Ok, going to make this as short and sweet as possible instead of going too in depth...

Here's my issue...

Had BDC out here 2 weeks ago to tune my car, looked everything over and all looked good. He started to do some street tuning and it would go lean into boost around 4500 - 5000 rpm at only 5 psi. So no matter how much fuel he threw at it, it would still go lean.

We pulled the fuel pump, check the wiring, then cut the hard pipe about 2 inches shorter and put fuel injection hose with clamps to make sure it was sealed properly. Did some more street tuning, same results.

Next we pulled the secondary injectors and made new grommets to make sure they seal correctly and checked the routing of all fuel lines...everything was good!

More street tuning, same results...

Lastly we put the car on a dyno so we could monitor fuel pressure, we suspected that maybe I had a fuel leak so to verify we checked the fuel pressure. Fuel pressure was steady at 55 psi while on the dyno, so that eliminated a fuel leak.

I'm at a loss here, anyone ever had this issue before???

Tuning with power fc w/ dataloggit
850 primaries, 1680 secondaries (bosch) w/ 10 watt, 10 ohm resistors
RP New Competition fuel pump
aeromotive fpr

The only thing I can think it may be is a faulty secondary injector...
resistors are messing up the signal
or wiring harness is jacked

Any suggestions would help greatly, need to get this beast tuned...I can give all mods if needed...

 

Sounds like secondary injectors are not coming on, should be apparent if you were datalogging the ECU inputs/outputs during these runs.

You can confirm the injectors are good by applying voltage across them and confiming they click. The resistors should be able to be checked with a multi-meter. Since you had to cut into the injector harnes you might want to check that the modified wiring is sound by shooting exch side of the circuit from the ECU. Otherwise the injector drivers on the ECU may be fried.

 

shooting each side of the circuit from the ECU, how do you do that? As for the datalogging the ecu inputs/outputs, I will ask BDC...

 

I agree - check your injector duty cycle while under boost. If you're hitting 90%+ at 5psi, your secondaries are probably not coming on. At injectors that size and low boost you should be pretty damn low on the duty cycle.

 

Just check the wire from the ECU to the injector and make sure you get continuity.

On the datalog, check to see if you are going lean when the log indicates that the secondaries are coming online.

 

Make sure one of the injector wires is not disconnected from the injector. I have seen this problem a few times.

Jason

 

another other gurus? also when we would boost any you could smell a very strong scent of fuel, yet we could find puddles or anything...I just replaced the FPD...

As for the other suggestions, I'm still waiting for BDC to get back to me on the datalogging...

 

Might not help, but still an idea. You should check to make sure your O2 sensor is working properly. If it's messed up it could be sending a signal to your ECM that your running lean, therefore on your FC it will always read lean. That could be why you keep smelling fuel though you always read lean.

 

hmm i think this is it, maybe you guru's can chime in...


put a smoke machine on the car, and smoke started billowing out of the LIM, after further investigation I was missing the outer bolt on the LIM that bolts it to the motor. Then on top of that found out that I was missing a block off plate to the split air pipe on the LIM... would this cause me to go lean no matter how much fuel we throw at it with 3 major leaks on the LIM??

 

Did this get resolved? If so, what was the issue?

 

Haven't had it fixed, this is what I think the issues is, we'll see...

Found out I was missing a bolt in the LIM, missing the split air block off plate, and the leak out the gasket! I have my other LIM getting polished, ordered new block off plates and already have the gasket, I'll post my findings in about 2 weeks...

 

i don't think it is related to injectors not connected. It would just shut off the engine when on boost. If anything, I suspect it was related to injector time not set correctly.