Guys/Gals,

I need desparate help. Installed BR 680 Injectors and walboro fuel pump. Car has erratic idle with -15 @ 800 on AFC (Buschur recomended) I tried adding fuel and removing fuel, the only way it calms down some is when I had it set with -5 @ 800. At that setting its still erratic, but not as severe. Something is not right. Please listen to the windows media file to aid in troubleshooting. Thx in advance.
http://www.jonesland.com/evo/engine.wmv

 

I got the same injectors and they sound the same, I am running 272's though. Are you running 264's?

 

Yes, I am running 264s but car was sounding like this before the cam install.

 

Oh wow before. Did you install the injectors and fuel pump before the sound aswell?

 

Bad idle came after installing injectors/pump. Only two changes that were made.

 

Still need help. Anyone?

 

Hmm... that video didn't help much for me because it sounded like the cam lope..

Do you have the ability to check your AFR?

At Idle, when the car is cold, it will run in open loop, then go into closed loop after its been running a bit. Once the ECU learns about the new injectors it might run a little better.

Now, with that said, it could be a severe misfire due to fouled plugs.. before you go too crazy, look for vacuum leaks, make sure the injectors are seated into the manifold well (as they probably are, but it can't hurt to double check) Then you might want to replace your plugs, at least remove them and check/re-gap them. If your plugs are original (Never checked/replaced yet) DEFINITELY Replace them anyway..

verify your fuel pressure is ok too.. RESET THE ECU if you haven't already.

To be honest, you should have done the pump upgrade first, verified all is well, and then put in the injectors a few days later.. just to be certain its not a fuel system problem.

If nothing is wrong, it may be the ECU trying to keep the mixture at 14.7:1 the only reason I say that is because at idle, "Stock" cars have 2% (At most) Injector duty cycle.. put a bigger injector in, and at 1 or 2% duty cycle, it could be getting a little too much fuel that cannot be adjusted out so the ECU swings back and forth and what you get is what sounds like a misfire or a Lopey idle.

Hopefully its a simple issue to fix.. Out of curiosity do you experience this before the car has warmed up? Does it go away after its warm? Was it smoother when it was cold, only to get rough like that when it warms up?

I can give you more insight after you can answer that stuff..

but here's the summary to check..

1) Check for leaks, and proper connections on the pump and its connectors
2) check to be certain the fuel injectors are seated in the manifold correctly and in the rail
3) make sure your Fuel Pressure Regulator is getting a good vacuum signal
4) check for other vacuum leaks, especially in the lines near the valve cover
5) Check for fouled plugs, clean or replace them.. gap them a bit tighter .026
6) RESET YOUR ECU if it hasn't been already.

Another suggestion with your S-AFC is to set your LO-TH setting to 0% tps so you can force the -15@800 (or whatever you need) to really "work" at that rpm.. if you can even it out at that point, you can raise the LO-TH point back to about 25%

With cams, you may always have a slightly rougher idle, but 264's with 0/0 timing offset should be fairly smooth and not sound like that.

Hope this helps.. I don't know too many people with upgraded injectors and I haven't installed my injectors yet.

 

I have 264/272 cams with the BR680 injectors. I'm running at 800 RPM -8% if I go above that car does not idel as well. At -8% I idel fine.

 

Thanks Malibu Jack,

I will check again for leaks. I ordered plugs last night after hearing of others with similar idle probs. I ordered the IW24. Figured it would not hurt much. When car warms up, its not as bad for a moment, then settles down into the erratic behavior. Has trouble starting from cold start. Have no exposure to cold weather as I have just installed these a couple of days ago. Need to stress that problem existed before cam isntall and did not get worse or better after the install. Buschur asked me to adjust idle screw as most of my problems are at idle.

 

I would turn the idle air bypass valve out a bit to raise the idle and give it a little more fuel. From what I have experienced my car sounds like that if i lean it out and get the AFR to lean. I have a wideband in the car so I can watch it and know he sound compared to the afr. I would say you need some more fuel and turn the idle up like i said. There is a recessed phillips on top of the throttle body. Back it out like half a turn or a little more and add maybe 5% of fuel and see what happens. I bet this will make it much better.

 

Tried adjusting idle bypass but it was a no go. I can get it to stumble a little less but at the cost of RPMs in 1100-1200 range.