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Date:         Wed, 23 May 2001 09:00:43 -0400
Reply-To:     Jay L Snyder <Jay.L.Snyder@usa.dupont.com>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Jay L Snyder <Jay.L.Snyder@usa.dupont.com>
Subject:      Re: Fuel Injection (Long)
Comments: To: Mike Finkbiner <mike_l_f@hotmail.com>
Content-type: text/plain; charset=us-ascii

I would expect less vacuum with a longer duration cam, no? Maybe an adjustable FPR is necessary.

Jay

Mike Finkbiner <mike_l_f@hotmail.com> on 05/22/2001 11:38:21 PM

Please respond to Mike Finkbiner <mike_l_f@hotmail.com>

To: vanagon@GERRY.VANAGON.COM cc: (bcc: Jay L Snyder/AE/DuPont) Subject: Re: Fuel Injection (Long)

Mark (and all of the others that have contributed) - To re-cap, I've been getting poor mileage and power on a new Boston Bob 2.1 l engine with the longer duration cam and polished heads. I have a Digitool, and the readings look in line with Darrel's specs, and not very different than the old engine. #3 cylinder is only 110 psi, the other 3 are 130-140, and the fuel pressure regulator is about 4# high at idle. I have put about 1200 miles on the engine, mostly on 55 mph highways. A mechanic who ran an emissions test said that the CO looked OK but the hydrocarbons are high, probably because of the cam. Mark and a couple of others have suggested that it's not the cam, but the fuel pressure regulator (FPR) or the air flow meter (AFM) not properly adjusted. Several people suggested that we get the valves dialed in and see if that helps the compression. Since last we spoke, there have been a few developments. I tried running it with the idle stabiliser disconnected - no difference, but it was good to learn how to test it. Leaning out the mixture using the AFM seemed a good bet, and one thing I did notice using the digitool was that the warm idle reading on the AFM was ~1.65. Darrel's notes suggest 1.5, so I opened it up, marked the current location, and turned the gear wheel 2 clicks counter clockwise. Now the warm reading is ~1.5, and I seem to have more power. Another area that was brought up was engine vacuum. If it isn't strong enough, the FPR will have a higher pressure reading. My mechanic adjusted the valves today (1/4 turn in?) and measured the vacuum before and after. About 6.5 psi before, and about 8 after. Mark says that should be about 11-13 psi, so there is something wrong. There don't appear to be any vacuum leaks on the new hoses. One possibility is that the valves have to more thoroughly seat before the vacuum will come up. We plan to run it for a week or so and re-test the vacuum. I need to get it out for a run to see what the mileage is now. Now that the valves are adjusted, another thing I hope to verify is how to check the CO using the O2 sensor. Mark says that .5 volts = 5% CO, so I'm assuming that I can warm up the engine, shut it off, disconnect the O2 sensor, connect a meter, re-start, and read the idle O2 off the meter. Then I could use the idle CO screw on the AFM to adjust it. My digitool shows it bouncing from negative numbers to .8 or so at highway speeds, so I think it's working OK, but it would be nice to know. I'm hoping to talk to Boston Bob tomorrow to see if he has any other thoughts, and I'll keep reporting on what's happening in case any of the rest of you have similar problems. Darn this gets complicated! - Mike Finkbiner '87 Westy Moscow, Idaho

>From: Mark Keller <kelphoto@islandnet.com> >To: Mike Finkbiner <mike_l_f@hotmail.com>, Vanagon List ><vanagon@gerry.vanagon.com> >Subject: Re: Fuel Injection >Date: Wed, 16 May 2001 22:10:32 -0800 >Mike, > >Well, if your low on the #3 cylinder that may would have to be worked >out first. If you said 4 lbs high, as in 29 + 4 = 33 lbs at idle with the >vacuum hose connected and your getting around 12 inches of vacuum you have >a problem with the pressure regulator as that's over half of the range. >29- 36 is operating range of high to low load or vacuum -- not a tolerance. >If you have 36 + 4 =40 lbs at the above conditions you >have a bigger >problem with the pressure regulator. > >I don't mean to sound harsh, but I believe that 4 psi at idle is enough to >put your HC up. Mine run at 50 ppm HC on the lean side but ok. The other >thing is you don't mention attempting to adjust the idle air bypass, aka CO >adjustment. This could also be out of adjustment. Most people myself >include use the O2 sensor output voltage to set CO since there is nearly a >exact correlation i.e. .5 volts =5% CO etc.-- this tip is in the Bosch Fuel >injection Book by Probst. And it really matters what vacuum your getting >at idle. BTW I have a spare fuel pressure regulator for what it's worth you >can try it out. > >Also while were here, the first thing that should be done is to set the >spring tension or verify it by looking for an O2 sensor output reading in >the .5 volts- .7 volts range while the engine is at 3000 rpm. This is also >covered recently, but its' mainly moving the geared wheel under the afm >cover. Once the spring tension is right, check the settings. > >BTW, the O2 sensor is disconnect from the computer in these scenarios. I've >had the 4 gas analyzer done too, but using an O2 is probably is just as >good. > > You didn't mention if you had read the posts I referred to. Lilley is >the one who stated that High HC at idle in his own van caused him to fail >emission as was due to high fuel pressure because of a cracked vacuum line >not the cam as you suggest. > >If your engine is warm the idle stabilizer in not operation, it only for >cold engine warm up. The idle stabilizer in fact adjusted by >disconnecting it, and then adjusting the idle manually. > >I wrote this kinda quick, so email me if something is unclear. > >Sincerely, >Mark > >Mike Finkbiner wrote: > > > > Mark - > > > > It's an interesting problem, and probably has several components. The >engine is still tight, and #3 cylinder is reading only 110 psi, so we >probably need to adjust the valves, but the rhythmic surging at steady >speeds really puzzles me. > > > > The high HC at idle is probably from the longer duration cam that Bob >put in. This engine has the ported and polished heads with the Lilly cam >that is supposed to provide more grunt without sacrificing reliability. It >will be nice if that turns out to be true! > > > > The mechanic who ran the emissions tests said they looked good other >than that. There is currently no cat in the system. > > > > Another listee suggested disconnecting the idle stabilizer temporarily. >I also have a new Temp II sensor. They will be a lot cheaper to check than >ordering a new fuel pressure regulator. > > > > Current plan is to disconnect the idle stabilizer before I take a 100 >mile drive on Saturday, then check the valves early next week, and replace >the Temp II. > > <SNIP> _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com


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