliably.

NOTE: Resistance may change when a load is placed on the wiring.

AFAIK with the ross-tech.com scanner you can activate each injector
individually too. Makes testing them easier. ;-)

good luck!

later,
dave
(One out of many daves)



"JRE" > wrote in message
...
> dave AKA vwdoc1 wrote:
>
>> I worked on a 1997 Jetta 2.0 and it had some electrical gremlins like
>> that. I found that the main connection plug at the engine had some issues
>> with either corrosion and moisture. After I disconnected the plug,
>> cleaned the terminals and put some special grease on them................
>> no more problems.
>> To take that connection apart you have to grasp it (engine side) so it
>> does not spin/twist while you twist the locking collar (transmission
>> side). It might make more sense when you examine it. Bentley did not
>> seem to explain this well, or I missed it somehow. lol
>>
>
> I'm pretty sure that's not the problem.
>
> When the MAF went south we cleaned and reseated that connector before
> buying its replacement.
>
> 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.
>
> JRE

In article >, 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

Mark Randol wrote:

> In article >, 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

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


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?
And how do you know that it is #1 injector? blinkcode?
Try using a scanner tool and watching the injector firing or the misfiring
of that cylinder!

I have 'heard' about rails getting dirty.
I have replaced fuel pressure regulators in the 1988-1992 Jettas.
I have 'heard' about vacuum leaks killing 1-2 cylinders.
I have seen spark plug wires that short out at different times.

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

Interesting problem and I wish you luck!

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



"JRE" > wrote in message
...
> Mark Randol wrote:
>
>> In article >, 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

In article >, says...
> 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.

Wow! Sounds like you are on the right track. And a lot calmer than I'd
be by now!

If the connector to the ECU had corrosion to it, and this was from the
battery, the ECU May be toast. If you conclude ECU you may as well pop
it open and see if the crud got inside and is shorting stuff. Careful
about static and stuff, but anything going in a car should be reasonably
rugged.

You might look into a rebuilt ECU instead of a 'new' one. I found a
rebuilder for cruise control heads on eBay. The first one sent out was
also bad, but they took it back and sent my repaired one back. That
worked. Was MUCH cheaper than a ?new? unit from VW. I won't recommend
them, but if you want to know who it was I can probably look it up.
Shoot, I may have already posted it and you could find it in Google
Groups.

Mark
'95 Jetta GLS