 L-Jet going full Rich on Deceleration |
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| Brian Fuerbach |
 Mar 27 2022, 06:36 PM
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#1
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Member  Group: Members Posts: 119 Joined: 1-July 19 From: Orange, Ca Member No.: 23,266 Region Association: Southern California  |
1974 1.8 with L- jet. Been playing with a wide band air fuel meter and noticed that when I lift the throttle the AFR goes to max value on the gauge. I thought it was supposed to go lean. I checked the throttle position switch and it checks out fine. Going to check the wiring harness next.
What else should I check? Decel valve? |
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| emerygt350 |
Mar 30 2022, 06:17 PM
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#2
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Advanced Member Group: Members Posts: 2,982 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
I bet Mr. Injector could tell us exactly how they perform at sub 28 psi.
My gt350 has this crazy soft fall mechanism on the throttle body to stop the same kind of dip issue on throttle close. 14 years later, well 10 years after l-jet, with O2 sensors, and space shuttle computers, and they still couldn't keep a fuel injected motor running with a rapid throttle close. It was so bad, and fudged, that they wouldn't even give you fuel injection with a manual transmission. That took several years for cfi and a complete change to multiport injection (86) for the 302 ho. |
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| wonkipop |
Mar 30 2022, 06:34 PM
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#3
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Advanced Member Group: Members Posts: 4,807 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille 
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QUOTE(emerygt350 @ Mar 30 2022, 06:17 PM)  I bet Mr. Injector could tell us exactly how they perform at sub 28 psi. My gt350 has this crazy soft fall mechanism on the throttle body to stop the same kind of dip issue on throttle close. 14 years later, well 10 years after l-jet, with O2 sensors, and space shuttle computers, and they still couldn't keep a fuel injected motor running with a rapid throttle close. It was so bad, and fudged, that they wouldn't even give you fuel injection with a manual transmission. That took several years for cfi and a complete change to multiport injection (86) for the 302 ho. interesting what you say about no manual with fuel injection. the EC-A, EC-B research i did turned up that VW pushed the L jet into production with primary focus on the VW 412 with auto trans. they could not make D jet work with auto trans and pass emissions test and be driveable. but they could achieve it with L jet. 3 months after the 412 comes the 914 with L jet. and a manual trans. and quite a different set up in terms of distributor, decel valve operation etc. all tweaked differently. hard to find out info on 412 with the 74 L jet setup. and do i really want to know. not really. but it is different the way it all works. think it even copped an EGR when the 914s didn't. |
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Posts in this topic
Brian Fuerbach L-Jet going full Rich on Deceleration Mar 27 2022, 06:36 PM
emerygt350 My mustang goes super lean on throttle lift, as it... Mar 27 2022, 06:44 PM Van B I haven’t measured my AFR to compare so, I canâ€... Mar 27 2022, 07:19 PM
Brian Fuerbach
I haven’t measured my AFR to compare so, I canâ... Mar 27 2022, 09:50 PM Van B Ok so, two thoughts:
1.) set your decel valve to ... Mar 27 2022, 10:04 PM Brian Fuerbach
Ok so, two thoughts:
1.) set your decel valve to... Mar 27 2022, 10:45 PM Brian Fuerbach
Ok so, two thoughts:
1.) set your decel valve to... Mar 28 2022, 10:34 PM Van B Ok, I’m too tired to think straight but yes, you... Mar 28 2022, 12:29 AM wonkipop
Ok, I’m too tired to think straight but yes, yo... Mar 28 2022, 01:34 AM emerygt350 But here he is running a 123 right? so you have to... Mar 28 2022, 08:43 AM Van B Definitely possible.
As you've seen through my... Mar 28 2022, 09:13 AM Van B
Definitely possible.
As you've seen through m... Mar 28 2022, 09:17 AM emerygt350
Definitely possible.
As you've seen through ... Mar 28 2022, 09:24 AM Van B AFM is literally the barn door. it attaches to the... Mar 28 2022, 09:36 AM emerygt350
AFM is literally the barn door. it attaches to th... Mar 28 2022, 10:38 AM Van B
AFM is literally the barn door. it attaches to t... Mar 28 2022, 10:43 AM wonkipop
AFM is literally the barn door. it attaches to th... Mar 28 2022, 03:00 PM ClayPerrine The AFM in an L-Jet system will push fuel into the... Mar 28 2022, 09:48 AM emerygt350 So a decel hooked to the boot would be unmeasured ... Mar 28 2022, 10:37 AM Van B
So a decel hooked to the boot would be unmeasured... Mar 28 2022, 10:42 AM wonkipop
So a decel hooked to the boot would be unmeasured... Mar 28 2022, 03:41 PM emerygt350 Is this correct?
I know they changed stuff every... Mar 28 2022, 10:44 AM emerygt350 If it is, man that doesn't make much sense to ... Mar 28 2022, 10:47 AM Van B
If it is, man that doesn't make much sense to... Mar 28 2022, 10:56 AM emerygt350 Too much advance could certainly do it, but there ... Mar 28 2022, 11:02 AM Van B the little subset square on the airbox is meant to... Mar 28 2022, 10:45 AM Brian Fuerbach Regardless of the vac adv or retard, the centrifug... Mar 28 2022, 01:43 PM Van B
Regardless of the vac adv or retard, the centrifu... Mar 28 2022, 05:16 PM emerygt350 Yeah,we were only speculating on 'way too much... Mar 28 2022, 02:04 PM r_towle My experience with this is two things.
1) a dirty ... Mar 28 2022, 03:06 PM emerygt350 But wonkipop, that completely ignores the ecus res... Mar 28 2022, 03:52 PM wonkipop
But wonkipop, that completely ignores the ecus re... Mar 28 2022, 03:56 PM emerygt350 I would bet it does, otherwise they would have jus... Mar 28 2022, 04:20 PM wonkipop
I would bet it does, otherwise they would have ju... Mar 28 2022, 04:59 PM emerygt350 It would be interesting to know what the dizzy con... Mar 28 2022, 05:09 PM wonkipop
It would be interesting to know what the dizzy co... Mar 28 2022, 05:53 PM wonkipop ps
i was trying to look for info on the fpr in th... Mar 28 2022, 06:40 PM wonkipop @Emerygt350 .
always have to go back and re-read ... Mar 28 2022, 08:11 PM Van B Your vac readings are what my decel valve yielded ... Mar 28 2022, 10:55 PM wonkipop
Your vac readings are what my decel valve yielded... Mar 29 2022, 12:51 AM wonkipop i'll translate the above rambling thought.
be... Mar 29 2022, 01:08 AM wonkipop i did a bit more reading.
because i was intereste... Mar 29 2022, 07:25 AM emerygt350 That makes good sense. Mar 29 2022, 08:59 AM Brian Fuerbach Appreciate all the replys. Took me a bit to read t... Mar 29 2022, 02:37 PM wonkipop
Appreciate all the replys. Took me a bit to read ... Mar 29 2022, 03:02 PM Brian Fuerbach
Appreciate all the replys. Took me a bit to read... Mar 29 2022, 04:10 PM wonkipop try measuring the Air Fuel Mix at idle too to comp... Mar 29 2022, 04:45 PM wonkipop @Brian Fuerbach
that description above about L je... Mar 29 2022, 05:04 PM Brian Fuerbach
[b]@[url=http://www.914world.com/bbs2/index.php?s... Mar 29 2022, 07:36 PM wonkipop that is correct brian
Mar 29 2022, 08:26 PM wonkipop i am doing some more reading on just how the L jet... Mar 29 2022, 08:38 PM Brian Fuerbach
by looking for info on your afr condition i now... Mar 30 2022, 09:36 AM wonkipop
by looking for info on your afr condition i no... Mar 30 2022, 04:09 PM Brian Fuerbach
[quote name='Brian Fuerbach' post='2991765' date=... Mar 30 2022, 05:20 PM emerygt350 The fouling is something to think about though. I... Mar 30 2022, 05:03 AM wonkipop
The fowling is something to think about though. ... Mar 30 2022, 06:39 AM emerygt350
The fowling is something to think about though. ... Mar 30 2022, 06:47 AM wonkipop
[quote name='wonkipop' post='2991722' date='Mar 3... Mar 30 2022, 04:16 PM Brian Fuerbach
[quote name='wonkipop' post='2991722' date='Mar ... Mar 30 2022, 05:10 PM emerygt350
[quote name='wonkipop' post='2991854' date='Mar 3... Mar 30 2022, 05:30 PM emerygt350 Let's just blame autocorrect on all of that...... Mar 30 2022, 05:26 PM wonkipop
Let's just blame autocorrect on all of that..... Mar 30 2022, 05:59 PM wonkipop chookyard = chickenyard.
think the limeys call th... Mar 30 2022, 05:39 PM Van B
chookyard = chickenyard.
think the limeys call t... Mar 30 2022, 08:26 PM wonkipop
chookyard = chickenyard.
think the limeys call ... Mar 30 2022, 09:38 PM wonkipop here is another note on that decel thing.
the ide... Mar 30 2022, 06:16 PM Brian Fuerbach I checked the fuel press reg and all is golden. :... Mar 30 2022, 08:40 PM wonkipop
I checked the fuel press reg and all is golden. ... Mar 30 2022, 09:06 PM Brian Fuerbach
I checked the fuel press reg and all is golden. ... Mar 31 2022, 02:02 PM wonkipop
[quote name='wonkipop' post='2991943' date='Mar 3... Mar 31 2022, 03:30 PM wonkipop [b]@[url=http://www.914world.com/bbs2/index.php?s... Mar 31 2022, 04:30 PM emerygt350 Does that line head into the plenum or the air box... Mar 31 2022, 05:41 PM Brian Fuerbach Wonkipop,
I did read the thread on on the cap. I ... Mar 31 2022, 08:08 PM wonkipop
Wonkipop,
I did read the thread on on the cap. I... Mar 31 2022, 09:23 PM emerygt350 interesting. I assume that PCV system is like the... Apr 1 2022, 06:42 AM Brian Fuerbach
interesting. I assume that PCV system is like th... Apr 1 2022, 01:26 PM wonkipop
interesting. I assume that PCV system is like th... Apr 1 2022, 04:33 PM Brian Fuerbach
interesting. I assume that PCV system is like t... Apr 1 2022, 05:17 PM wonkipop
[quote name='wonkipop' post='2992472' date='Apr 1... Apr 1 2022, 06:11 PM emerygt350 No, no fuel cut on the djet, but I found the rich ... Apr 1 2022, 06:15 PM wonkipop
No, no fuel cut on the djet, but I found the rich... Apr 1 2022, 06:21 PM wonkipop
No, no fuel cut on the djet, but I found the rich... Apr 1 2022, 06:42 PM Van B You guys just aren’t willing to talk about spark... Apr 1 2022, 06:39 PM wonkipop
You guys just aren’t willing to talk about spar... Apr 1 2022, 06:47 PM Brian Fuerbach
You guys just aren’t willing to talk about spa... Apr 1 2022, 07:25 PM wonkipop
[quote name='wonkipop' post='2992522' date='Apr 1... Apr 1 2022, 07:38 PM Van B Distributor vacuum is read/pulled from the throttl... Apr 1 2022, 07:05 PM wonkipop
Distributor vacuum is read/pulled from the thrott... Apr 1 2022, 07:24 PM Van B
Distributor vacuum is read/pulled from the throt... Apr 1 2022, 07:32 PM wonkipop
[quote name='wonkipop' post='2992530' date='Apr 1... Apr 1 2022, 07:44 PM Van B
ok.
so i have the distributor bit right.
phew... Apr 1 2022, 07:44 PM wonkipop
ok.
so i have the distributor bit right.
phew... Apr 1 2022, 07:47 PM Van B Right now I have a relay board baking in the oven ... Apr 1 2022, 07:07 PM wonkipop
Right now I have a relay board baking in the oven... Apr 1 2022, 07:51 PM wonkipop that chart was great.
just as a translation device... Apr 1 2022, 08:16 PM Brian Fuerbach
that chart was great.
just as a translation devic... Apr 2 2022, 02:42 PM Van B Yes. AFR is the bottom scale. There are various g... Apr 2 2022, 03:45 PM wonkipop @Brian Fuerbach
although that specific chart has... Apr 2 2022, 06:19 PM |
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