Fuel cut: TD05/Stock pump/550/revtronix/

[LucyFord]

Guys,

I just finished installing a TD05 in and took her out for the first run. Pulls hard up to ~5000RPM and then just falls flat on her face. My setup has the JECS MAF, STI 550 injectors, a revtronix stage 2 chip, BUT a stock pump. I am thinking the pump is maxed out. I have a walbro 255 laying around and plan to swap that in. But i am not 100% sure this is fuel cut? Where is the limit for fuel cut typically (g/rev or kpa or lb/hr)? Looking at my data it looks like at about 1.75 g/rev or 27lb/hr is where fuel cut happens but this is the reading from "(Stock MAF)" parameters and i dont have a stock MAF....

UPDATE:
Okay I have been reading about fuel cut on this forum. I thought i was just maxing out the pump but it sounds like there is a fuel cut caused in the code in the stock ECU to protect from over boosting cause by wategate failures by cutting fuel if boost exceeds ~14psi for ~3 seconds (or some function of load and time) and that you need a "fuel cut defender" to fix this. Weird thing is that i have seen 15-16psi of boost in this car before without issues, but maybe i didn't exceed the time.

So my real question now:

Do I need a FCD with a revtronix chip?

[Legacy777]

I would have thought the revtronix defeated the stock fuel cut or at least moved it up. Others that have experience with the revtronix will have the answer that.

The fuel cut is very very abrupt, is that what it feels like, or is it just you aren't getting any more power? Also, with fuel cut if you keep your foot in it, the rpms and boost will drop, come back up, hit fuel cut again, and so on. Like I said, it's very abrupt and when I've hit it before, it's quite unnerving. I've never kept my foot in it when it happens.

If this doesn't sound like what's happening then you may have a fuel issue or possible a turbo issue. Do you have a wideband that you are able to monitor AFR's with?

[wtdash]

HI,
90% sure the fuel cut was moved up by the Revtronix chip....I want to say 19psi, but searching on here should tell you. I didn't see it in a quick search of my old Revtronix emails.

You do not need an FCD.

If you're on the Revtronix (and NOT the Rob tuned EJ20G ECU) your boost should be set by the chip - 14 or 16.5. If you didn't, you need to give the chip a few miles 20 (?) and a few pulls to adjust. It should learn by itself......but you gotta give it time.

Copied from Revtronix manual:

ECU LEARNING
The ECU should be reset during the chip installation process.
As a safety feature, after reset the ECU will set spark timing to 75% of maximum. This will increase to 100% over time if no knock occurs. If knock does occur, spark timing will be reduced in steps. If spark timing is reduced to 25% of maximum, the ECU will enter a safety mode where fuel-ratio is enriched to 10-10.5:1 during full-throttle and the boost control solenoid is disabled.
Fuel correction learning is enabled in the Revtronix chips. This allows correction for varying engine condition, fuel quality and gasoline/alcohol blends.
Boost learning allows the ECU to adjust for engines and turbochargers of varying condition. If boost targets are exceeded under any condition, boost control solenoid settings will be reduced incrementally. If boost is below target for too long during full-throttle, boost control solenoid settings are increased. This is the only condition which will enable additive corrections to boost level.
Allow a few hours of light to medium throttle driving for the ECU to completely re-learn adjustment settings and reach maximum performance before applying heavy throttle..

FWIW, when I was playing w/different turbos while using the Rev chip I also tried a TD05 and it had a weird habit of when I 1st got on it (this was AFTER I'd given it time to 'learn') it would slightly overboost and then work normally. Mike @ Revtronix never was able to tune that out for me, but I ended up going back to the TD04 to eliminate the lag (I had this on my Automatic Turbo wagon) of the TD05.

P.s. I'd still install the Fuel Pump.

Td

[LucyFord]

HI,
90% sure the fuel cut was moved up by the Revtronix chip....I want to say 19psi, but searching on here should tell you. I didn't see it in a quick search of my old Revtronix emails.

You do not need an FCD.

If you're on the Revtronix (and NOT the Rob tuned EJ20G ECU) your boost should be set by the chip - 14 or 16.5. If you didn't, you need to give the chip a few miles 20 (?) and a few pulls to adjust. It should learn by itself......but you gotta give it time.

Copied from Revtronix manual:

ECU LEARNING
The ECU should be reset during the chip installation process.
As a safety feature, after reset the ECU will set spark timing to 75% of maximum. This will increase to 100% over time if no knock occurs. If knock does occur, spark timing will be reduced in steps. If spark timing is reduced to 25% of maximum, the ECU will enter a safety mode where fuel-ratio is enriched to 10-10.5:1 during full-throttle and the boost control solenoid is disabled.
Fuel correction learning is enabled in the Revtronix chips. This allows correction for varying engine condition, fuel quality and gasoline/alcohol blends.
Boost learning allows the ECU to adjust for engines and turbochargers of varying condition. If boost targets are exceeded under any condition, boost control solenoid settings will be reduced incrementally. If boost is below target for too long during full-throttle, boost control solenoid settings are increased. This is the only condition which will enable additive corrections to boost level.
Allow a few hours of light to medium throttle driving for the ECU to completely re-learn adjustment settings and reach maximum performance before applying heavy throttle..

FWIW, when I was playing w/different turbos while using the Rev chip I also tried a TD05 and it had a weird habit of when I 1st got on it (this was AFTER I'd given it time to 'learn') it would slightly overboost and then work normally. Mike @ Revtronix never was able to tune that out for me, but I ended up going back to the TD04 to eliminate the lag (I had this on my Automatic Turbo wagon) of the TD05.

P.s. I'd still install the Fuel Pump.

Td

Thanks, fuel pump is installed now but i haven't ran it. I will give it some more time to see if the problem clears up. Thanks for the quick reply i was already starting to track down parts for a FCD.

[Alphius]

The Revtronix chip does raise fuel cut. You do not need a FCD.

Td, my boost control can't accurately control my TD05 either. I have seen spikes up to 22-23 psi with the ECU controlling boost, accompanied by lots of knock counts. I just use a Hallman manual boost controller currently.

[wtdash]

I just use a Hallman manual boost controller currently.

I think Mike @ Revtronix was pretty convinced his programming could adequately control the higher levels of boost, but it appears that like the Rob Tuned EJ20G ECU (Rob recommends an MBC), it works best w/an MBC.

Thanks
Td

[BSOD2600]

I have seen spikes up to 22-23 psi with the ECU controlling boost, accompanied by lots of knock counts. I just use a Hallman manual boost controller currently.

I saw that too during data logging when the BCS was going in/out of safe mode....
http://bbs.legacycentral.org/viewtopic. ... 72#p314372

[LucyFord]

Boost selinode was hooked up wrong...

[Legacy777]

How so? The hoses were plugged into the wrong ports?

[LucyFord]

Yeah I had the tubes hooked up wrong. Had the bottom one and the side one backwards if i remember correctly. Runs great now.

[Legacy777]

Ok, good to know for others that may have a similar problem.