D Jetro basemap car will not idle, help? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Nizzy · 05-06-2019, 03:18 PM

Got a recently build SR20DET running Power FC D-jetro

Car will start every time, but after 2 seconds the injector duty cycle drops to zero and the car dies. If i pin the throttle to the ground it will rev for a quick second and then does the same. once started fuel pressure is a steady 43lb. Adjusting the fuel map changed nothing. Unplugging the MAP sensor has no effect. It's a redtop motor running what seems to be the correct red top SR20 ecu. Car is Borg Warner s252sx-e w/ 740cc injectors running the base-map tune given with the ECU. I'm using FC Datalogit.

My buddy is the one with the car currently at his shop but out collective knowledge on Power FC is pretty low and there's not many places to take it around Detroit who have a lot more knowledge. Figure it's gotta be something I'm missing that's right in front of me.

Thanks in advance for any help.

RB25GUY · 05-06-2019, 04:08 PM

Well unlike with the L jetro you have to literally start from scratch as far as timing tables fuel trims etc it wont start and run because there isnt reallly a basemap

RB25GUY · 05-06-2019, 04:10 PM

https://www.paulr33.com/powerfc-faq/powerfc-faq.htm#61

Kingtal0n · 05-08-2019, 05:00 PM

Well. There is a base map. The problem with the D-jetro is you need a Data-logit to access the base map. Its just how they are made.

All the commander can do is modify the multiplier of the base map. Percentages of whatever is in the true basemap.

If you had the data-logit I could send a file to upload to the computer, etc...
but without the data-logit, you are stuck dealing with the 'base multiplier map' with the commander...

FWIW L-Jetro (MAF) Unit does 450-480rwhp Using Z32 maf, and very reliable and fast/easy to tune (using only commander, no laptop).
I tuned one like two or three weeks in around 3 hours with 28psi of boost 450rwhp, including all daily driving map/fuel economy/etc
I've purchased an L-jetro PFC from Ebay before for $350 so this is usually my ECU of choice for sr20det setups.....

If I was forced to tune an D-jetro with no basemap, here is how I would tackle that
0. Setup the timing map (10 minutes)
1. use global injector constant to get the vehicle at first idle briefly, then cruising fairly well in the 14's and rolling into boost in the 12's (10~ minutes or less)
2. modify the MAP 0-5v fuel table first to see how far off idle is from WOT (10~ minutes)
3. spot tune the idle map region/just off idle until injector delay tables are close (10 minutes)
4. GO back and forth between cruising and idle while playing with injector delay until the 0-5v MAP fuel table is within 10% of itself (no large changes) (10 minutes)
5. Now you can spot tune the idle, cruise, rolling into boost a little using the actual basemap (10 minutes)
6. Setup the final rows (5+psi boost) of the fuel table so that fueling increases as redline approaches, with extra fuel through peak torque (10 minutes)
7. Go WOT and use the 0-5v MAP fuel table to dial in acceptable WOT a/f ratio (10 minutes for each boost setting)
8. Set up as many boost breakpoints as possible (10psi, 15psi, 20psi, 7psi, adjust the rows so that it makes sense 10-30 minutes
9. back to cruise/idle for final touch ups 30 minutes
10. change plugs, compression test, boost pressure test, dyno tune 1-3 hours
11. Drive around for hours spot tuning the fuel map as the engine warms, cools, as it gets rained on, cold snapped, hot sunny days, etc... It will need adjustments for the next 20 hours of driving as conditions change
12. once satisfied turn on narrowband operation

I guess 10 hours is possible. But it might need me there for a couple cold starts to get the cold fuel table right. So usually when things cool down I often need to re-visit certain cars. Although PFC is so simple it rarely needs adjusting for cold situations, honestly the factory settings are so close usually, plus intuition. You know what it is, its cheap injectors that need the most baby sitting. A set of $120 injectors will run your tail in circles trying to get afterstart enrichment and cold start setup properly. Just use high quality injectors and it should be fine with that.

RB25GUY · 05-10-2019, 02:51 PM

Quote:

Originally Posted by Kingtal0n

Well. There is a base map. The problem with the D-jetro is you need a Data-logit to access the base map. Its just how they are made.

All the commander can do is modify the multiplier of the base map. Percentages of whatever is in the true basemap.

If you had the data-logit I could send a file to upload to the computer, etc...
but without the data-logit, you are stuck dealing with the 'base multiplier map' with the commander...

FWIW L-Jetro (MAF) Unit does 450-480rwhp Using Z32 maf, and very reliable and fast/easy to tune (using only commander, no laptop).
I tuned one like two or three weeks in around 3 hours with 28psi of boost 450rwhp, including all daily driving map/fuel economy/etc
I've purchased an L-jetro PFC from Ebay before for $350 so this is usually my ECU of choice for sr20det setups.....

If I was forced to tune an D-jetro with no basemap, here is how I would tackle that
0. Setup the timing map (10 minutes)
1. use global injector constant to get the vehicle at first idle briefly, then cruising fairly well in the 14's and rolling into boost in the 12's (10~ minutes or less)
2. modify the MAP 0-5v fuel table first to see how far off idle is from WOT (10~ minutes)
3. spot tune the idle map region/just off idle until injector delay tables are close (10 minutes)
4. GO back and forth between cruising and idle while playing with injector delay until the 0-5v MAP fuel table is within 10% of itself (no large changes) (10 minutes)
5. Now you can spot tune the idle, cruise, rolling into boost a little using the actual basemap (10 minutes)
6. Setup the final rows (5+psi boost) of the fuel table so that fueling increases as redline approaches, with extra fuel through peak torque (10 minutes)
7. Go WOT and use the 0-5v MAP fuel table to dial in acceptable WOT a/f ratio (10 minutes for each boost setting)
8. Set up as many boost breakpoints as possible (10psi, 15psi, 20psi, 7psi, adjust the rows so that it makes sense 10-30 minutes
9. back to cruise/idle for final touch ups 30 minutes
10. change plugs, compression test, boost pressure test, dyno tune 1-3 hours
11. Drive around for hours spot tuning the fuel map as the engine warms, cools, as it gets rained on, cold snapped, hot sunny days, etc... It will need adjustments for the next 20 hours of driving as conditions change
12. once satisfied turn on narrowband operation

I guess 10 hours is possible. But it might need me there for a couple cold starts to get the cold fuel table right. So usually when things cool down I often need to re-visit certain cars. Although PFC is so simple it rarely needs adjusting for cold situations, honestly the factory settings are so close usually, plus intuition. You know what it is, its cheap injectors that need the most baby sitting. A set of $120 injectors will run your tail in circles trying to get afterstart enrichment and cold start setup properly. Just use high quality injectors and it should be fine with that.

05-06-2019, 03:18 PM	#1
Nizzy Join Date: Aug 2008 Location: Home of the Hitsville Posts: 7 Trader Rating: (0) Feedback Score: 0 reviews	D Jetro basemap car will not idle, help? Got a recently build SR20DET running Power FC D-jetro Car will start every time, but after 2 seconds the injector duty cycle drops to zero and the car dies. If i pin the throttle to the ground it will rev for a quick second and then does the same. once started fuel pressure is a steady 43lb. Adjusting the fuel map changed nothing. Unplugging the MAP sensor has no effect. It's a redtop motor running what seems to be the correct red top SR20 ecu. Car is Borg Warner s252sx-e w/ 740cc injectors running the base-map tune given with the ECU. I'm using FC Datalogit. My buddy is the one with the car currently at his shop but out collective knowledge on Power FC is pretty low and there's not many places to take it around Detroit who have a lot more knowledge. Figure it's gotta be something I'm missing that's right in front of me. Thanks in advance for any help.

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05-08-2019, 05:00 PM	#4
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	Well. There is a base map. The problem with the D-jetro is you need a Data-logit to access the base map. Its just how they are made. All the commander can do is modify the multiplier of the base map. Percentages of whatever is in the true basemap. If you had the data-logit I could send a file to upload to the computer, etc... but without the data-logit, you are stuck dealing with the 'base multiplier map' with the commander... FWIW L-Jetro (MAF) Unit does 450-480rwhp Using Z32 maf, and very reliable and fast/easy to tune (using only commander, no laptop). I tuned one like two or three weeks in around 3 hours with 28psi of boost 450rwhp, including all daily driving map/fuel economy/etc I've purchased an L-jetro PFC from Ebay before for $350 so this is usually my ECU of choice for sr20det setups..... If I was forced to tune an D-jetro with no basemap, here is how I would tackle that 0. Setup the timing map (10 minutes) 1. use global injector constant to get the vehicle at first idle briefly, then cruising fairly well in the 14's and rolling into boost in the 12's (10~ minutes or less) 2. modify the MAP 0-5v fuel table first to see how far off idle is from WOT (10~ minutes) 3. spot tune the idle map region/just off idle until injector delay tables are close (10 minutes) 4. GO back and forth between cruising and idle while playing with injector delay until the 0-5v MAP fuel table is within 10% of itself (no large changes) (10 minutes) 5. Now you can spot tune the idle, cruise, rolling into boost a little using the actual basemap (10 minutes) 6. Setup the final rows (5+psi boost) of the fuel table so that fueling increases as redline approaches, with extra fuel through peak torque (10 minutes) 7. Go WOT and use the 0-5v MAP fuel table to dial in acceptable WOT a/f ratio (10 minutes for each boost setting) 8. Set up as many boost breakpoints as possible (10psi, 15psi, 20psi, 7psi, adjust the rows so that it makes sense 10-30 minutes 9. back to cruise/idle for final touch ups 30 minutes 10. change plugs, compression test, boost pressure test, dyno tune 1-3 hours 11. Drive around for hours spot tuning the fuel map as the engine warms, cools, as it gets rained on, cold snapped, hot sunny days, etc... It will need adjustments for the next 20 hours of driving as conditions change 12. once satisfied turn on narrowband operation I guess 10 hours is possible. But it might need me there for a couple cold starts to get the cold fuel table right. So usually when things cool down I often need to re-visit certain cars. Although PFC is so simple it rarely needs adjusting for cold situations, honestly the factory settings are so close usually, plus intuition. You know what it is, its cheap injectors that need the most baby sitting. A set of $120 injectors will run your tail in circles trying to get afterstart enrichment and cold start setup properly. Just use high quality injectors and it should be fine with that.