Help ! Fueling problem on uprated injectors!

shaunwil · February 20, 2009, 05:39:05 PM

Finally got the engine bay back together with the 850/1600 injectors. Got a slight weep on the FPR gauge, nothing too serious when stationary. Set the open to atmosphere level on the FPR to 40psi but was really struggling to get it to adjust at all !

Fired the car up and it fired up very quickly. Huge plume of bluely smoke out the back and my wideband showing its running ridiculously rich.

There is vacuum showing on the commander so the vac gauge is working.

I\'ve just swapped the air temp sensor over to a fast response one and that is showing correct temps on the commander.

I\'m getting 10% injector duty when the car tries to idle, does that sound right ?

The only thing I think I\'ve possibly done wrong is plumb the FPR in backwards. Can pressure come back up the return of a aeromotive FPR if plumbed backwards ? Would the gauge on the FPR show this up ?

I\'ve also fit an FJO injector driver on all 4 injectors, could this not be helping ?

The injectors where all brand new. They haven\'t been flowed. Have I missed a key bit of the process ? Shouldn\'t they come pre flowed if brand new ?

Any help would be greatly appreciated. I\'ve got to have it MOT\'d on Monday and this has got me worried !!!

Cheers in advance

Shaun

nikp · February 20, 2009, 05:46:27 PM

10% injector duty at idle sounds a bit high to me. I think mine runs about 6%.

shaunwil · February 20, 2009, 05:50:36 PM

I\'ve upper the injector size on the commander to 850 / 1500 but that hasn\'t made a difference.

Shaun

Prof · February 20, 2009, 06:05:55 PM

I would have thought idle injector duty on primaries is going to be less that 5% for 850\'s - and nothing on the secondaries.

Did you enter lag times for the injectors - sometimes called something else and it escapes me. :confused:

You left the water temp sensor off ? - that would make it run rich

shaunwil · February 20, 2009, 06:14:51 PM

Water temp was showing 14deg, air temp was showing 10deg.

I think the 10% reading is just for the primaries. I turned it up to 1000cc and it didn\'t make a blind difference !

Just been trying to check the plumbing and it seems to pan out ok.

Bottom hose originally went to the primary rail, top hose went in to the FPR built into the secondary rail.

Can I adjust stuff like that from the commander

Shaun

shaunwil · February 20, 2009, 06:15:46 PM

I\'ve plugged the fuel temp sensor in but couldn\'t find the adjustment in the commander. Could this be the cause ??

Shaun

antnicuk · February 20, 2009, 07:38:12 PM

can you explain the plumbing again,

You should have a direct feed from the pump to the prim fuel rail, then out again to the secondary rail then out of the secondary rail at the end with the stock reg. It should then go to the side of the fuel reg, then out of the bottom of the reg should go back to the tank. The extra port on ours is blocked. (they are the same as yours)

gonzoninja · February 20, 2009, 09:09:46 PM

I thought also that the max you could change the injectors to using the commander was 1300cc, any higher and you need to use datalogit.

did you keep in the fuel temp sensor from the secondary rail? I know you were talking about a solution for that. Otherwise you would need to change that on the map

nikp · February 20, 2009, 09:18:23 PM

maximum size secondaries will go on commander is 1500cc. Higher than that and you need datalogit. However, at idle secondaries have no bearing on anything, they don\'t get used.

antnicuk · February 20, 2009, 09:18:30 PM

i eliminated the fuel sensor and didnt make any adjustments and it seemed fine. Also IIRC 1500cc or 1600cc is the biggest you can set the injector size to on the commander.

posted at the same time as NikP

SiH · February 20, 2009, 09:40:28 PM

Hang on dude, I think you\'re plumbing\'s wrong.

I can\'t see that well from the piccy but from your description...
If you are running the rails in series you should have flow from the pump to primary rail, then secondary, then FPR.

If you are running in parallel, as i think you are, you should have a line from the pump side of things which then splits with a feed to each rail. This each of the outlets from the rails should go into one of the side ports on the FPR.

The bottom port should then lead to the return line. It looks like you may have put the inlet from the fuel lines into the bottom port, which is the return.

antnicuk · February 20, 2009, 10:09:51 PM

thats what i thought but as you say its hard to see from the picture.

I would just run in series, much easier and works well even for huge power cars, also less likely to have leak with less joins

shaunwil · February 20, 2009, 10:27:32 PM

Its in series but the pickup for the lines is off the original hard lines that go under the Ignition coils.

Thought it didn\'t matter which line it goes through first ?? It goes into the secondary (from the front) then it goes through the primary then onto the FPR. One of the sides is blocked off and the return goes back to the hardline.

I think I need to adjust the PFC. Do I need to globally reduce the fueling table for the larger injectors. What does the injector size do in the injector menu ?

Cheers for the advise guys. Need to get it fixed !!!!

Shaun

shaunwil · February 20, 2009, 10:31:30 PM

Picture from the front :

Shaun

shaunwil · February 20, 2009, 10:51:49 PM

Been having a read about injector pulse timing which prof talked about :

http://www.clubrx.org/media/pfc/PowerFC_FD3S.pdf

I think I need to do some corrections !!

Need the Primary at 64.7% and secondaries at 78.1%.

Not sure what the lag time difference is though

??

Shaun