engine vacume and AFPR
Thread Starter
Burning Brakes
Joined: Sep 2000
Posts: 1,199
Likes: 1
From: NewCastle IN. USA
engine vacume and AFPR
does anyone know of a way to get the adjustable fuel regulator to take out more pressure with less vacume?
Right now I'm getting around 16 inchs of vac at idle (it varies with idle speed).
this only pulls out about 8 psi in fuel pressure (mini-ram set up).
its super rich at idle, and lean at upper rpms. so if I can get it to pull out more pressure I hope to get it leaner at idle, and let me put more fuel pressure in without vacume.
so any ideas?
Right now I'm getting around 16 inchs of vac at idle (it varies with idle speed).
this only pulls out about 8 psi in fuel pressure (mini-ram set up).
its super rich at idle, and lean at upper rpms. so if I can get it to pull out more pressure I hope to get it leaner at idle, and let me put more fuel pressure in without vacume.
so any ideas?
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: engine vacume and AFPR (ol,RJ)
You might not like the explanation but this is because with your setup--and mainly your cam, you are less volumetrically efficient at low RPMS and more at higher RPMs. The best way to take care of this is running a data logger to see where the transition is, and then have a few chips done for it.
I had the same prob, even though my setup is not as radical as yours. Just a cam swap and I couldn't dop much with the AFPR to help the situation, so I changed my VE tables in the PROM. -Matt-
I had the same prob, even though my setup is not as radical as yours. Just a cam swap and I couldn't dop much with the AFPR to help the situation, so I changed my VE tables in the PROM. -Matt-
Thread Starter
Burning Brakes
Joined: Sep 2000
Posts: 1,199
Likes: 1
From: NewCastle IN. USA
Re: engine vacume and AFPR (HighHopes85)
thanks for the reply highhopes85,
Famato's is working on another chip now (hopefully). I was suprised that it got this much vac.
I think I'll see if they can raise the idle speed a little more, it has better vacume at 1000rpm (20inchs). its still not enough to lean it out but its more stable.
seems like I remember someone posting something about the AFPR's from TPIS, like they had to replace a washer inside?
RJ
Famato's is working on another chip now (hopefully). I was suprised that it got this much vac.
I think I'll see if they can raise the idle speed a little more, it has better vacume at 1000rpm (20inchs). its still not enough to lean it out but its more stable.
seems like I remember someone posting something about the AFPR's from TPIS, like they had to replace a washer inside?
RJ
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: engine vacume and AFPR (ol,RJ)
I have heard of a few people shimming something using a penny or dime, but I never popped open my regulator to take a look at it. Might be worth a shot (only costs 1 cent or 10...). -Matt-
Burning Brakes
Joined: Feb 2000
Posts: 1,247
Likes: 2
From: Parker, Colorado, USofA
Re: engine vacume and AFPR (ol,RJ)
I wonder if you could plumb in a vacuum pump...ZR-1's come with one from the factory to ensure the vacuum system is primed and has enough vacuum during certain motor conditions.
(In a well set up ZR-1, you can hear that pump turn on for a few seconds before hitting the ignition.)
(In a well set up ZR-1, you can hear that pump turn on for a few seconds before hitting the ignition.)
Thread Starter
Burning Brakes
Joined: Sep 2000
Posts: 1,199
Likes: 1
From: NewCastle IN. USA
Re: engine vacume and AFPR (HighHopes85)
hmmm. guess I'll have to take it apart and see whats going on in there.
never knew the ZR1 had a extra vacume pump. don't know how I could hook it into the system, would take some computer control I think.
wonder if a slightly softer spring in the regulator would do the trick.?
hopefully a new prom will make a step in the right direction.
thanks for the input guys :)
never knew the ZR1 had a extra vacume pump. don't know how I could hook it into the system, would take some computer control I think.
wonder if a slightly softer spring in the regulator would do the trick.?
hopefully a new prom will make a step in the right direction.
thanks for the input guys :)
Burning Brakes
Joined: Feb 2000
Posts: 1,247
Likes: 2
From: Parker, Colorado, USofA
Re: engine vacume and AFPR (ol,RJ)
It sits down in the well underneath one headlight, and I believe it's pressure actuated...meaning all it'd need is a 12v powersource, and very minor plumbing.
Thread Starter
Burning Brakes
Joined: Sep 2000
Posts: 1,199
Likes: 1
From: NewCastle IN. USA
Re: engine vacume and AFPR (RocketSled)
thanks for the info RocketSled, neat stuff (ZR1's are cool anyway, wish someone would let me drive one :D they say is for my own good :) ).
I called Fomato's today, they can lean out the idle more and I asked them to raise the idle up so its going to be 975rpm now. that should help some.
they were a little stumped about the diacom info I sent them until we talked on the phone, still a bit weird to both of us. But their going to look it over good tonight and send a updated chip off tomorrow :cool:
Now if I can just get one day of nice weather to try it out once it comes.
RJ
[Modified by ol,RJ, 1:10 AM 11/28/2001]
I called Fomato's today, they can lean out the idle more and I asked them to raise the idle up so its going to be 975rpm now. that should help some.
they were a little stumped about the diacom info I sent them until we talked on the phone, still a bit weird to both of us. But their going to look it over good tonight and send a updated chip off tomorrow :cool:
Now if I can just get one day of nice weather to try it out once it comes.
RJ
[Modified by ol,RJ, 1:10 AM 11/28/2001]
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