islingtonaudi

A few days back I bought a decent Craftsman digital multi-meter (Fluke was out of my budget...)and tested the rebuilt used injectors once again. All tested in the 16.1-16.2 ohms range, correct by what Bentley recommends.
Tested the stock injectors and they all tested around 17.5 ohms, high on their range but at least I knew that both sets were high-impedence injectors and should (theoretically) work.
I figured I'd try the smaller injectors again since now I have a couple thousand miles on the new manifold, got my CEL under control and have been getting decent mileage the past couple weeks with the stock injectors, about 21 mixed.
Today I drove the car to temp, let it cool off for an hour and swapped out the injectors.
This is an easy thing for anyone to do who can change spark plugs, having your injectors cleaned is a good thing every 100k I reckon.
When reinstalling them I definitely recommend to others that you should firmly seat them in the fuel rail bungs and then line them up in their injector holes on the manifold and tap lightly with a rubber mallet to seat them. New o-rings are a good thing!
Got everything hooked up and I frankly expected the car NOT to start but I'll be damned, it slowly came to life! It sputtered quite a bit and didn't want to idle very well the first couple minutes but slowly got better.
I drove it around the neighborhood a few miles and it definitely smoothed out. Checked for leaks, etc., and went out for a nice 30 mile drive with a combo of the freeway and some fast city driving.
The result: the car now runs great, doesn't seem to be down power at all and in fact, it seems to rev a bit faster now. Perhaps the new injectors are better matched flow-wise. The goal here is have a slightly lower flow rate, 149cc/min vs. 143cc/min for these new ones.
These cars run rich from the factory so my goal is to try to optimize my A/F mixture using an o-ring in the MAF and smaller injectors. I may even try higher fuel pressure at some point for better atomization. I know that my exhaust tips are a lot cleaner these days!
So why didn't they work when I did the manifold swap? I can only guess that it was too much for the ECU to adapt to initially. I got a CEL immediately when I got the car going a month back. Kept getting lean codes and only in the past 2 weeks have I gotten it under control by running an o-ring in my MAF and resetting my ECU.
By the way I need to thank 4audiQ for the tip on the injectors, he's been running these Bosch 0 280 150 715 injectors in his 90 for quite a while with a decent bump in mileage and good performance. I'll keep everyone posted but so far so good.

austinado16

Good news Doug. I'll be interested to see where your mileage goes now.

DaveInSaltLake

way to stick with it and reason it out!

AUDIMAN3

person were to replace one at a time, drive and let ECU adapt and then put another in etc, etc. I am interested in better mpg for sure. Of course you would have to spread cost of injectors out to see payback from initial cost.

islingtonaudi

Bosch, I listed them at the bottom of the post.

AUDIMAN3

I read like I listen to my wife sometimes.....

VAP

these injectors were so slow/sluggish to respond. Any/every time I've added new injectors they took an extra second or two to prime once ignition was turned on but then fired and smoothed out instantly, as if they'd been installed/running for years.

Oh well, what would life be without its little mysteries.

islingtonaudi

I dunno, I purposely reinstalled them on a warm engine so it would start easier. Seems fine now....

odelay12v

Boring!