FRPP 80lb injector tuning problems

[WDW MKR]

FRPP 80lb injectors with latest SCT value file and 60psig base pressure. Running E85 with base stoick of 9.85. I scaled breakpoint, hi-slope and low-slope to match my existing tune.

It's gotta be something simple, but these things are kicking my ass. The car has run like crap since I installed them on Friday. I loaded the new tune, fired the car, then tried to keep it running while datalogging. The wideband showed lean, so I loaded a new tune with more fuel without much change. I then loaded a tune with less tune, based on the STFT showing rich when I'd hold the throttle up a bit past idle. That wouldn't even start the car. I went back to the other tune and took the car around the block. It took a lot of finesse to roll away from a stop without bucking all over the place and it didn't drive very smooth.

I built a new tune from scratch, loaded all of my typical personal and SCT value files, scaled appropriately and tried again. It ran better, but still the same deal of showing lean until it goes closed loop. The other problem is STFT1 and STFT2 showing a ~20% gap that wasn't there before. STFT1 would show near stoich while STFT2 was very lean. I swapped in a spare sensor and nothing changed. I then installed new Bosch sensors (yes, I know they're junk... no other option for troubleshooting on a Sunday) for both banks. This seemed to be the fix as both sensors took off and pegged lean. However, as they settled out, STFT2 was the first to come off 0.75 and float in the 0.80's. STFT1 then followed and went back to running near stoich. When I load a tune with ~10% more fuel, STFT2 then runs near stoich and STFT1 is in the 1.20s. This trend isn't always clean, but it's definitely a trend. The wideband matches the lean condition when STFT2 is showing it (wideband sensor in the driver side pipe).

It almost seems like I have an injector that's not firing or some other bank-specific issue. They are brand new FRPP units. I've unhooked and reconnected the harness without any change. I've eliminated the MAFia with no change (previously hooked up but set at "0"). I've tried different O2 sensors. I've verified harness connections at the MAF, IAC, TPS, FRPS, etc. I've tried a few different tuning strategies.

My previous combo was 75lb injectors with 93oct at stock base pressure and I didn't have any of these issues.

HELP!!

 

[GodStang]

Don't feel bad from what I have seen 95% of the tuners out there can not tune 80lbers.

 

[WDW MKR]

I used to hear the same, but recent cleaned up injector files seem to have changed that. It's a weird clash of opinions, though. Trusted tuners don't even agree... Eric Brooks says there are no tuning issues with the 80lb injectors, while Justin Starkey appears to hate them.

I cleaned the MAF. Found and tightened (2) loose charge piping clamps. Loaded various tunes and I think the problem is even worse. My last try was to load my previous 93oct tune with only the 80lb injector file loaded... stock pressure, now MAF Xfer tweaks, etc. Had to work the throttle to get the car to start and I now wreak of fuel. STFT split go worse and actually swapped banks with STFT1 bottoming out and holding 0.75 while STFT2 floated around 1.20... WTF?

I definitely think I'm better off starting with my new tune. I have a feeling my previous 75lb injector tune relied on a lot of MAF Xfer tweaks to accomodate for less than ideal injector data points. Could the new tune being crazy rich or crazy lean show errant O2 sensor readings? I've ran into that before, where it was so far off you just couldn't trust the data and had to keep working a a general direction until the car started and ran fairly smoothly before working the datalogs. Unfortunately, evertime I think I'm headed in the right direction the car still runs like crap and throws some other curveball at me.

 

[GodStang]

Sending you a PM.

 

[SVT GI]

Did you load the MAF and the injectors value files in the correct order? Force it into open loop and clean up the MAF xfer function. Should be no issues with the FRPP 80's values.

 

[rich5150]

FRPP 80lb injectors with latest SCT value file and 60psig base pressure. Running E85 with base stoick of 9.85. I scaled breakpoint, hi-slope and low-slope to match my existing tune.

It's gotta be something simple, but these things are kicking my ass. The car has run like crap since I installed them on Friday. I loaded the new tune, fired the car, then tried to keep it running while datalogging. The wideband showed lean, so I loaded a new tune with more fuel without much change. I then loaded a tune with less tune, based on the STFT showing rich when I'd hold the throttle up a bit past idle. That wouldn't even start the car. I went back to the other tune and took the car around the block. It took a lot of finesse to roll away from a stop without bucking all over the place and it didn't drive very smooth.

I built a new tune from scratch, loaded all of my typical personal and SCT value files, scaled appropriately and tried again. It ran better, but still the same deal of showing lean until it goes closed loop. The other problem is STFT1 and STFT2 showing a ~20% gap that wasn't there before. STFT1 would show near stoich while STFT2 was very lean. I swapped in a spare sensor and nothing changed. I then installed new Bosch sensors (yes, I know they're junk... no other option for troubleshooting on a Sunday) for both banks. This seemed to be the fix as both sensors took off and pegged lean. However, as they settled out, STFT2 was the first to come off 0.75 and float in the 0.80's. STFT1 then followed and went back to running near stoich. When I load a tune with ~10% more fuel, STFT2 then runs near stoich and STFT1 is in the 1.20s. This trend isn't always clean, but it's definitely a trend. The wideband matches the lean condition when STFT2 is showing it (wideband sensor in the driver side pipe).

It almost seems like I have an injector that's not firing or some other bank-specific issue. They are brand new FRPP units. I've unhooked and reconnected the harness without any change. I've eliminated the MAFia with no change (previously hooked up but set at "0"). I've tried different O2 sensors. I've verified harness connections at the MAF, IAC, TPS, FRPS, etc. I've tried a few different tuning strategies.

My previous combo was 75lb injectors with 93oct at stock base pressure and I didn't have any of these issues.

HELP!!

It's the .VAL file you probably have that is off. Some of the older-original value files that came out were incorrect. If you have the SCT Pro-Racer package, do an update and download the LATEST value-files.


[ame="http://www.sctflash.com/forum/showpost.php?p=73254&postcount=28"]http://http://www.sctflash.com/forum/showpost.php?p=73254&postcount=28[/ame]


ALSO make sure you load the INJ/Transfer function in the correct order as SVT GI said above.

 

[WDW MKR]

Thanks for the feedback. I should have both of the above issues covered (latest value file and loaded in correct order). It actually doesn't matter what order I load in, as my MAF Xfer (PMAS HPX in custom housing) is built and scaled in Excel before being loaded manually without a value file. I then scale everything manually. Still, I'll go back over my records when I get home and confirm that I haven't accidentally missed a scalar with the scaling. I'll also manually update the value files in Advantage, but I'm 99% positive they match the latest files I've found in other threads while searching for a solution.

I'm hoping it's something simple that I've just missed.

 

[AMB]

FRPP 80 Injector Files

The FRPP 80lb injector file ONLY works correctly for 05+ computers!!! It DOES'T work correctly for earlier computers, as per SCT!!!:fm:

 

[WDW MKR]

I replied to your post on SCT...

What data are we supposed to use, then? This is the first I've ever heard this statement. I also have a .pdf of the injector data from FRPP, but I think it matches the SCT value file. I'd have to verify.

 

[WDW MKR]

Actually drove the car around the block and got more data. The car definitely runs better, but it's far from the smooth running machine it was before the switch. It's a bit of a bucking bronco under some conditions.

I've made some more Xfer adjustments based on the datalog. We'll see what impact it has when I drive it, tomorrow. The STFT's are still doing some funny things and mainaining a split, though at least the split is reduced from yesterday and fairly consistent around 8-10%. AFR without adaptive enabled is a bit more cyclic than I'd like to see. Guess I'll just keep after it...

 

[AntiHeightPunk]

my tuner said the new 80's are one of the easiest injetectors to tune since they are OEM

 

[Swervedriver]

I just started this same thing. Installed 80 lbs injectors with a single bosch 044 at 40psi differential pressure at idle. Test ran it on 93 pump gase: It cranked right up, found stoich, cruised fine. Any boost would make it lean.

Replaced the pump with 2 "pro" 044 pumps, tank full of E85, set the Stoich AF in Advantage to 9.76: It cranked up but was rich. Just for the hell of it I tried setting the slope multipliers to 1 at all pressures above 39psi. It idled better and the STFT was 1.0x at light loads but tip in jumps lean, then goes rich, and tip out goes lean.

I had this same issue with my 60s when I tried cranking up the pressure to 60psi. I think the val files are tested at 39psi and the rest is just a quickly calculated guess...

 

[WDW MKR]

Just as an update, I yanked the 80s and installed ID1000's... piece of cake to tune and no issues like I had with the 80s. Not sure why I had so much difficulty, but I can use the extra headroom of the ID1000's with E85.

 

[Teej281]

Very nice man. My friend just got 80lb injectors from Tousley in, but is having his car tuned so the tuner will put up with the headache of tuning them and not him. Glad you got your issues sorted out. Too bad it took quite a bit more money than the 80's to fix it.

 

[04cobradude]

i love the 80s.. tuned close to 100cars with them and no issues

 

[Swervedriver]

Just as an update, I yanked the 80s and installed ID1000's... piece of cake to tune and no issues like I had with the 80s. Not sure why I had so much difficulty, but I can use the extra headroom of the ID1000's with E85.

Where you trying to tune the 80s at 40psi or higher?

i love the 80s.. tuned close to 100cars with them and no issues

Same question, are you able to use the val file slopes & multipliers at pressures above 40 or are you tuning them all at 40?

:beer:

 

[WDW MKR]

I tried various pressures, both for 93 and E85.

 

[AMB]

Wdw mkr

Did your ID1000's come with its own value files ??? :??:

 

[03Steve]

With a bank to bank variance in the 20% range, the flow rate of the injectors is suspect.

One example...

I had the 60s flowed on my combo before installing. There was a 12% variance from highest to lowest between the injectors. Here is my flow sheet (note before/after results):

With an engine at a 20% bank to bank imbalance, it's going to run poorly. A vacuum leak can cause that. An exhaust leak can cause that. If you force the car into open loop and it runs better...look for exhaust leaks. An improperly calibrated O2 Transport Delay can cause initial bank to bank variance in closed loop as well. Again...open loop can be used for checking there.

E85 and 9.xx stoich... I have done it on two cars now. If you have a perfectly calibrated gasoline combo, replace with true E85, and set stoich to 9.xx...the car is going to be rich. Why? Specific gravity of the fuel.

There are two schools of thought on this.

Greg Banish likes to adjust the stoich point until the he sees 1.00 lambda. You can do this in closed loop with the factory O2s and STFTs, or open loop with the wideband. The amount of correction required will be proportional to the ethanol content and the specific gravity. Don't be surprised if you wind up in the 11.xx range for a stoich point with true E85 using this method.

The second method involves adjustment of the low/high slope scalars. If you are flowing 80lb/hr of gasoline, and you swap to ethanol (which is heavier), the total weight of the fuel flowed through the injectors has increased. Ethanol is 11.25% heavier. That is your starting point on the slopes. That means those 80lb/hr injectors are closer to 89lb/hr injectors with E85. Remember...the bigger the numbers, the smaller the pulsewidth in the end calculation. Stoich is 9.xx in this method.

 

[cobracide]

I ALWAYS buy and highly recommend flow matched injectors. Good point above.