I'm sure they used a wideband while on the dyno.

-Alex

 

I should hope so! But nothing surprises me anymore.

 

I would suspect the injectors. Given that you've tried swapping ECUs and the problem persists, and that the car runs fine otherwise, and has a solid boost pattern, I can't see it being a control issue or a problem with the pressure regulator. Unless there's a leak that only occurs during the transition, it would seem that the injectors are allowing too much fuel in for some reason.

I suppose it's also possible that the ECU is getting an invalid input from a sensor, which could cause the problem to occur with all of the ECUs you have tried (all of which appear to be remapped factory units). However, it would then be strange that it runs fine before and after the transition.

 

The pump doesn't itself perform that function. The fuel pump relay provides battery voltage directly to the pump when the relay is closed, or through the fuel pump resistor when the relay is open. Replacing the pump won't change this. Regardless, the fuel pump relay should be closed at the point where he is running rich.

 

Well The Pump Is A 20b Pump Installed Last Summer At The Time Of Rebuild. And, The Inectors Are The Stockers, But I Had Marren Fuel Injection Put New Pental Caps And O-rings On Them And They Then Flowed And Matched Them. And Yes We Did Use A Wideband While On The Dyno, And I Did See With My Own Eyes That The Car Was Just Going Pig Rich Before Transition.... I Know That There Is A Possibility That It Is The Injectors, But I Watched Cam Bench Them In Front Of My Face. When Benching Injectors You Are Basically Checking For Resistance, What If I Have A Problem That Is While In The Vehicle Under Load?

 

If I Recall Correctly There Is A Resistor For The Fuel Pump And If You Eliminate That You Will Cause The Pump To Run At 9v At All Times. Hmmm, Wonder If I Should Try That?

 

Small correction to your statement:

If you eliminate the Resistor, the pump will run at 12V at all times (not 9).

 

It is possible to overrun the stock FPR (with an aftermarket fuel pump) and dump too much fuel. I'm not sure how much the 20B pump flows, but that's is a possibility.

 

is it possible that his primary injectors are getting stuck open? so right before transition when the secondarys are jumping in they are both putting fuel into the motor? causing it to run very rich? just a thought

 

Mahjik, Thing Is That I Have Seen Sooo Many People Run With My Setup Using The 20b Pump And Have No Problems. As We All Know The 20b Pump Is A Rec. Upgrade When Running Bpu's With Stock Injectors? Saxyman, The Resistor Is What Is Switching The Pump To 12v's If You Eliminate The Resistor You Will Run 9v Straight Through...

 

You don't need a new pump with the stock injectors. The FPR is what is setting the pressure (i.e. a 1:1 per manifold pressure). The only way that will change is if the fuel pump to too strong overruns the FPR. If not, your injectors are seeing the same "max" fuel as with the stock pump. Grant, there could be problems with the pump itself, but when working the injectors will see the same amount of fuel as with the stock pump as per the stock FPR.

 

Close, but not quite. The system uses the resistor to drop the voltage DOWN to 9V (at idle, and low engine loads). When you mash the gas and the pump needs to switch to high voltage, then the relay switches, and the system bypasses the resistor. This effectively raises the voltage to 12V.

-Rob

 

So Sorry, Been Awhile Since I Read That But Thanks For Clarifying That...

 

No problem. It's easy to mix things up like that. I do it all the time. Sorry I can't be more help with regards to your problem.

-Rob

 

Mahjik, So Why Then Is It So Recommended To Run An Upgraded Pump When You Have All The Bpu's? I Have Heard Of Alot Of Other People Who Are Not As Modded As I That Are Running An Upgraded Pump. Are You Saying That A 20b Pump Does Not Change The Fuel Rate Or Delivery On Our Cars?

 

Thing Is Cam Said That He Tested My Fuel System, He Said That The Rate And Capacity Were Right On The Money. So I Dont Believe It To Be The Pump...

 

Not through the stock FPR. The stock FPR is a 1:1, which means for every increase in manifold pressure, fuel pressure inceases the same. That rate/ratio doesn't change with the fuel pump unless the FPR cannot handle the amount of fuel coming from the pump.

An old way of bring more fuel into the engine was to use a Rising Rate FPR (RRFPR). You could set the ratio to 3:1 or something like to add more fuel.

 

I Guess Im Getting In Over My Head, Ratio's Make Me Dizzy.haha
Anywho Came Said That The Rate/ratio Was Spot On. I Believe He Told Me That For Every Pound Of Boost Increased The Fuel Should Increase 10psi. Or Something To That Extent, Do Not Quote Me On That, But Reguardless He Said That Scenario Was Rock Solid With No Fluctuations Throughout The Powerband Besides The "bad" Spot!

 

Anyone On Here Familiar Enough With The Pfc That I Might Be Able To Contact Over The Phone This Weekend As To Monitor What Specs Things Should Be At? I Will Be Borrowing A Friends Pfc To Hopefully Get An Idea As To What Is Going On, Hopefully!

 

It won't change pressure if the FPR isn't changed, but it has a bit higher max flow capacity. Not a whole lot, but it can flow more.

I run a "20B" pump, and I'm running a similar boost pattern. No transition problems for me. Regardless, I doubt it's the pump that's causing your problem.

 

Did the problem just suddenly appear or did you change something before that?

 

Clearly, if you're running rich momentarily, assuming you're not losing intake air somewhere, something is allowing more fuel in than it should be. That comes down to fuel pressure, injector duty, or a leak. I seriously doubt it's a leak.

If fuel pressure were too high during the transition, then the pressure regulator is the most likely culprit. However, it would seem strange that the engine runs fine otherwise. Unless the pressure regulator is being momentarily "overrun" like Mahjik said, the only way I could see that happening is if the regulator saw a boost spike at transition, causing it to increase fuel pressure until boost dropped back down. I suppose it's possible that boost spikes for an instant, but you don't see it on the boost guage. It would really help to have a fuel pressure reading at transition.

Otherwise, the injectors are not doing what they should be. As I said before, since you've tried swapping ECUs, I wouldn't suspect the ECU itself, but since you have only tried remapped factory ECUs, perhaps an input is getting screwy at that moment and causing the ECUs to react by increasing injector duty. With the PFC, you should be able to see if anything is out of whack.

Finally, you could eliminate the injectors as being the problem by simply swapping in another set. You're using stock injectors, so it wouldn't cost much to check, but I'd certainly do this after checking it out with the PFC.

 

Everything Ran Great Before My Rebuild, Then I Blew The Motor And Had Pineapple Rebuild It To My Specs. So I Figured That Since I Was Having A Problem After Rebuild That Mey Be It Was Something I Did During The Rebuild Process. Here Are The Things That I Upgraded During The Rebuild Process: 20b Pump, Flowed And Matched Injectors, Act 9.5 Lb. Flywheel, Rps Carbon-carbon Clutch, New Oil Injectors And Lines, New 99 Efini Turbo's (were Actually On The Previous Motor For About Two Weeks Before Motor Blew. I Think That Is Everything That I Changed During Rebuild....

 

Well you could try swapping the stock pump back in, and see if anything changes. Who knows? Maybe there's something funny about that pump.

Otherwise, my last post shows how I would approach the problem.