K1ng0011

I got a set of injectors from ebay. I know that is not the best decision. I am looking to see if anyone might have the pulse width information for them to program in to the .bin file. I am running rich at the moment and want to verify that I have the pulse width information correct. They are 19lb bosch 3 injectors from what I can see. Maybe if the exact specs are not available something in the ballpark?

19# injectors
0-280-155-746
1275194

K1ng0011

Only thing I have been able to find for them is on this thread.

https://rennlist.com/forums/928-foru...mes-chart.html

ULTM8Z

If you're referring to the voltage offsets, I can give you what I put into my friends car. I'll check the p/ns later today. Though he was having the opposite problem... running lean.

by "rich", what do you mean? Moderately low BLMs? Or BLMs so low that you're smelling raw fuel?

what year is your car?

K1ng0011

This is for a retrofit into an older camaro using a thridgen tpi setup. I just wanted to see if anyone had the voltage offsets for these injectors. I am not sure where to look for them. I looked everywhere on the internet that I could think of but I have not turned up anything. I figured maybe someone else might have used them at some point if I am lucky or might be able to locate a data sheet for these injectors.

ULTM8Z

Ok, but what year is the EFI system from?

K1ng0011

This is from a 165 maf ecu. From a 86-89 Camaro. Running ose12p bin.

ULTM8Z

Here's what I put into my friend's car..... Also (if your calibration has this) don't forget to zero out the low pulse width injector offset vs BPW table (a must with Bosch III's).

This table is for a 8D. if your table's battery voltage values don't quite line up with these, simply interpolate the values.

K1ng0011

On my bin the two tables that I have are the following for OSE12P. My understanding is that in 8D or OSE12P we are just changing the injector pusle width. Which is how long the injectors are open in ms. One of the following tables seems to be how long to pulse the injectors based on a specific battery voltage. The second one add-on vs injector pulse width I am not sure. My basic understanding is to lower the amount of fuel per pulse you need to lower the ms that the injector is open. So to reduce fuel I would need to lower the ms time.

Injector - Injector bias add-on vs Injector pulse width
Injector - Injector bias vs Battery Voltage

ULTM8Z

You're sort of correct... These aren't necessarily commanding the absolute pulsw width... they're more correction factors that are based on the type of injector you're running. These two tables, plus the injector flow rate constant are basically you telling the ECM what injectors are installed.

The injector vs battery voltage is to "correct" the pulse width (pw) for the battery voltage. I.e., for lower voltages, it's adding pw such that the injector is delivering the amount of fuel the ECM expects it to. It's really just characterizing the injectors so the ECM knows how to command them for various system voltages.

The injector bias add on vs pw is such that at low commanded pw's the old Multec injectors needed a little "help", so some additional pw is added when pw's are really low. The Bosch-III's are much better injectors, so that help is not needed, thus we zero out that table.

K1ng0011

Alright so to tell the ECU what injectors I have I would set the injector size, injector pw vs battery voltage, and Injector bias add-on vs Injector PW. Since these are bosch 3 injectors. I only need to work about the injector size and injector pw vs battery voltage. The person on the Porsche forum was using the following voltages and ms. From the 8D bin that you are using seems to have different settings VDC vs usec. I am not sure what usec is. Also from the 8D bin that you posted was that from the same type of injectors that I am using the 280-155-746?

volts
15.75 - .3438
14.81 - .3438
12.81 - .53
11.81 - .6653

ULTM8Z

The values I used in his bin were the same values I used in my bin. For my injectors, I had the exact Bosch data sheet for the injector p/n I'm running (which are 30 lb). After my struggles with injectors (you can search on my user name and Bosch-III's), I bought my particular injectors PRECISELY because I was able to locate the data sheet for them. I was sick of the guessing game with injectors...

Now, on my friend's car, we couldn't find the datasheet for his Bosch-III 19 lb injectors (which I don't recall the p/n on). So the next best thing was to try my settings. Fortunately they worked like a charm. He was suffering from BLM's in the 150-160 range (too lean). Putting in these values and zero-ing out the low-PW correction (in addition to setting the flow rate constant at 17 lb/hr IIRC) made the car run as good as factory again (it's a stock 305 TPI).

The usec is micro-seconds (millionths of a second). The table you're showing from the Porsche board is in milliseconds (thousanths of a second).

If you want to run the posted Porsche values, simply multiply the offset values by 1000 (i..e., .3438 becomes 343.8) before putting them into the TPI bin.

Also, since the battery voltages don't quite line up, you can get close. I.e., the Porsche 15.75V value would correspond to the 16.0V for TPI. The 14.81V Porsche value would correspond to the 14.4V TPI. And so on...

My guess is you'll get close enough with this approximation that even if you eventually found the correct values, the difference in performance you could feel would be negligible.

Assuming you had good 128 BLM's everywhere before the injector swap, your pass/fail criterion would be to look for a return to 128 BLMs.

K1ng0011

Thanks ULTM8Z. I think with the information you provided I will be able to make some educated guesses and get it in the ballpark now. I figured I would have found a datasheet by now if there was one. I also plan on making adjusting the injector size to get the AFR that I am looking for with my wideband.

ULTM8Z

That’s good you have a WB.

My friend’s car was bone stock and in good running condition prior to the swap. So once we got the BLM’s back to 128, we were safely able to assume that the WOT AFR’s were also back to normal (without having to actually measure with a WB).

On a car that’s modified and/or hasn’t been baselined prior to the injector swap, you want to be particularly careful about the AFR’s (especially when you’re finding the injectors are making your ECM trim the fuel richer (because it’s seeing a lean condition). Without a WB, you have no visibility on the WOT actual AFR, so it can get dangerous if you get too lean.