:::RHMT::: Real Home Made Turbo

General Category => Engine Management => Topic started by: 92CXyD on August 20, 2010, 12:00:31 AM

Title: Fuel pressure issue (sorry about the text)
Post by: 92CXyD on August 20, 2010, 12:00:31 AM
Sorry about the long post but I'm making sure I don't miss any clues. ;D

Ok I just popped my third oem fuel pressure regulator. :-\

I started with a cdm walboro up in Wa. running at 45psi. all day no problem.

Then I build another motor due to my engine's need to eat crankshafts b/c of the shit oil pump. :-\

Went to start the car and the fuel pressure was at 23 psi. and dropping while engine ran like shit.

I notice I had some leaks from fuel rail inlet, fucked up pulse dampener and washer and I over tightened it.
The fuel rail inlet nipple thingy came out with the dampener that shit was all fucked up.

So I grab another fuel rail and I fucked up the tapping of the other side rail for the pressure gauge sender clound not use that on.

I finally get a fuel rail from my old CX setup that has no dampener with just the regular boring type cap and with the holes through the side of inlet nipple.

That helped get the pressure back up to 45psi.  ;D Thinking problem solved.

Then a week later (because I had a lot of things going on that week) I go out to start the car and it will not start.

Look at the pressure gauge and it is up to 60psi. So I burn a whole new map (Crome) with the higher pressure and it idled alright but ran like dog shit.

So I figure I needed a fuel filter, changed it, and it is still shit.

So I change the pressure regulator #1 to #2 and it worked. Great, thought problem solved. ;D

Go out the next day to start the car and I'm back above 60psi.

So I pull the pump and put in a used OEM one and the pressure looks good runs at a steady 50psi.

Then when I had started and stop the motor a few times the pressure is climbing back up to 100psi.

So I switch to another pump and the pressure stays at 100psi.

So I went and figured out that maybe the return line was clogged from some shaving from the fuel rail when I tapped the end for the pressure sender.
I blew out the return line, the rail, filter to the pump line. Put it all back together and still a no go.

So as a last ditch effort I  put a pressure regulator (#3) on and the pressure stayed at 45psi. I figured the first 2 pressure regulators were ruined from some Al shavings.

Then I went out to my car this evening and my car startup at first, then died.

I started it up again but was getting harder start look down and my priming pressure just before the fuel relay shuts off said 70psi.

So I turn the key 4 more times without starting and the pressure climbed pass 100psi and the car will not start. :-\

I ran out of pressure regulators.  When I was using a separate fuel pressure tester at the filter just before changing to pressure regulator #3 I had that pressure spike past 200psi. and pump would not stop unless the relay stopped.

I'm using a MSD 2351 box for consistent voltage to pump. I have it set at 13.5 volts when in n/a so I think I am not over volting the pumps.

The fuel pump software shows no high temp or excessive amp draw (like if my ground to the pump was shit)

I know that pressure may vary between pressure regulators and with pumps. I have used 2 cdm Walboro pump (the ones that xeno sales but I can get them cheaper then what he sales them for) , 2 OEM pumps, and 3 OEM (2 EX and 1 CX) pressure regulators.

My fuel pressure sender is reading correct and same as the Snap-On pressure tester on my filter test port.

I need some direction or ideas about this. I can get an AEM regulator for free or I can get 5-6 more OEM regulators and see if any will work. My local Hondaphile has already offered them to me.

Could be that the third one popped because it had been sitting around in dry air for about 4 yrs.?

I doubt it. :-\


 


Title: Re: Fuel pressure issue (sorry about the text)
Post by: Joseph Davis on August 20, 2010, 09:06:25 AM
Too long didn't read all of it, but OEM regulators don't go bad often so you likely have 2-3 good ones on hand.  A Walbro 255HP will overpower a small exit OEM FPR at idle (FP drifts around the 60 psi area until you start passing enough fuel across the injectors that it can handle returning the remainder) but none of that 100 psi shit.

Sounds like you have the wrong washer for your fuel rail/pulse dampener/non pulse dampener combo.  If it has a cross drilled rail inlet you can use the normal washer and vanilla nut, if it's not cross drilled you must use the serrated washer and the pulse dampener nut.

Now post some goddamn redheads (in GD, I try to keep this forum as a work resource) to make up for your wall of text.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: 92CXyD on August 20, 2010, 09:50:23 AM
Too long didn't read all of it, but OEM regulators don't go bad often so you likely have 2-3 good ones on hand.  A Walbro 255HP will overpower a small exit OEM FPR at idle (FP drifts around the 60 psi area until you start passing enough fuel across the injectors that it can handle returning the remainder) but none of that 100 psi shit.

Sounds like you have the wrong washer for your fuel rail/pulse dampener/non pulse dampener combo.  If it has a cross drilled rail inlet you can use the normal washer and vanilla nut, if it's not cross drilled you must use the serrated washer and the pulse dampener nut.

Now post some goddamn redheads (in GD, I try to keep this forum as a work resource) to make up for your wall of text.

The rail in use has the cross drilled inlet and I'm using the washer that came with the non-dampener cap.


I'll see if I can get a rail, dampener, pressure regulator, serrated washer and anything else from a buddy see if this will work. :-\


Title: Re: Fuel pressure issue (sorry about the text)
Post by: snm95ls on August 20, 2010, 10:46:08 AM
So is your "walbro 255" a high pressure unit?

Title: Re: Fuel pressure issue (sorry about the text)
Post by: 92CXyD on August 20, 2010, 10:50:09 AM
So is your "walbro 255" a high pressure unit?



Yeah both of them are.  ;D
Title: Re: Fuel pressure issue (sorry about the text)
Post by: dueyx99 on August 21, 2010, 02:20:22 AM
high pressure walbro 255+ stock regulator is your prob, pick up one of those ebay external regulators, tap the stock fuel rail return for a 5/16" pipe barb fitting and you can easily hook up the regulator to the stock rail, problem solved, continue running walbro 255
Title: Re: Fuel pressure issue (sorry about the text)
Post by: ratcityrex on August 21, 2010, 02:31:03 AM
high pressure walbro 255+ stock regulator is your prob, pick up one of those ebay external regulators, tap the stock fuel rail return for a 5/16" pipe barb fitting and you can easily hook up the regulator to the stock rail, problem solved, continue running walbro 255

R u re tard? Dude I've been rocking a stock fpr, and a walbro 255hp for over 2 years and not 1 problem. The last thing I would do is take a quality Honda part off to replace it with a cdm unit.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: dueyx99 on August 21, 2010, 02:37:54 AM
dunno what to say, i've had nothing but problems with the walbro 255's and stock fpr, especially with the newer 96+ fpr's they seem to have the prob where you see 100psi, had nothing BUT good luck with the ebay regulators, they are a very decent unit.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: Joseph Davis on August 21, 2010, 03:26:54 AM
Duey, read my post.  I've made 640 on an OEM regulator, get with the program.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: PhilStubbs on August 21, 2010, 07:32:03 AM
You think you have had problems cause you like shiny parts. Why do you think there are adaptors out there to use STOCK Honda regulators on other brands of cars? They work. I have been running a real walbro 255 with a stock regulator for 5 years with out a single issue.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: Joseph Davis on August 21, 2010, 11:39:32 AM
I didn't know there were adapters out there, but I do know that Honda FPRs fit neatly in place on most Toyotas.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: PhilStubbs on August 21, 2010, 01:44:54 PM
there are adapters. i just did a quick search and cant seem to find any right now, but i know i have seen them for a few difference cars

Title: Re: Fuel pressure issue (sorry about the text)
Post by: 92CXyD on August 21, 2010, 05:06:45 PM
Alright switched out a fuel rail, sintered washer, dampener, and pressure regulator.

All off a running engine the pressure was at a steady 70psi then slowly bleeds down with power off.

Smelled fuel, Look around and inj. #1 to rail was leaking.

So I pull the injectors and was looking the condition of the o-rings and I had two nicked. Was in process of replacing them and with good lighting I saw in two injectors Aluminum chips in the inlets.

Cleaned them out, replaced o-rings, and put everything back together.

Started the car and it ran better fuel stead at 62-63 psi.

I made a new basemap with the current fuel pressure and now the idles better and when I rev. to 4k w/o load I still get decent AFRs 14:1 to 13:1. ;D

Before I was leaning out bad to like 18:1 or worse.  :-\

I think I have this problem fixed, we'll see. ;D
Title: Re: Fuel pressure issue (sorry about the text)
Post by: ratcityrex on August 21, 2010, 05:53:10 PM
Base psi is still a little high isn't it?
Title: Re: Fuel pressure issue (sorry about the text)
Post by: Joseph Davis on August 21, 2010, 06:52:09 PM
I had a problem Nissan once, turned out the FPR was full of aluminum drill chips and shavings.  IDK how the fuck that happened, but there it is.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: 92CXyD on August 21, 2010, 11:07:19 PM
Base psi is still a little high isn't it?

According to Sewell that 60 psi is common with a 255hp pumps.

Plus I'm a constant 13.5v to the pump instead of what the normal wiring delivers.

I may switch to one the FPRs that have the biggest return line nipple and see that would help bring the pressure down more.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: Teg2boo on August 22, 2010, 12:57:20 AM
Yo JD, what is the limit of a healthy honda fuel pump in HP? Might be out of context, but I'm drunk... What can I do?
Title: Re: Fuel pressure issue (sorry about the text)
Post by: DmC on August 22, 2010, 01:36:08 AM
Yo JD, what is the limit of a healthy honda fuel pump in HP? Might be out of context, but I'm drunk... What can I do?
It's never been consistant for me. Ive had stock pumps run out of flow right away with any boost at all and then Ive seen them be just fine up until about 250hp. it's kind of funny how it works out you really don't see to many people running a stock pump they usaully swap in a walbro on there own. even on a stock motor.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: sewell94 on August 22, 2010, 04:30:29 AM
Ive seen 55-60psi a quite a few times with a 255 and the small regulators.



Hows the tuning comming along russ??



Title: Re: Fuel pressure issue (sorry about the text)
Post by: Joseph Davis on August 22, 2010, 08:17:40 AM
Ive seen 55-60psi a quite a few times with a 255 and the small regulators.

+2, sometimes it drifts a little at idle and makes idle AFRs wander, but it's fine as soon as you start moving.  Big exit regulators are fine all the time.


Yo JD, what is the limit of a healthy honda fuel pump in HP? Might be out of context, but I'm drunk... What can I do?

Not sure, but my gut feeling is that it's the same pump as the 92-95 CX, which is the same pump as everything else distributor Honda.  If you feed it 10-12 gauge power and ground you can break 300 whp by a good margin on a Mustang dyno.  That all over the place shit DmC describes is an individual car-by-car expression of how rotted the unibody is with stock fuel pump wiring.
Title: Re: Fuel pressure issue (sorry about the text)
Post by: 92CXyD on August 22, 2010, 09:44:12 AM
Ive seen 55-60psi a quite a few times with a 255 and the small regulators.

Hows the tuning comming along russ??


Going ok so far. I've done a basic n/a tune and putting the s/c and original IC piping back on today.

Make new upper s/c brackets then I'll do some more tuning.  ;D