The car had a slight irregular miss at idle so I fugured it was time to purge.

It was relatively easy and I saw a lot of black crap floating around the pre filter.

Afterwards, the car seemed to idle a bit smoother/quieter, although the intermittent annoying low idle miss keeps hanging around.

Symptoms:

The idle drops somewhat and the car shakes slightly. Does not do it all the time. No fuel leaks to speak of. Changed both fuel filters also.

I think it's time for rebuilt injectors.

My indy is quoting me 350.00, for bosch rebuilts including labor.

He says the miss will go away and the car will be much quieter and much better performance.

Thoughts?

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Enough about me, how are you doing?

Have you done a compression test? It's possible that one cylinder is getting weak.

Never thought of it.

I figure that if it were something like a weak cylinder, it would be consistent.

This particular miss is very irregular and happens for no apparent reason.

I read an earlier post where someone mentioned the possibility of one injector not spraying fuel evenly would obviously casue a missfire.

I will probavly ask my indy to check it out a bit further before proceeding.

I'd hate to change the injectors and still have a miss.

Thoughts?

__________________
Enough about me, how are you doing?

Test the injectors for spray pattern and pop pressure. At the same time, do a compression test just so that you can check if off of the list of possibilities.

I assume I could take them to a diesel injection shop.

If so, what cost should expect for diagnosis?

__________________
Enough about me, how are you doing?

If you're going to do injectors, just get new ones. It may not be worth rebuilding them... Or test them all and replace the one that needs it.

I agree, have the injectors tested first. Chances are they just need to be manually cleaned, which is something a home mechanic can do.

BTW, I've come across this word "indy" several times on this board. Why do some people call their mechanics indies? What does it mean?

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

I think it's short for "independent", as opposed to a dealer mechanic.



I agree; be a good idea to have the injectors pop-tested and cleaned before replacing them...

Good luck!

I forgot too mentoin that the injectors that will be installed will be Bosch rebuilts.

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Enough about me, how are you doing?

I don’t know if it was a particular batch, or if Bosch’s subcontractor system was not working well at the time, but when I first got my 84 300D I installed two sets of “genuine bosch” rebuilt injectors and still had a problem. The supplier was really great, and he let me take two more rebuilt sets to a diesel injection repair shop to have them tested. Several had poor spray patterns, and the opening pressures were all over the map. I selected the best of the batch & installed them.

I don’t know if anyone else has experienced this, but “buyer beware”!


RTH

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Current rolling stock:
2001 E55 183,000+ Newest member of the fleet.
2002 E320 83,000 - The "cream-puff"!
1992 500E 217,000+
1995 E300D 412,000+
1998 E300D 155,000+
2001 E320 227,000+
2001 E320 Wagon, 177,000+

Prior MBZ’s:
1952 220 Cab A
1966 300SE
1971 280SE
1973 350SLC (euro)
1980 450SLC
1980 450SLC (#2)
1978 450SLC 5.0
1984 300D ~243,000 & fondly remembered
1993 500E - sorely missed.
1975 VW Scirocco w/ slightly de-tuned Super-Vee engine - Sold after 30+ years.

I have gone to two different shops in the past.
One was a truck shop with a manual tester and teh guy had to remember how to do the testing... reading as he went. They charged me for half an hour's time (35.00).
I then took a set to a Bosch shop in No California and they threw them on their tester, ten minutes later told me one was weak but not too bad and thanks for stopping bye. No charge...

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'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique

One of the problems that i've seen on a few TDI injectors is that they leak/piss a little fuel before they pop. If this happens, you will get a bit of black smoke and lower fuel economy. To test this, you need to bring the injector up to just below pop pressure, and observe.

Any diesel injection shop should have the equipment to test the injectors, and it should cost less than $100 to have all 6 tested.

Do the compression test while you have the injectors out, since you have to take out the injector(s) to test compression anyway. Kill two birds with one stone.

I sounds more like you have algea.
This will clog the tank screen and fuel
filters,and could account for the miss
at idle.

Louis.