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View Full Version : Marine intake 4.3 $0D help needed



Airbrush guy
01-22-2020, 04:51 PM
Hi all, I've been tweaking the tune for a while now but still not entirely happy as seems hit n miss, I've change bin files, sa tables, ve table, injector times etc and only thing that not sure how to compensate for is the tb as was a cpi originally but now has marine tb which is supposed to be identical to 96+ astro. Does anyone have by a long shot a $0D that's tuned to use marine intake and injectors? My block is an l35 so has slightly better cam than 96 and running marine original injectors and 4bar fpr
Thanks in advance

Fast355
01-22-2020, 10:43 PM
Hi all, I've been tweaking the tune for a while now but still not entirely happy as seems hit n miss, I've change bin files, sa tables, ve table, injector times etc and only thing that not sure how to compensate for is the tb as was a cpi originally but now has marine tb which is supposed to be identical to 96+ astro. Does anyone have by a long shot a $0D that's tuned to use marine intake and injectors? My block is an l35 so has slightly better cam than 96 and running marine original injectors and 4bar fpr
Thanks in advance

I have done the L31 truck intake in the past starting with the 4.3 CPI tune setup. I moded the TBI memcal and bypassed the injector current sensing resistors.

Nothing really to change for the throttle body.

Just start tuning it via datalogs. Adjust the VE tables to give a BLM of 124. Adjust the AE to keep the INT around 128 on acceleration. Adjust the DE to keep the INT around 128 on throttle closing. Start with the L35 Astro van timing table. You could use the L35 Astro van shift tables and TCC tables for a starting point as well or keep the CPI ones. You can also build better shift tables using Blucats if you want.

I made an Excel file to directly copy the Blucats tables into and it converts directly to the TBI/CPI PCM tables. Made it all a Copy/Paste function. Made changing shift tables multiple times alot less labor intensive.

There is an Excel spreadsheet in the $OD file section that works well. I did alter the BLM target from 128 to 124 in the spreadsheet though. I prefer to keep the tune slightly rich and ket the PCM pull fuel as necessary via the O2 sensor.

dave w
01-23-2020, 02:19 AM
I don't have a tuned $OD 4.3 marine file to share.

I can help with $OD Wide Band O2 sensor (WBO2) tuning: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?5381-Wide-Band-O2-(WBO2-Tuning)-Spreadsheet

dave w

15041

15042

15043

Airbrush guy
01-23-2020, 05:03 AM
Thank you both that's shed more light on the tune. the motor is a v6 in the astro and have the injectors set batch as original , no done memcal mod as read that only applies to v8? Ill get a wideband next as seems more reliable than what I've been doing at he min I have a tweaked LT1 spark table and seems to run fairly well just not as well as hoped and forgot to mention I also run lpg so cts spark table set to add 2deg after changeover temp and pic of current injector offsets with pfi values in async and sync and only asked about tb as cpi was around 58mm and new tb is 90mm so assumed more air would throw values off?
15044
Thanks again

Fast355
01-23-2020, 05:41 AM
Thank you both that's shed more light on the tune. the motor is a v6 in the astro and have the injectors set batch as original , no done memcal mod as read that only applies to v8? Ill get a wideband next as seems more reliable than what I've been doing at he min I have a tweaked LT1 spark table and seems to run fairly well just not as well as hoped and forgot to mention I also run lpg so cts spark table set to add 2deg after changeover temp and pic of current injector offsets with pfi values in async and sync and only asked about tb as cpi was around 58mm and new tb is 90mm so assumed more air would throw values off?
15044
Thanks again

The marine TB should be about 75mm if it is a 3 bolt
Biggest thing it will change is the shift points vs engine torque and the line pressure vs engine torque. You are going to want to ramp the line pressure up more quickly especially in the low-mid TPS values.

Airbrush guy
01-23-2020, 11:53 AM
Thanks Fast355. not something I'd even thought of so will have a look and tinker a little, did you run the standard bosch marine injectors on your setup?