It took me a while to get to it, but re-opening an old thread, I wanted to point out that I had a solution- I pressurized my intake, corking the tailpipe and used my handy home-made smoke generator:
Dry-ice in a ketchup bottle wrapped in a towel (to insulate it), and duct tape liberally applied, with a straw hot-glued into the lid to draw the "smoke" from the center of the bottle when the bottle is inverted. Add warm water to make the smoke start. I saw an unusual amount of the fumes being pulled into a stream from just about the most inaccessible place on the engine- under the supercharger and above the manifold. So it was off with the supercharger. And look what I found: <http://www.hazmat.com/~mjb/gallery/main.php?g2_view=core.ShowItem&g2_itemId=3583> Can anyone tell me where the massive vacuum leak is? I put a new gaskget in (a thinner, stronger material) and the MAP levels are reading in the 30 range at idle, and no idle fuel-cut oscillations! Now, I might just be able to tune! Matt Matt Bennett '96 with prototype Ubercharger On Sun, September 21, 2008 12:10 pm, Bill Cardell wrote: > You don't need all the valves closed, just cork the tailpipe and inlet. > > > Bill Cardell > TurboDog's Dad > www.flyinmiata.com > www.fmwestfield.com > orders 1-800-FLY-MX5S > Before you call our tech line (970.464.5600) please check out the FAQ > section of our website > > > > -----Original Message----- > From: Matt Bennett [mailto:[EMAIL PROTECTED] > Sent: Sunday, September 21, 2008 10:30 AM > To: [email protected] > Cc: Bill Cardell > Subject: RE: Help diagnosing an intake leak > > Well, I did the disassembly to disconnect the TPS, and as soon as I > start it, the RPM shoots up to 5000, and stays there. The vacuum gauge > is showing about 20 (I didn't take a look at what the Link was telling > me). > Adjusting the air screw doesn't make a bit of difference. The Link is > reading 50 on the TPS while unplugged. I plug the TPS back in, and it > goes back to the oscillating idle. > > I guess it's back to engine off diagnosis- pressurizing the intake- > without taking the valve cover off to look at the camshafts, is there > any other way/crankshaft position that will have all the intake valves > closed? > > >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of Matt Bennett >> Sent: Sunday, September 21, 2008 10:54 AM >> To: Bill Cardell >> Cc: [email protected] >> Subject: RE: Help diagnosing an intake leak >> >> On the subject of an Uber manifold-- the TPS is well-nigh impossible >> to get off without disassembling the bypass- I've been trying the >> propane trick, but with the idle oscillating up to fuel cut and >> back... I haven't been able to diagnose anything. Is there any way I >> can use the Link to ignore the TPS enough? Maybe change the offset? >> >> Just for kicks, I tried the propane trick while the engine was >> idle-oscillating- no difference. I unplugged the PCV and put the >> propane straight into that hose, and no difference! >> >> Matt >> >> On Mon, September 15, 2008 9:55 pm, Bill Cardell wrote: >>> It's an uber manifold, so that one isn't there. A plethora of new >>> possibilities for leaks instead. >>> >>> >>> Bill Cardell >>> TurboDog's Dad >>> www.flyinmiata.com >>> www.fmwestfield.com >>> orders 1-800-FLY-MX5S >>> Before you call our tech line (970.464.5600) please check out the FAQ > >>> section of our website >>> >>> >>> >>> -----Original Message----- >>> From: [EMAIL PROTECTED] >>> [mailto:[EMAIL PROTECTED] On Behalf Of Ray Ayala >>> Sent: Monday, September 15, 2008 8:27 PM >>> To: [EMAIL PROTECTED] >>> Cc: [email protected] >>> Subject: Re: Help diagnosing an intake leak >>> >>> Have you already checked the infamous cap on the rear manifold > nipple? >>> >>> >>> ----- Original Message ----- >>> From: "Matt Bennett" <[EMAIL PROTECTED]> >>> To: "Ray Ayala" <[EMAIL PROTECTED]> >>> Cc: <[email protected]> >>> Sent: Monday, September 15, 2008 7:16 PM >>> Subject: Re: Help diagnosing an intake leak >>> >>> >>>> The original thing I tried was to block off the intake with a dog >>> 'Kong' >>>> modified with an air hose end. Thankfully, my wife thought of the >>> Kong >>>> before I had to go down to the adult toy store and look for what >>>> originally came to mind (Rhymes with 'mutt' plug). Just think of >>>> that >>>> conversation- "Honestly, I need the extra large one, for my car!" >>> <yeah, >>>> right, they would have thought". >>>> >>>> I ended up putting the (low) pressure in via the power-brake booster >>> hose. >>>> That did allow me to eliminate that hose and the stuff directly >>> connected >>>> to that- I unplug it from the SC, cover the hose end with my finger, >>> the >>>> hissing goes away. I definitely hear something that sounds like it >>>> is coming from the engine area, but I *really* don't want to take >>>> off the intake manifold, or the SC if I can help it. >>>> >>>> Matt >>>> >>>> On Mon, September 15, 2008 7:15 pm, Ray Ayala wrote: >>>>> Have you tried simply blocking off the SC inlet to see if there's >>> still >>>>> enough intake air to idle? On a TB I use a jar lid with a >>>>> molded-on gasket as a cap but have never personally tried it with >>>>> an SC inlet. >>>>> >>>>> >>>>> ----- Original Message ----- >>>>> From: "Matt Bennett" <[EMAIL PROTECTED]> >>>>> To: <[email protected]> >>>>> Sent: Monday, September 15, 2008 7:42 AM >>>>> Subject: Help diagnosing an intake leak >>>>> >>>>> >>>>>> After what Ray pointed out to me (below), I looked at some old DLL >>> logs >>>>>> and saw that my Idle MAP reading that is now about 70 used to be >>>>>> in >>> the >>>>>> 40 >>>>>> range. So I slapped myself around a bit and started to look for a > >>>>>> vacuum leak. I haven't found anything particularly bad. >>>>>> >>>>>> Anyone have any tip or tricks on looking for an intake leak? I >>> tried >>>>>> pressurizing the intake to a few PSI with my compressor and >>> listening >>>>>> for >>>>>> hissing, but it has been really hard to localize- possibly going >>> through >>>>>> an open intake valve?. One thing that I was wondering- how much >>>>>> of >>> the >>>>>> stock 1.8l engine's cycle has all of the intake valves closed? I >>> did >>>>>> find >>>>>> a better place to put the fuel pressure regulator's vacuum hose, >>>>>> but wiggling stuff around hasn't brought me any closer to bringing > >>>>>> the vacuum down to a more appropriate value. >>>>>> >>>>>> Regards, >>>>>> >>>>>> Matt >>>>>> '96 with prototype Ubercharger >>>>>> >>>>>> >>>>>> On Sun, September 7, 2008 1:12 pm, Ray Ayala wrote: >>>>>>> The log shows the idle switch signal on even when the map signal >>> show >>>>>>> that >>>>>>> either the throttle is open or there's a big intake air leak. >>>>>>> The >>> idle >>>>>>> switch signal kills the fuel completely when rpm is above the >>>>>>> idle control range (~1850 rpm). >>>>>>> >>>>>>> >>>>>>> ----- Original Message ----- >>>>>>> From: "Matt Bennett" <[EMAIL PROTECTED]> >>>>>>> To: <[email protected]> >>>>>>> Sent: Saturday, September 06, 2008 7:39 PM >>>>>>> Subject: Bucking, DLL help >>>>>>> >>>>>>> >>>>>>>> Howdy folks, I'm trying to figure out my latest issue, I seem >>>>>>>> to remember this type of problem being discussed before, but I >>>>>>>> didn't take adequate notes. Right now, the most annoying >>>>>>>> problem I have is that my car >>> has >>>>>>>> some very abrupt on/off transitions- also the "idle oscillation" >>> is >>>>>>>> pretty >>>>>>>> bad. You can see both of these characteristics in this (really >>> long) >>>>>>>> log: >>>>>>>> >>>>>>>> >>> <http://www.hazmat.com/~mjb/projects/miata/DataLogs/2008-09-06a.bin> >>>>>>>> >>>>>>>> The vitals on this car: >>>>>>>> 1996 with prototype Ubercharger (intercooled, with air >>>>>>>> temperature >>>>>>>> sensor) >>>>>>>> 550cc Injectors >>>>>>>> Vishnu Dual feed fuel rail >>>>>>>> Link ECU (non OBD- I believe that this is referred to as a 94-95 >>> Link) >>>>>>>> AEM WB02 >>>>>>>> Stock engine internals >>>>>>>> Setup for (but not installed) NB02 >>>>>>>> >>>>>>>> >>>>>>>> Another thing I'm thinking of- I realize that tuning on the road >>> is >>>>>>>> difficult, dangerous, and often runs afoul of the law- has >>>>>>>> anyone created a script for the most cost effective way to use a > >>>>>>>> dyno? The one >>> that >>>>>>>> I >>>>>>>> can rent time on is a brake dyno (not a Dynojet). I want to >>>>>>>> tune >>> for >>>>>>>> 1) >>>>>>>> emissions and 2) power with drivability- and 1 and 2 don't have >>>>>>>> to >>> be >>>>>>>> the >>>>>>>> same map :) >>>>>>>> >>>>>>>> The vast majority of the adjustments appear to be with fuel- is >>>>>>>> it because changing fuel zones is easier and more effective than > >>>>>>>> adjusting timing? >>>>>>>> Or is timing just a lot more dangerous to play with. >>>>>>>> >>>>>>>> With the 94-95 link, can I have both WB and NB O2 sensors > logged? >>> I >>>>>>>> realize only one will actually be adjusting settings. If I tune >>> for >>>>>>>> one >>>>>>>> sensor, will I need to change maps when I move between sensors, >>>>>>>> or >>> can >>>>>>>> I >>>>>>>> just do it through the Link keypad? >>>>>>>> >>>>>>>> I realize I need to sit down with the tuning manuals from FM- I >>> went >>>>>>>> looking on Flyin' Miata's site and didn't find the Link tuning >>> manual- >>>>>>>> I've got an old copy- what is the latest revision? >>>>>>>> >>>>>>>> Regards, >>>>>>>> >>>>>>>> Matt Bennett >>>>>>>> Austin, TX >>>>>>>> '96 with prototype Ubercharger >>>>>>>> _______________________________________________ >>>>>>>> Miatapower mailing list >>>>>>>> [email protected] >>>>>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Miatapower mailing list >>>>>> [email protected] >>>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>> >>>> >>> >>> _______________________________________________ >>> Miatapower mailing list >>> [email protected] >>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>> >> >> _______________________________________________ >> Miatapower mailing list >> [email protected] >> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >> >> > > _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
