DIY_EFI Digest Sunday, November 7 1999 Volume 04 : Number 628 In this issue: DIY_EFI Digest V4 #607 FW: Re Motronic 4.1 newbie-continued Re: DIY_EFI Digest V4 #627 Re:alfa motronic No html See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Sat, 06 Nov 1999 13:20:18 -0700 From: Doug Dayson Subject: DIY_EFI Digest V4 #607 Hi rpettibo...sorry...didn't catch your name... I'm very interested in your Performer vs Victor Jr dyno charts... I see the peak torque and HP improvements mentioned below...what were the other changes in the total torque curves? Below 4000 rpm...above 4000 rpm...below 2000...below 3000 etc... In my experience the difference between dual planes and single planes occurs around 4000 rpm...single better above and dual better below... Did you notice that with your carbureted dual plane to MPI single plane conversion? What rpm do you shift at and recover to? TIA...Doug > Date: Wed, 27 Oct 1999 17:19:30 -0700 > From: rpettibo@xxx.com > Subject: Re: DIY_EFI Digest V4 #606 Re: Intakes > > On the issue of single vs dual plane, I converted a 383 Chevy from a > Edelbrock Performer RPM (Dual Plane) and Holley 750 (#3310) to an EFI > using a Victor JR with sequential port injectors. Torque increased over > 50 lb/ft and HP by 30. Both set ups were dyno tuned. From my experience > the best air-flowing manifold is the one to go with for EFI applications. > I know the runners on the Victor flow much better than the Performer on the > flowbench. I don't remember what the numbers were but it was significant. > The other VERY interesting thing about this conversion was an increase in > maifold vacuum. With the carb I ran 12" at idle, which is about right with > my solid roller cam (244in, 249ex @xxx. With the fuel > injection I am at 15.8 - 16". Anybody see this on other applications? I > still find it hard to believe. > One thing is for sure injection is worth the price of admission. ------------------------------ Date: Sat, 6 Nov 1999 23:36:46 -0000 From: "Rich M" Subject: FW: Re Motronic 4.1 newbie-continued This is a multi-part message in MIME format. - ------=_NextPart_000_0001_01BF28B1.2602BFA0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit -----Original Message----- From: Rich M [mailto:rsrich@xxx.net] Sent: 06 November 1999 23:33 To: diy_efi (E-mail) Subject: Re Motronic 4.1 newbie-continued ------------------------------ Date: Fri, 05 Nov 1999 20:44:33 EST From: "Derek Kaznoski" Subject: Motronic 4.1 newbie-continued >I took off the ISA and examined it. The valve >seemed to open and close >without difficulty. I went ahead and cleaned it with throttle >body cleaner >to be sure (thanks Dylan). I noticed that in the fully closed >position, >there was about a 3mm gap present, i.e., the valve is over- >rotated past the >closed position. That's right; in the de-energised condition, the valve returns to it's endstop which exposes a default opening which should correspond to a high-idle setting. This is used as a fail-safe to produce a useable (if little high) idle speed if the ISA or it's drive fails. >I'm >planning to replace it. If anyone thinks this is a bad idea, >please let me >know. Any other input is greatly appreciated. Before you replace it, check for splits or leaks in the air tubing/trunking on the engine side of the airflow meter and ISA. I have come across a similar effect of rough idle on a LE2 sytem for just this reason: at idle the leak represents a significant bypass round the airflow meter, so allowing the flap to close and cut off the fuel creating a very weak mixture. As the throttle is opened, the leak becomes less and less significant and engine operation appears to return to normal. This is obviously only one possibility, but it is very real; the split doesn't need to be that big - check carefully round any concertina sections of air trunking where splits may not at first be obvious. hope this might help. Rich - ------=_NextPart_000_0001_01BF28B1.2602BFA0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
-----Original Message-----
From: Rich M=20 [mailto:rsrich@xxx.net]
Sent: 06 November 1999 = 23:33
To:=20 diy_efi (E-mail)
Subject: Re Motronic 4.1=20 newbie-continued

------------------------------

Date: Fri, 05 Nov 1999 20:44:33 EST

From: "Derek Kaznoski"=20 <sweetpea1998@xxx.com>

Subject: Motronic 4.1 newbie-continued

 >I took off = the ISA and=20 examined it. The valve

>seemed to open and close

>without difficulty. I went ahead and cleaned it = with=20 throttle

>body cleaner

>to be sure (thanks Dylan). I noticed that in the = fully=20 closed

>position,

>there was about a 3mm gap present, i.e., the = valve is=20 over-

>rotated past the

>closed position.

That's right; in the de-energised condition, the = valve returns=20 to it's endstop which exposes a default opening which should = correspond to a=20 high-idle setting. This is used as a fail-safe to produce a useable = (if little=20 high) idle speed if the ISA or it's drive fails.

>I'm

>planning to replace it. If anyone thinks this is = a bad=20 idea,

>please let me

>know. Any other input is greatly = appreciated.

Before you replace it, check for splits or leaks in = the air=20 tubing/trunking on the engine side of the airflow meter and ISA. I = have come=20 across a similar effect of rough idle on a LE2 sytem for just this = reason: at=20 idle the leak represents a significant bypass round the airflow meter, = so=20 allowing the flap to close and cut off the fuel creating a very weak = mixture.=20 As the throttle is opened, the leak becomes less and less significant = and=20 engine operation appears to return to normal.

This is obviously only one possibility, but it is = very real;=20 the split doesn't need to be that big - check carefully round any = concertina=20 sections of air trunking where splits may not at first be = obvious.

hope this might help.

Rich

- ------=_NextPart_000_0001_01BF28B1.2602BFA0-- ------------------------------ Date: Sat, 6 Nov 1999 19:15:25 -0600 From: nacelp@xxx.com (CSH-HQ) Subject: Re: DIY_EFI Digest V4 #627 In the Dec 99 of four wheeler they talk about ATS, and some new diesel stuff, for the EFI ones. Of interesting note is a dual thermostat arrangement for turbo applications of the gm 6.5, and Propane injection (for the long term memory buffs, I was asking about that several months, maybe a year, ago). They also, have a 130 gph water pump!. Grumpy ------------------------------ Date: Sat, 6 Nov 1999 23:08:31 EST From: JCsDOOR@xxx.com Subject: Re:alfa motronic I would check your ntc temp sender, be sure to check cold to hot. An out of speck temp sender will give the same simption. Jim crance CO.Springs,CO. ------------------------------ Date: Sun, 7 Nov 1999 20:55:00 +1100 From: "Geoff Richards" Subject: No html Could we please have all html turned off Geoff Richards ------------------------------ End of DIY_EFI Digest V4 #628 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".