jcorenman

Fred, you are correct: 220 cc/min translates to a 21# injector. So 10% more fuel, which is within the LH adaptation range. The latency/dead-time is still the wild card, however. Either the 0.3 ms spec is correct and it is stupid-rich at idle/light-load, or the spec is wrong and we don't know where the fuel is at.

worf928

And could explain the reported poor at-idle performance.

FredR

Jim,

Our posts were ships that passed in the night!

i have no idea where the sizing convention comes from but given they are quoted in stupid British units one presumes they come from your side of the pond.

Calculating a nominal rating in lbs/hr is hit and miss as it depends on the SG used in the calculation- the refineries I have worked on invariably used a design SG of 0.77 for petrol but in practice there will be a range in real world terms and needless to say injectors pass a specific amount of volume- not mass. Somewhere in my files I have a link to a website that gives all kinds of flow data for injectors. Most Bosch injectors are based on a differential pressure of 43.5 psi but somewhat incredibly some are based on 36.25 psi which if I recall correctly can make a difference of circa 15%. Thus if a 19lb injector was rated for 36.25 psi and 43.5 psi was applied it would bump the design capacity up to about 22 lbs/hr. A crazy situation but not hard to see why so much confusion exists and that before one realises that for injectors without a Bosch part number one is really all at sea as it were.

I also thought the opening time stated was ridiculously low but have never researched such. Even though on my injectors I had the Bosch part number I could not find the opening time anywhere and stuck with that of the stock injectors [you may recall our discussion on this]- not a huge problem using ST2 but with stock programming I can visualise it being an issue. I know little about the adaption range as my motor runs open loop but given the cell range of adjustment we see in ST2 it seems reasonable that the stock system might handle the apparent discrepancy in the cruise map range- I have no idea what happens during idle and presumably on full throttle it will go even richer than the stock maps do.

marine928

Hi Fred. Just went over your reply. I sent my old injectors to osidetiger to be refurbished. They should get them today (Friday) or tomorrow. They will do their thing then run a comparison spec analysis to the injectors I received from them. This should answer any questions any of us have as to compatibility. Their website is osidetiger.net and they have several vids on youtube as well. I will send you the part number as soon as I remove one of the injectors later today. I could not discern the number from my pics.
Hopefully we can get some additional data that will help pinpoint any discrepancies and also assist osidetiger in the future.
Thanks for all your help.
Lon

marine928

Hi Worf,
Finally got back online and have time to respond to everyone's comments. I sent Fred a response and I will also check on the possible rust issue you mentioned. It's hard to imagine that osidetiger did not consider this and not apply some type of coating to prevent it. I did notice that the surging has decreased especially when I have the a/c on. It is still there, but only jumps 100-200 rpms vs the 200-500 I was initially experiencing.
Will keep you and everyone posted. see osidetiger.net
thanks,
Lon

marine928

Jim, just had time to get back online and respond to you, Fred and Worf. As you can see in my other responses, I sent my old injectors to osidetiger.net to be refurbished and tested. I also requested comparative analysis to the injectors they sent me. I will advise once everything is complete. A deep dive into tuning would be fun but would probably require additional modifications to the engine also. The only mod I have done is to drill out the CATs and have my ECU/LH rebuilt. Everything else is stock.
Thanks for all your great advice and I will keep you in the loop.
Lon

marine928

attached is the results when my mechanic sent my original injectors out locally in 2012.

FredR

Those were fairly clagged up.

When I first did mine many years ago they averaged about 5% down with a maximum of 10% on one injector.

worf928

Uh huh. That's what I thought too, the first time I saw injectors where the cleaning process removed the paint from the metal body. A couple of years later I got to do the job again under warranty because of rust.

Because when you hit the A/C button the LH computer 'knows' about it and adjusts the duty cycle of the ISV. In your case, since your injectors over-fuel at idle, the little bit of extra air from the ISV compensates just a bit.

Pay attention to Jim Corenman's post above.

soontobered84

I have not had "good luck" with the injectors that resemble Bosch injectors, but were actually Chinese knockoffs. Mine looked just like yours Marine. My car would NEVER run correctly with those injectors installed. I thought I was dealing with Bosch injectors since they looked so similar. Once I finally realized they were not Bosch, I changed to Bosch injectors and the car started and ran as it was supposed to.
Dave (Worf) and Jim are telling you that these injectors are wrong. Save yourself a lot of time and install the correct injectors.
YMMV

marine928

Actually I believe that these are Bosch refurbished. I did initially order a set of the C knock off's and they had plastic bodies and the o rings were incorrect. I sent them back and ordered the much more expensive injectors from OSIDE. They had metal bodies and the same numbering system as my original injectors. The only difference was the last three numbers. I should have taken a close up pic. I will be removing them and will get a pic then to attach. My old injectors were sent out to OSIDE for refurbishment and I will re-install them.
Thanks Lon

marine928

Worf, I did check with OSIDE re: polished metal body. They told me that they apply a non yellowing clear coating that prevents rust from ever forming. It has the same function that the original black coating. It is also mentioned in the FYI section on their home web page. They have never had an issue with it. They seem to be very confident in it.
Lon

marine928

Hi Jim, forgot to mention that the OSIDE injectors I believe are refurbished BOSCH. I do recall that all the numbers stamped into them were the same as mine EXCEPT for the last three. I will get a close up picture when I remove them and attach it. When you get a chance Can you give me a short primer on tuning. Maybe something along the lines of a minor tuning adjustment, cost and additional modifications I would need to make.
Thanks,
Lon

worf928

I looked at their website. Very cool. I will give them a try next time I have a set of injectors out.

http://www.osidetiger.net/service-faq.html

marine928

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