LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

Last season I couldnt tune or run my car worth a ----. Brand new motor at the end of the season and I never got a run out of it. No matter how much fuel I added in turboedit it would keep going lean in the upper rpms, like way lean.

The car is a 90 Crx Si, d16a6 forged internal motor, obd0, turboedit, gm 3 bar, dsm 450's, wideband 02 with digital readout.

I could add fuel and fuel and fuel while deep into boost (usually anything above 8psi I believe) and then it would start going lean, I maxed out the fuel maps, checked fuel pressure. Everything was fine.

I did a few nights of reading trying to find the problem, and came across a guy or two that apparently had the same prblem with never being able to get enough fuel. And 2 of them said that the removal of the fuel dampner on the end of the fuel rail could be the cause.

Im looking for a good answer or a good place to start so I can have a good solid season.

Thanks guys

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

fuel dampner does nothing. Sounds like you are maxing your fuel pump. Could be caused by a plugged fuel filter, line, pickup sock, or just not a big enough fuel pump.

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

I think your problem could be two fold you may be maxing out those 450's , and also if your running the stock fuel pump then you'll need a walbro 255.

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

If you use the wrong type of washer that goes on the fuel damper/banjo bolt, yes you will see the symptoms that you describe.
Ive personally worked on a car that had the wrong one installed. It behaved exactly as you describe.
It wasnt until we duct taped a FP gauge to the windshield, and ripped on it, that we figured it out.

Depending on the rail/damper/banjo you are using, some will use a washer that is serrareted on the inside diameter.

If you have access to a FP guage, and assuming this is your problem, your prerail pressure will be abnormally high, and will not decrease appropriately as manifold vacuum increases.

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

Was this on 8psi steady?

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

No this wasnt on 8 psi steady, this was on a built motor and it was still on it s way up to 18 or so psi

A few times I got there in 2nd gear pulls but the air fuels still got really lean and I would shift early, then in third they were just ridiculous.

The car has a walbro 255 pump, loud as hell, its new, its working.

I dont think Ive ever had the dampner off of this fuel rail so Im assuming its a stock washer

The onyl thing I really have changed in the fuel system is my fuel pump, new fuel filtere and a fuel pressure gauge mounted on the fuel return nut of the fuel filter

I have a liquid filled gauge I was planning on installing this year (was going to tap the rail) but I wouldnt be able to see it while driving

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

Figure it out?

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

no i need help bump

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

What is your wastegate set at? If you bosting to around 18 psi it's probably maxing out the DSM 450's.

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

I recently worked on a D16z6 that required exactly 19psi to max the ---- out of his 450's (Walbro pump on a stock FPR).
Id say your getting close to the end of the 450's, maybe.

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

There were 2-3 people on honda-tech that had these problems, all 3 fixed when they removed/changed that fuel dampener thing. One guy was like 350whp and maxing out huge (1000cc?) injectors. Took it off, and next dyno w/o tuning was like 458whp.

Re: LEAN! Fuel Pulsation Dampner - Could It Be Causing My Problems?
 

had this issue with OBD1 cars, they needed to ditch the low impedance injectors and resistor box. moment they went to high impedance injectors of the same size, instant resolution.

buddy had the same issue with OBD0, tried everything mentioned here, finally had to go OBD1 and high impedance injectors.