#1 Injector Problem on a 1995 Jetta

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.

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

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)

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

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)

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

So...did the last check before shelling out for an ECU ($100 locally from a junkyard)...and...the wire from the ECU plug to the big round plug is open. Guess we'll move that jumper later today. ;-)

The calmness comes from having worked as a computer tech (starting in the late 70's, when that meant using a 'scope) and a mechanic in prior lives. A step at a time, proving things as you go, always gets you there. Eventually. (Keeping the kid calm is another story.)

JRE

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

See below. This bug is still kicking my butt.

(I've been work> OK code 4411 from the blinks.

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

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

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.

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.

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

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

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.

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

They're new.

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.

Everything has been cleaned with electrical connection cleaner.

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.

Wouldn't the 4411 code be electrical? hmmm did you try switching the injector plugs to another injector? Put #1 plug on #2 injector to see if the codes change. I wonder if a bad cam sensor (distributor) could throw a 4411 code. Yep that vag-com scanner should help! Hopefully one with the tool will assist you! ;-)

Make me happy and clean the grounds at the engine and the body! ;-)

More replies inside.

Yeah ugly when there is a hidden problem or one hard to find. :-(

You will be pleased when YOU beat this problem! ;-)

wouldn't be a bad idea! New MAF? Correct one?

Unless for some reason the rail is clogged............very remote possibility though and I don't see how it could get clogged!

What if the FPR is leaking pass it's diaphram and into the vacuum hose? That "unmetered" fuel might be directed into #1 cylinder

Good but if the engine is running rich due to a fault FPR then the propane might not do anything. Now a rich mixture along with a vacuum leak might increase rpms, but might be adjusted by the ECM and the throttle body.

I still would not ASSuME! ;-)

hmmm did you try switching the injector plugs? Put #1 plug on #2 injector to see if the codes change.

Now how good is that Original ign coil? Maybe there are 2 problems!

luck! dave, (One out of many daves)

My son did this, and I did it again yesterday. The engine to negative post resistance was 0.2 ohms before and after.

Likewise...

Now *that's* something we need to check on.

Me, either.

Interesting idea, but the vacuum hose is dry. (I had it off to replace the spark plug wires.)

But if there is a fault in the FPR I would see it on the gauge. The FP is steady at between 37 and 39 PSI.

I'd hear (and likely see) the HV "snap" if they were shorting, particularly since they are not in the loom yet. If one were open, its cylinder would be completely dead and the engine would be very rough at idle. It's not.

Without rewiring them, you mean? Why? Aren't the injectors timed?

Once I decided that 441x might be a general misfire code, I checked. It throws a 1" spark without any problem at all.

OK more replies inside!

----- Original Message ----- From: "JRE"

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I have seen some with a dry looking vacuum hose. I usually watch the FPR with the hose off and the engine running. Sometimes I see a burp of fuel coming out and then it may stop leaking. USUALLY the clue for me is an engine idle change from down to back up again.

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That is good, but the burp could still be there. This is probably not your problem though, but I guess I would still check it along with checking the pressure increase with no vacuum at the FPR. ;-)

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Yes they should be timed and do this switch of the plugs without rewiring them. Just trying to find out if the same code will be thrown. The engine won't run correctly but if the same code is thrown I would look at the ECM and Wiring much closer. I know you did that many times and you are about to pull your hair out. :-)

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I guess if I was in your shoes I would purchase an imitation ross-tech.com scanner from ebay for under $30

try it out with the limited software to make sure it worked with your '95 Jetta. Then if it did work/connect, buy the software for $99 to allow you full use of it, but it will lock that software to that computer.BTW I think someone has a real one on ebay too which should allow you to use it on any computer that has the software! Of course remember that you can sell it after you finish using it or give it to the new owner of the Jetta! 8^) If you don't have a laptop then try to purchase one that you can extend with some CAT5 cable. Please note that some are USB and some are Serial. I prefer Serial connections and have 2 of the ross-tech scanners.

Here is one imitation scanner that would be under $17 including shipping

One day I may buy an imitation scanner to see how it performs since I already have the software! ;-) I am looking at one like this one that claims KKL but I would need a much longer Serial extension cable for it. I come up with crazy ideas from time to time. lol later, dave (One out of many daves)

Today, I continued to go "back to basics" assuming that the 4411 code means "#1 misfire" and not really "short or open #1 injector circuit" as Chilton's claims.

Compression was high and even (whew!) across the board. Spark plugs and wires (due anyway) were no help. Cap and rotor are nearly new. No evidence of arcing within but I cleaned the cap anyway.

On to check the engine timing, and surprise! It was off. At TDC, the OT mark was two teeth off. Pulled the lower timing cover and found the intermediate shaft timing off the same amount. Re-timed the engine and re-fired. MIL still on but it sounded so much happier that we decided to take a test drive. MIL became intermittent as the ECU re-mapped and then went out for good. Driveability improved by the minute as the ECU re-mapped more. In 100-200 miles, it will probably be back to normal.

My theory is that the mistimed Hall sensor led the ECU to detect a misfire, and caused the 4411. (That's my story and I'm stickin' to it.) This is not my first experience with an error in a service manual, but at least *this* time it wasn't incorrectly low head bolt torque.

We'll keep an eye on the engine timing and see what happens. There is nothing to indicate that it might have jumped; it's probably been mistimed for months, waiting for the "right" combination of temperature and air density to occur.

Also, just for completeness' sake...see below.

JRE

dave AKA vwdoc1 wrote:

The diaphram is OK. Honest! (We do have a spare FPR, BTW, but did not try it.)

I'll defer to someone with more VW experience than I have, but I must say that I find it unlikely that I'd see good regulation from a bad FPR. In my experience they have been either good or bad.

I didn't do this. Still don't see the point. I did everything except hook up an oscilloscope (I own two) to prove the wiring wasn't the problem. As it turned out, it wasn't.

I'll pass on this for now. But I'll keep it in mind.

Then I will say that the code was really for the camshaft sensor. hmmm could that code be the same for both the cam sensor and the #1 injector? I would have thought the cam sensor code would have been 2113 or 2114. I really prefer a scanner over blink codes. :-)

Big Congrats to you JRE!!! I am glad you stuck with it. ;-) I'll try to retain this info for future reference so thanks for the followup. later, dave (One out of many daves)