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> 1974 1.8L engine fast idle then stalls, Fuel injection issues
tshih914
post Feb 19 2023, 11:45 PM
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My 1.8L 914-4 with stock Bosch L?-Jetronic FI after being stored several years started to develop a hard to start problem. When finally started would stall when I give the gas pedal any input to raise the revs. I suspect there was some kind of intake air leak and while fiddling around had a backfire which blew the AF meter which I had Pelicanparts repaired. After replacing the fuel lines with the stainless ones from Tangerine Racing and flushing out the fuel system with Techron the engine started to run normally for a short time. Now the engine can be started and fast idles at 3000 rpm but again any input to rev up the engine results in stalling. The idle adjustment screw at the base of the throttle housing is fully closed. Any suggestions on how to fix?
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wonkipop
post Feb 23 2023, 12:00 PM
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ok @tshih914

@Van B (i'm sure) and i would like you to do one more test.

pull the AFM plug out (you can pull it out up at the AFM unit on the aircleaner) and see it if starts and runs at this 3000 rpm. don't touch the gas pedal. just let it start on its own.

if it does start and run do a second thing.

turn if off, restart it without touching the gas pedal or throttle and then once its running again at this steady 3000 open the throttle to give it the gas and see what happens. again with AFM plug out.

report back on the result.
-------


thanks for including the photos.
i am studying them trying to look at area between battery and firewall.
it looks like your ECU is not securely fixed but floating around in there.
its been rotated 90 degrees.
not that its necessarily the cause of your problem,
but @Van B (and i) are thinking of your ECU to AFM connection.
the test i have asked you to do is going to see if this is the problem.


-------

i can see from photos how you have rigged up the fuel lines.
looks fine. i can see most of your vacuum lines and they look right and looks like you have gone over them. i can even see the intake runners appear to have new or good condition woven seals. so all that looks pretty good for being tight and leak free.

its a good idea inserting a full flow high pressure fuel filter in the line like you have.
i have one too which i have installed in almost the same spot.
will save your injectors if you have a newer type fuel pump and it detonates internally.

which leads to the next question.

when this problem of more and more difficult starting first was happening, where was the fuel pump and what was it. original type pump under engine bay on rhs? with original electrical connection?

and did you install a new fuel pump with all your work on the fuel lines.
if you did, where is it, what type and how is it wired in to run?
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tshih914
post Feb 23 2023, 07:58 PM
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QUOTE(wonkipop @ Feb 23 2023, 10:00 AM) *

ok @tshih914

@Van B (i'm sure) and i would like you to do one more test.

pull the AFM plug out (you can pull it out up at the AFM unit on the aircleaner) and see it if starts and runs at this 3000 rpm. don't touch the gas pedal. just let it start on its own.

if it does start and run do a second thing.

turn if off, restart it without touching the gas pedal or throttle and then once its running again at this steady 3000 open the throttle to give it the gas and see what happens. again with AFM plug out.

report back on the result.
-------
@wonkipop The fuel pump was left as OEM stock just replaced the old fuel hoses to tank and line to engine.

I unplugged the AFM and the engine started after several attempts and started to idle around 1200 rpm initially then rose to 2000 rpm. Shut it off and upon restart while at 2000rpm try to give it gas it immediately stall. All the while unplugged so no AFM inputs

thanks for including the photos.
i am studying them trying to look at area between battery and firewall.
it looks like your ECU is not securely fixed but floating around in there.
its been rotated 90 degrees.
not that its necessarily the cause of your problem,
but @Van B (and i) are thinking of your ECU to AFM connection.
the test i have asked you to do is going to see if this is the problem.


-------

i can see from photos how you have rigged up the fuel lines.
looks fine. i can see most of your vacuum lines and they look right and looks like you have gone over them. i can even see the intake runners appear to have new or good condition woven seals. so all that looks pretty good for being tight and leak free.

its a good idea inserting a full flow high pressure fuel filter in the line like you have.
i have one too which i have installed in almost the same spot.
will save your injectors if you have a newer type fuel pump and it detonates internally.

which leads to the next question.

when this problem of more and more difficult starting first was happening, where was the fuel pump and what was it. original type pump under engine bay on rhs? with original electrical connection?

and did you install a new fuel pump with all your work on the fuel lines.
if you did, where is it, what type and how is it wired in to run?

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tshih914
post Feb 23 2023, 08:16 PM
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QUOTE(tshih914 @ Feb 23 2023, 05:58 PM) *

QUOTE(wonkipop @ Feb 23 2023, 10:00 AM) *

ok @tshih914

@Van B (i'm sure) and i would like you to do one more test.

pull the AFM plug out (you can pull it out up at the AFM unit on the aircleaner) and see it if starts and runs at this 3000 rpm. don't touch the gas pedal. just let it start on its own.

if it does start and run do a second thing.

turn if off, restart it without touching the gas pedal or throttle and then once its running again at this steady 3000 open the throttle to give it the gas and see what happens. again with AFM plug out.

report back on the result.
-------
@wonkipop The fuel pump was left as OEM stock just replaced the old fuel hoses to tank and line to engine.

I unplugged the AFM and the engine started after several attempts and started to idle around 1200 rpm initially then rose to 2000 rpm. Shut it off and upon restart while at 2000rpm try to give it gas it immediately stall. All the while unplugged so no AFM inputs

thanks for including the photos.
i am studying them trying to look at area between battery and firewall.
it looks like your ECU is not securely fixed but floating around in there.
its been rotated 90 degrees.
not that its necessarily the cause of your problem,
but @Van B (and i) are thinking of your ECU to AFM connection.
the test i have asked you to do is going to see if this is the problem.


-------

i can see from photos how you have rigged up the fuel lines.
looks fine. i can see most of your vacuum lines and they look right and looks like you have gone over them. i can even see the intake runners appear to have new or good condition woven seals. so all that looks pretty good for being tight and leak free.

its a good idea inserting a full flow high pressure fuel filter in the line like you have.
i have one too which i have installed in almost the same spot.
will save your injectors if you have a newer type fuel pump and it detonates internally.

which leads to the next question.

when this problem of more and more difficult starting first was happening, where was the fuel pump and what was it. original type pump under engine bay on rhs? with original electrical connection?

and did you install a new fuel pump with all your work on the fuel lines.
if you did, where is it, what type and how is it wired in to run?


The fuel pump is the original one that came with the car. Its in the front of the car under the fuel tank next to the brake master cylinder protected by the steel panel that,s bolted to the A-arms front torsion bar area.
I unplugged the AFM and the engine started after several attempts and started to idle around 1200 rpm initially then rose to 2000 rpm. Shut it off and upon restart while at 2000rpm try to give it gas it immediately stall. All the while unplugged so no AFM input
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Posts in this topic
tshih914   1974 1.8L engine fast idle then stalls   Feb 19 2023, 11:45 PM
Van B   Check to make sure your AFM is plugged in first.   Feb 20 2023, 01:28 AM
wonkipop   Check to make sure your AFM is plugged in first. ...   Feb 20 2023, 01:38 AM
Geezer914   1+ on the AFM not being connected. Check for vacu...   Feb 20 2023, 06:48 AM
tshih914   1+ on the AFM not being connected. Check for vac...   Feb 20 2023, 11:02 AM
wonkipop   1+ on the AFM not being connected. Check for va...   Feb 20 2023, 02:33 PM
Van B   [quote name='Geezer914' post='3059382' date='Feb ...   Feb 20 2023, 02:51 PM
wonkipop   1+ on the AFM not being connected. Check for va...   Feb 20 2023, 05:11 PM
dr914@autoatlanta.com   for the hell of it check the throttle body boot fo...   Feb 20 2023, 11:17 AM
r_towle   for the hell of it check the throttle body boot f...   Feb 28 2023, 08:57 PM
tshih914   for the hell of it check the throttle body boot ...   Feb 28 2023, 09:13 PM
rhodyguy   Would a vacuum leak down stream of AFM result in a...   Feb 20 2023, 01:22 PM
wonkipop   Would a vacuum leak down stream of AFM result in ...   Feb 20 2023, 02:17 PM
Van B   @wonkipop What alerts me is the no change in idle...   Feb 20 2023, 02:57 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 20 2023, 03:20 PM
Van B   Yeah, I know, but I don’t care about California ...   Feb 20 2023, 03:33 PM
wonkipop   Yeah, I know, but I don’t care about California...   Feb 20 2023, 03:49 PM
jim_hoyland   All the above; L-Jet requires that there are no va...   Feb 20 2023, 03:52 PM
wonkipop   @Van B thinking about his problem there are two ...   Feb 20 2023, 04:13 PM
tshih914   @[url=http://www.914world.com/bbs2/index.php?show...   Feb 22 2023, 07:36 PM
Van B   Boy does that all sound familiar. I’d still lik...   Feb 20 2023, 04:24 PM
wonkipop   Boy does that all sound familiar. I’d still li...   Feb 20 2023, 04:39 PM
porschetub   Boy does that all sound familiar. I’d still l...   Feb 20 2023, 08:34 PM
wonkipop   [quote name='Van B' post='3059531' date='Feb 20 ...   Feb 21 2023, 02:57 AM
Van B   @wonkipop . What he described is exactly what hap...   Feb 20 2023, 06:45 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 20 2023, 06:52 PM
wonkipop   @Van B which is to say as i suspected that high ...   Feb 20 2023, 06:56 PM
Geezer914   Go to Jeff Bowlsby's web site and get the Ljet...   Feb 20 2023, 07:13 PM
JeffBowlsby   You might also check the quality of the contacts i...   Feb 20 2023, 11:58 PM
wonkipop   You might also check the quality of the contacts ...   Feb 21 2023, 03:05 AM
Van B   Whatever you have back there by the batter near wh...   Feb 22 2023, 08:19 PM
tshih914   Whatever you have back there by the batter near w...   Feb 23 2023, 04:46 AM
Van B   Ok. Glad that thing wasn't some decel valve ri...   Feb 23 2023, 05:54 AM
Geezer914   Got rid of all that shit, the decel valve and the ...   Feb 23 2023, 08:45 AM
rjames   Got rid of all that shit, the decel valve and the...   Feb 23 2023, 11:50 AM
wonkipop   Got rid of all that shit, the decel valve and th...   Feb 23 2023, 11:54 AM
rhodyguy   Curious. What kind of condition are the oil fill t...   Feb 23 2023, 11:58 AM
wonkipop   ok @tshih914 [b]@[url=http://www.914world.com/...   Feb 23 2023, 12:00 PM
tshih914   ok [b]@[url=http://www.914world.com/bbs2/index.p...   Feb 23 2023, 07:58 PM
tshih914   ok [b]@[url=http://www.914world.com/bbs2/index....   Feb 23 2023, 08:16 PM
Van B   @wonkipop if the decel valve is full flow, it cou...   Feb 23 2023, 02:50 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 23 2023, 03:58 PM
wonkipop   ok @Van B and [b]@[url=http://www.914world.com/...   Feb 23 2023, 06:50 PM
wonkipop   wow @tshih914 that was a quick test and reply. ...   Feb 23 2023, 09:01 PM
Van B   Definitely sounds like the AFM is doing stuff… b...   Feb 23 2023, 09:41 PM
tshih914   Definitely sounds like the AFM is doing stuff… ...   Feb 25 2023, 04:35 PM
tshih914   Definitely sounds like the AFM is doing stuff…...   Feb 25 2023, 04:36 PM
wonkipop   @tshih914 we are getting somewhere. this time it...   Feb 25 2023, 05:56 PM
Van B   @tshih914 The decel valve is on the other side. ...   Feb 25 2023, 06:45 PM
Van B   Yeah this is all wrong. You’ve got the wrong par...   Feb 25 2023, 06:49 PM
wonkipop   @Van B . i think he has got it right. he seems to...   Feb 25 2023, 07:22 PM
wonkipop   i think he has pulled this hose out and capped the...   Feb 25 2023, 07:26 PM
wonkipop   where i am going with my thinking @Van B is 1. ...   Feb 25 2023, 07:44 PM
Van B   Looks to me then like the decel valve is connected...   Feb 25 2023, 07:54 PM
wonkipop   @Van B . yes i noticed that kink in the small vac...   Feb 25 2023, 08:29 PM
wonkipop   i just watched your video @Van B . your decel is ...   Feb 25 2023, 08:56 PM
tshih914   I have every vacuum hose hooked up the same as the...   Feb 26 2023, 07:57 AM
wonkipop   I have every vacuum hose hooked up the same as th...   Feb 26 2023, 12:53 PM
Van B   I have every vacuum hose hooked up the same as th...   Feb 26 2023, 12:58 PM
wonkipop   I have every vacuum hose hooked up the same as t...   Feb 26 2023, 01:03 PM
r_towle   When I am hunting for a failure in the vacuum syst...   Feb 25 2023, 09:03 PM
Van B   74 L-Jetronic needs the distributor vacuum for any...   Feb 25 2023, 09:19 PM
wonkipop   74 L-Jetronic needs the distributor vacuum for an...   Feb 26 2023, 12:37 AM
nihil44   I've come in late here and haven't read al...   Feb 26 2023, 01:43 AM
wonkipop   I've come in late here and haven't read a...   Feb 26 2023, 01:54 AM
Geezer914   Last resort is to do a smoke test. Search on you ...   Feb 26 2023, 06:12 AM
Geezer914   I had a hell of a time finding a vacuum leak. It ...   Feb 26 2023, 09:39 AM
Van B   Ok so, I checked my AFM to see what I settled on f...   Feb 26 2023, 12:50 PM
wonkipop   ps in addition to blocking off snorkel the only ot...   Feb 26 2023, 12:58 PM
Van B   ps in addition to blocking off snorkel the only o...   Feb 26 2023, 01:00 PM
wonkipop   two suggestions by other members re injector seals...   Feb 26 2023, 01:58 PM
tshih914   two suggestions by other members re injector seal...   Feb 26 2023, 03:23 PM
wonkipop   two suggestions by other members re injector sea...   Feb 26 2023, 03:50 PM
wonkipop   direct link to AA vac hose kit. http://www.autoat...   Feb 26 2023, 03:58 PM
tshih914   direct link to AA vac hose kit. http://www.autoa...   Feb 26 2023, 05:18 PM
wonkipop   [quote name='wonkipop' post='3061145' date='Feb 2...   Feb 26 2023, 06:36 PM
nihil44   Here is the gasket on the AFM connector which wasn...   Feb 26 2023, 05:47 PM
nihil44   I have been pursuing running issues and vac leaks ...   Feb 26 2023, 06:28 PM
wonkipop   love your work @nihil44   Feb 26 2023, 06:39 PM
tshih914   love your work @[url=http://www.914world.com/bbs...   Feb 27 2023, 09:45 PM
wonkipop   love your work [b]@[url=http://www.914world.com...   Feb 28 2023, 02:26 AM
Van B   See the little hole near the front right off the A...   Feb 28 2023, 06:51 AM
tshih914   See the little hole near the front right off the ...   Feb 28 2023, 07:44 PM
wonkipop   See the little hole near the front right off the...   Feb 28 2023, 07:51 PM
tshih914   [quote name='tshih914' post='3061665' date='Feb 2...   Feb 28 2023, 08:47 PM
tshih914   [quote name='tshih914' post='3061665' date='Feb ...   Feb 28 2023, 09:10 PM
wonkipop   [quote name='tshih914' post='3061665' date='Feb ...   Feb 28 2023, 10:40 PM
Van B   Have you adjusted the decel valve or tested it to ...   Feb 28 2023, 08:07 PM
Van B   @wonkipop quit being so scared to that mean AFM. ...   Feb 28 2023, 08:09 PM
wonkipop   [b]@[url=http://www.914world.com/bbs2/index.php?s...   Feb 28 2023, 10:23 PM
Van B   Thats too low IMO. I posted the link to my thread ...   Feb 28 2023, 08:53 PM
Van B   Diaphragm is rubber. It gets hard and less flexibl...   Feb 28 2023, 09:58 PM
wonkipop   @tshih914 i knew i had this filed away but could...   Mar 2 2023, 09:55 PM
wonkipop   here is the rest of it. its an idiots guide. which...   Mar 2 2023, 10:15 PM
tshih914   here is the rest of it. its an idiots guide. whic...   Mar 3 2023, 10:11 PM
tshih914   [quote name='wonkipop' post='3062180' date='Mar 2...   Mar 3 2023, 10:12 PM
tshih914   [quote name='wonkipop' post='3062180' date='Mar ...   Mar 3 2023, 10:13 PM
tshih914   [quote name='tshih914' post='3062427' date='Mar 3...   Mar 3 2023, 10:18 PM
Van B   When you pinch the AAV hose, and the rpm drops to ...   Mar 3 2023, 10:42 PM
Van B   One other thing, I’m not understanding how you j...   Mar 3 2023, 10:43 PM
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