Help with injector replacement Rochester 17090304
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08-04-2022, 12:45 PM
#22
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Damn !!!!
I’d be leavin’ like this.
I’d be leavin’ like this.
Last edited by SB; 08-04-2022 at 12:51 PM.
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AllDodge (08-04-2022), cheech (08-04-2022), DrFeelgood (08-04-2022), Gimme Fuel (08-09-2022), Padraig (08-04-2022), stealthfever (08-06-2022), the deep (08-04-2022)
08-04-2022, 01:21 PM
#23
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I just typed a long post and its gone, damn.
heres condensed version of what I just wrote being nit disappeared:
a stock 500 tune has the voltage offset /aka latency or deadband at the FOLLOWING: (3bar)
10v-.954 MS yours 2.46
11v-.687 yours 2.0345
12v .504 yours 1.799
13v. .351 yours 1.516
14v. .252 yours 1.251
Thats ALOT of ms thats NOT going to be added for injector deadband/latency vs what it calls for, that wont really show on my injector machine either but basically needs 1+ms added in background at 13v to equal the oes assuming they flowed equal, Smitty
I typed this out in much greater detail and its gone, will add to it later but got to get back to work
heres condensed version of what I just wrote being nit disappeared:
a stock 500 tune has the voltage offset /aka latency or deadband at the FOLLOWING: (3bar)
10v-.954 MS yours 2.46
11v-.687 yours 2.0345
12v .504 yours 1.799
13v. .351 yours 1.516
14v. .252 yours 1.251
Thats ALOT of ms thats NOT going to be added for injector deadband/latency vs what it calls for, that wont really show on my injector machine either but basically needs 1+ms added in background at 13v to equal the oes assuming they flowed equal, Smitty
I typed this out in much greater detail and its gone, will add to it later but got to get back to work
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cheech (08-04-2022), underpsi68 (08-05-2022)
08-05-2022, 01:41 PM
#24
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So now that Im sitting here at computer eating lunch, Ill explain this latency/voltage bias a little better:
"What is injector off time?
It is the amount of time between the point where the ECU told the injector to open and then told it to close, where the injector was not actually open or was not flowing at its peak flow"
So, how this applys when somone changes injectors on a efi motor is THIS: If PW/ms (the amount of time ecm commands injector to be open, or time is triggers) it is say 1.5 milliseconds at 1500, 3 ms at 2000, 4.5 ms at 3500, 6.5 ms at 4200, 8.5 ms at 5000 etc. So, with the stock 500 tune, in background it ADDS .351 ms to that 8.5 at 5000 for example. The voltage bias offset on the bosches needs 1.516 , so the injector will flow like its got 7.3 ms instead of 8.5 since offset is still at .351, NOT 1.516. Mercruiser notoriously runs there tunes fat so most likely it will be ok , this is also assuming both injectrors actually flow equally at the same ms, maybe the bosches flow more , fwiw, Smitty
"What is injector off time?
It is the amount of time between the point where the ECU told the injector to open and then told it to close, where the injector was not actually open or was not flowing at its peak flow"
So, how this applys when somone changes injectors on a efi motor is THIS: If PW/ms (the amount of time ecm commands injector to be open, or time is triggers) it is say 1.5 milliseconds at 1500, 3 ms at 2000, 4.5 ms at 3500, 6.5 ms at 4200, 8.5 ms at 5000 etc. So, with the stock 500 tune, in background it ADDS .351 ms to that 8.5 at 5000 for example. The voltage bias offset on the bosches needs 1.516 , so the injector will flow like its got 7.3 ms instead of 8.5 since offset is still at .351, NOT 1.516. Mercruiser notoriously runs there tunes fat so most likely it will be ok , this is also assuming both injectrors actually flow equally at the same ms, maybe the bosches flow more , fwiw, Smitty
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08-06-2022, 01:19 PM
#25
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Watching to see the results, very interested in the outcome.
08-12-2022, 10:25 AM
#26
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WOw...just like Arctic I was logged in and wrote an extensive follow up and it was gone once I hit reply. Back button resulted in my text not being there...I don't have the patience to retype at the moment but stay tuned for a very positive write up from my experience. Hopefully I'll get it done tonight or Saturday. How's that teaser?
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SB (08-12-2022)
08-15-2022, 10:09 AM
#27
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OK, gang. Let's try this again. I"m going to copy my own post before I hit the Post button this time!
Thanks again for everyone commenting and helping...learned a lot. So I didn't want any downtime with the boat and didn't bug Arctic about driveby so I called my old buddy (old school) boat mechanic across the bay. He doesn't help me any more since we are a few miles apart. Of course he told me just to slap those new injectors in and run them but I told him your comments and he said he did have an "injector guy". My mechanic buddy is an Off Shore guy and current has a 70s Cig but again...a carb guy. I don’t think he has much injector experience beyond what his computers tell him.
So we got my new injectors to his injector guy and he checked them over night against the "matched set" spec sheet that the seller gave me as seen above. The injector guy said they were good but didn't provide me any output of his tests. I had to just take his word from him and he was talking through my mechanic buddy. The consensus between those two was not to overthink the project since I'm not running high performance boat…run them. They appear to be bosche and spec’d to my need.
So the new injectors went in and the boat is running sooooooo much better. I now have a smooth ideal, never stalls coming off planeand lower RPM feel like they are firing better as well as smoother feel to the engine at my cruising 2800-3200 RPMs.
I do still get a fuel smell every now and then at idle (often in the channel) that my wife doesn't smell but the kid does. I've checked all fuel lines, pumps, resouvour and I can physically see the injectors under the intake...nothing is leaking. Never a smell when the boat is sitting or prior to starting cold (or hot). It's either coming from the intake or exhaust while underway. I have wild theory what could be happening but won't hijack my own thread but maybe start another. Atleast once on the first day of the injectors there was a hard start after a 1 hour run and then letting the engine cool for an hour. By that I mean it doesn't start instantly but maybe took 5-7 sec for the engine to burn off some fuel in the intake...?
I still have a project next time I'm at the lake to change the oil and inspect for fuel. Level is right at the high level mark when cold and DOES NOT smell of fuel.
So...
I've been amazed that several of your high performance needs might be the same lowly injectors on my 7.4 Volvo Penta Gi engine prob at 310-330hp but if you have needs for the delphi/rochester 17090304 injectors that I had trouble finding for two boating seasons I can report that my eBay injectors have worked out just fine for two weekends and 10 hours of run time. The seller is out of Chicago and someone ago above posed his link. He was quick to answer and provided (as mentioned) an output test sheet of a matched set for $399
If there is any interest I'd be happy to pay Arctic at the end of the season to test out these injectors to see if they are holding up to the claim or if they have other testable values best suited for your high performance needs.
-Shawn
Lake Erie
Thanks again for everyone commenting and helping...learned a lot. So I didn't want any downtime with the boat and didn't bug Arctic about driveby so I called my old buddy (old school) boat mechanic across the bay. He doesn't help me any more since we are a few miles apart. Of course he told me just to slap those new injectors in and run them but I told him your comments and he said he did have an "injector guy". My mechanic buddy is an Off Shore guy and current has a 70s Cig but again...a carb guy. I don’t think he has much injector experience beyond what his computers tell him.
So we got my new injectors to his injector guy and he checked them over night against the "matched set" spec sheet that the seller gave me as seen above. The injector guy said they were good but didn't provide me any output of his tests. I had to just take his word from him and he was talking through my mechanic buddy. The consensus between those two was not to overthink the project since I'm not running high performance boat…run them. They appear to be bosche and spec’d to my need.
So the new injectors went in and the boat is running sooooooo much better. I now have a smooth ideal, never stalls coming off planeand lower RPM feel like they are firing better as well as smoother feel to the engine at my cruising 2800-3200 RPMs.
I do still get a fuel smell every now and then at idle (often in the channel) that my wife doesn't smell but the kid does. I've checked all fuel lines, pumps, resouvour and I can physically see the injectors under the intake...nothing is leaking. Never a smell when the boat is sitting or prior to starting cold (or hot). It's either coming from the intake or exhaust while underway. I have wild theory what could be happening but won't hijack my own thread but maybe start another. Atleast once on the first day of the injectors there was a hard start after a 1 hour run and then letting the engine cool for an hour. By that I mean it doesn't start instantly but maybe took 5-7 sec for the engine to burn off some fuel in the intake...?
I still have a project next time I'm at the lake to change the oil and inspect for fuel. Level is right at the high level mark when cold and DOES NOT smell of fuel.
So...
I've been amazed that several of your high performance needs might be the same lowly injectors on my 7.4 Volvo Penta Gi engine prob at 310-330hp but if you have needs for the delphi/rochester 17090304 injectors that I had trouble finding for two boating seasons I can report that my eBay injectors have worked out just fine for two weekends and 10 hours of run time. The seller is out of Chicago and someone ago above posed his link. He was quick to answer and provided (as mentioned) an output test sheet of a matched set for $399
If there is any interest I'd be happy to pay Arctic at the end of the season to test out these injectors to see if they are holding up to the claim or if they have other testable values best suited for your high performance needs.
-Shawn
Lake Erie
Last edited by carboncow; 08-15-2022 at 10:11 AM.
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articfriends (08-15-2022)
08-15-2022, 11:39 AM
#28
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cheech (08-15-2022)
08-16-2022, 02:23 PM
#29
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Im sure they are close, at static they will most likely be within 98%, its the part throttle settings where they may flow low or high. I bought 33, 34, 36 38 and 40 lb injectors from varios suppliers at one point trying to find a "match " to the oe injectors and although the 36 lbs were almost identical to the oes at static (100% flow, fully energized) they had different characteristics, flow rates at various rpms and settings that didnt match the oes. At that time I did NOT test the exact injectors you just purchased. Panther Geronimo, a member on here, was fixing a hurt 500 efi, melted a piston in hottest cylinder and sent me the injectors, although the injectors had some stuff carefully ground off them, a search on remaining numbers matched 36 lb Bosch automotive injectors, when I flow tested them against some average oe 500 injectors, they flowed a little different and did not match . When FU marine tuned this oin water, it needed some more fuel added to the tune in some ares and if I remember right some pulled out.
so my offer to you is at no charge I will flow and test 4 of them simultaneously against oems and give you the real world answer, it would be greta if they match close enough to be a viable injector to use as a replacement. I will also pay the return sh, etc and do it expediently. I see your near lake erie, would be a jaunt but I would even be willing to do it while you wait if you drive up.
so my offer to you is at no charge I will flow and test 4 of them simultaneously against oems and give you the real world answer, it would be greta if they match close enough to be a viable injector to use as a replacement. I will also pay the return sh, etc and do it expediently. I see your near lake erie, would be a jaunt but I would even be willing to do it while you wait if you drive up.
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articfriends (08-16-2022)
08-16-2022, 03:06 PM
#30
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Carbon,
An interesting read, if you haven't already.
496HO Down On Power
Send them to Smitty. Trust me.
Thanks. Brad.
(937)545
An interesting read, if you haven't already.
496HO Down On Power
Send them to Smitty. Trust me.
Thanks. Brad.
(937)545
