rb20 running lean?

[nekoabandoned]

ok after rebuilding the motor and finally getting it in the car its running crazy lean.... any ideas?

[WhatsADSM]

You gotta be more specific? Lean all the time, lean under partial throttle, WOT, etc?

As a shot in the dark, did you remember to hookup the vacuum line to the FPR?

[nekoabandoned]

lean most of time , and yes haha.heres a better question, would the ecu not getting a rpm signal cause it to run lean? cause at the moment im not getting any voltage through pin7 ....the guy that i got the harness from did a real hack job on it, so ive been stuck running new wires all over the place. is there a chance that the signal wire the computer uses to convert the signal from the cas to the tach has been cut and could have been causing this issue ?thanks
Modified by nekoabandoned at 3:12 AM 6/17/2009

[Sil240]

How do you know your running lean?Where are you running lean?

Have you done a boost leak check?If No, then go do one.

You might have a leak at the ITM or a loose coupler/hose etc.

What fuel pump & fuel filter are you running?If they are stock (S chassis) change them out.

I have the same problem.2 D-bags did my wiring and now I've lost the signal from the #7 pin.

I bought this Dakota Digital box to convert the signal to my tach. (aftermarket)

[nekoabandoned]

oh and by the way , im running open elbow.... i dont know if that would mess with the o2 reading or not

[Carl H]

how do you know its lean?

ecu generates the tach output, it is not an input.

[nekoabandoned]

erm because i looked at the plugs and there super lean looking.. and theres absolutely no power , compression is perfect btw

[Carl H]

lol, that says nothing...these engines are setup to be somewhat lean burn unless in boost.stick a wideband on there and if you already havent upgrade the stock fuel pump to something of substance.check base timing as well...running lean is a blanket statement for an issue that hasnt been diagnosed.

[nekoabandoned]

ill see what i can do about getting a wideband , but ill check the timing first thing in the morning. thanks for the help so far

[nekoabandoned]

ok timing checks out and after getting a wideband i decided not to drive my car till this is fixed... its scary lean. after checking maf wires and going down a list of possibilities ive narrowed it down to either injectors or cas. i bought a safcII to see if it would help and didnt.. but i can make it die by adding fuel, any ideas?

i heard rb20 injectors and ka24e injectors are the same other than possibly 10cc difference, is this true?

can the cas going bad cause the engine to run lean?from my understanding the cas controls injector pulse and ignition timing.

please correct me if im wrong or if you guys have any ideas

[WhatsADSM]

What do the AFRs look like when cruising and at WOT?

Also there were 2 really good questions asked before which you didn't answer.:1) Did you verify that your fuel pressure regulator has a boost source connected to it.2) Did you replace the fuel pump with a high flow pump?

[nekoabandoned]

yes and yes, by all means it should be running a little rich if anything.

[nekoabandoned]

ok triple checked all my wiring , everything seems good ( all under .8 ohms) could the cas be s*** and the car still run? and could the tps be causing this? the safc is getting a good signal from the tps so i dont think thats it o.oalso ive been told there suposed to be washers between the upper timing cover cas and the cas bracket...i dont have those, could that be the problem?
Modified by nekoabandoned at 4:45 AM 6/28/2009