Suzuki Forums banner

1 - 20 of 74 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter #1
I have an '86 Samurai that I got about a month ago. I cannot get it to idle right. When it starts up it idles really high, around 3k and then after a bit, goes down to maybe 1.5-2k and when its warm it dropps and putts and almost dies or dies. When driving along or touching the gas it runs great.

I just put a new (used) intake manifold into it cause I broke the old one over-tightening the PCV valve. It still runs almost the same. So I have the new intake manifold in and it seems all good except it is missing one place to plug a vacuum line into. It just doesn't have it, might be an older manifold or something without it. Its the line that comes from the middle of the canister to the manifold below the carb. Should I cap the line or leave it open or ??

Its the middle one in the picture:
 

Attachments

·
Registered
Joined
·
117 Posts
definately cap any vacuum ports that arent being used, as for the really high start up idle its just an adjustment, where the throttle cable hooks on to the carb theres a screw, loosen it a little until it idles where you like. then once warmed up use the idle up screw to make it idle where you like when warm
 

·
Registered
Joined
·
57 Posts
Discussion Starter #3
Wow that worked really well. I adjusted both of those screws and it seems to be working pretty well. However, when its warm, I can rev it high and then pull my foot off the gas and the idle will just drop all the way down and die rather than stopping where I have it set, around 1200rpm. When I rev it it just dies but if i hold it up around 1500rpm for a second then take my foot off the gas it will drop down and idle like its supposed to. Its like it just won't pull the right amount of gas to drop smoothly to an idle. Also, when it idles, it doesn't idle super smoothly but moves around tiny bit, but not terribly bad.

Thanks for your help, it helped a lot. I don't think its vacuum anymore but just the carb.
 

·
Registered
Joined
·
117 Posts
if moving around when idleing that tells me theres a small vaccum leak somewhere...as for the dieing problem theres a syliniod on the carburetor that when you rev it, theres an arm on the syliniod that comes out to bring it smoothly down to idle...if it just dies this tells me that the syliniod isnt working... take the air intake off and rev it and look on the side of the carburetor facing the firewall and see if anything moves... if so it might just be the adjustment on the syliniod... if not then it is in need of replacement... on the stock hitachi carbs however if one thing goes wrong with them i recommend spending the 300 bucks and just getting a weber 32/36 kit from redline and replacing the carb
 

·
Registered
Joined
·
57 Posts
Discussion Starter #5
alright so I tried it out. Is it the circled thing in the picture that you're talking about? When its running, the little rod nipple thing sucks in, and as soon as I turn it off, it comes back out like it is in the picture. It doesn't seem to move at all when I rev it, just stays all the way in when it's running. Not sure if that is right? Also, it wouldn't idle at all with the air cleaner off, don't know if that matters?

Thanks for the help and patients
 

Attachments

·
Registered
Joined
·
57 Posts
Discussion Starter #6
Okay I think I figured it out. When I took the air cleaner off yesterday, I forgot to plug the HIC valve under the cleaner back in. I noticed that when I was looking at that sloinoid and plugged it back in and not it idles! whoooo. So I think thats it? Might have a tiny leak somewhere cause it doesn't idle perfectly smooth, and it has to be around 1200rpm rather than 800 like its supposed to to idle well, but don't think thats a big deal. Now just have to get it smogged :mellow:
 

·
Registered
Joined
·
117 Posts
that was probly the rough idle issue...does it idle down now without stalling? but no the sylinoid that you circled is for the choke..the one i was talking about is on the side of the carburetor
 

·
Registered
Joined
·
57 Posts
Discussion Starter #8
yeah it does for the most part. It was running great and then it did the thing where it fell down and died a couple times, then stopped again and didn't do it until i drove it again after it was cool. Maybe it only does it before its all the way warm? I guess I need to drive it more and figure it out.
Okay, I think I know what you're talking about now. Is it right above where the cable goes where you can pull the throttle with your finger. Looks black rubber with a white point on the end? It would move around when i reved it. Move in when reved then back out more when idling ? Seemed to be working. Unless intermittent?
 

·
Registered
Joined
·
57 Posts
Discussion Starter #10
Alright, I'll just keep messing with it. And run some more carb cleaner through it.
Thanks again for the help, it was very helpful!
 

·
Registered
Joined
·
57 Posts
Discussion Starter #12
Well, its at it again. It won't idle after its warm unless you make it stay at idle with the throttle then let off, and that only works sometimes. It was doing great, I took it to the lake and it crawled on some stuff I didn't think it could do. But now it just won't idle normal.

The only thing I changed was I put this stuff in it that's supposed to make it pass smog called Guaranteed to Pass. Also the little valve that goes between the air cleaner and the intake that has the orange part on it thats supposed to face the air cleaner had the wrong valve on it. It was some bigger white one. I found the one with the orange part on it in the glove box and swapped them out. I don't feel like that should really change idling?
I just want to be able to smog it and have some fun!
 

·
Registered
Joined
·
1,230 Posts
You need the vacuum from the charcoal canister hooked up or you aren't drawing a vacuum on the vapor return line. You can run a "T" fitting off of another vacuum line on the manifold (one that isn't on a switching valve) It's just a pinhole connector on the manifold, so you should use an inline restrictor.

There are two vacuum switching valves that have identical connectors. The front vacuum switching valve that's attached to the timing belt cover has a blue and a black wire going to it. The other vacuum switching solenoid is on the engine side of the carburator and has a brown and a black wire going to that connector. I switched the two up accidentally when I swapped carbs and Had similar problems to the ones you are experiencing.

Also, the last time I got a smog test done, the smog tech tweaked my fuel mixture screw to get it to pass. Unfortunately he did it without telling me. I was running way too lean. To adjust the fuel/air mixture you need to remove the pin from the adjuster port and then using a small straight screwdriver adjust the mixture. Don't do this without an air fuel mixture gauge or a multi meter on your O2 sensor.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #14
Okay cool, I will put the T in the line.

Alright, so I looked at those two sensors with the different color wires and they do seem backward to what you say. However, it looks impossible for them to be switched because they wouldn't reach to switch them as they're bundled together with other wires that go to other senors or back to the firewall.

I adjusted the air/fuel before I read this and it's idling now! But the screw is like three whole turns out, what should it be? How do you measure it with a multi meter? What should it be at?
Thanks for the help!
 

·
Registered
Joined
·
1,230 Posts
you may have the wire cluster routed on the wrong side of the thermostat. If you go on the wrong side you can't reach the connector with the correct plug. I re-grounded the ground wire in that cluster to a different point so It's a stretch for me to even route it on the correct side of the thermostat. Should just be the temperature sensor, a ground wire, and the two Vacuum switching connectors on that part of your wire harness.

I'm not sure what the voltage is supposed to be on the O2 sensor. I have an air fuel gauge on my dash that goes off of the voltage from the O2 sensor. I'll see if I can look it up.

Edit: It looks like it's supposed to run .5 Volts for a stoich reading. (correct air fuel mixture)
 

·
Registered
Joined
·
57 Posts
Discussion Starter #16
Okay so I attached a piture of the upper sensor. In order for them to be switched, someone would have had to mix them up then tape their wires up with a bunch of others to make the harness. Which I guess wouldn't surpise be after seeing some of the stuff previous owners have done to this thing.. I just want to be sure before I go ripping it all apart. I'm really new at electical too, so don't want to push my luck too far.

Okay great, I'll see if I can borrow my buddy's meter and figure it out. That's a lot of help, thank you
 

·
Registered
Joined
·
1,230 Posts
its a pretty tight spread, between .2 and .8 volts so make sure you get an accurate reading.

on the cluster, as I posted earler, it should only be the two VSV connectors, the thermostat temp sender and a ground wire in that cluster. If there's more than that then you probably have an aftermarket tape job.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #18
shoot i forgot to attach the picture on the last post. Sounds pretty obvious though that it's wrong, but I took the picture so might as well use it. So guess I'll switch them around and see how it goes. I only need to switch the electrical plug itself right, not the actual sender/switch right?
 

Attachments

·
Registered
Joined
·
1,230 Posts
OOOH! Glad you posted that pic! I was talking about the front VSV by the timing cover and the solenoid valve on the SIDE of the carburetor. The connector on the side of the carb isn't on the same type of VSV as the rear and the front, its actually on a solenoid that switches the vacuum to a round metal diaphragm can. I'll look up the specific part name and get back to you so you know exactly what I'm talking about.

Edit:
The metal can is called the secondary actuator and is over on the drivers side of the carb towards the front. The connector on it is identical to the one on the front VSV by the timing cover but the color of the wires is different. If you have the two mixed up, you just swap connectors not the valves. That VSV by the pre-EGR on the back of the carb is hooked up correctly.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #20
Oooookay, that makes a lot more sense! I was baffled how the front and back ones could possibly be switched :D
I switched them, as you can see in attached picture (hopefully). Though it doesn't seem to be running much differntly. I even switched them back and started it and I couldn't tell a difference. And I have to have the idle mixture screw backed out about 3 turns to get it to idle (am going to get that multi meter today). Shouldn't it be like 1 1/2 turns out normally?

Hopefully with some fine tuning it'll start purring correctly after switching the connectors. Thanks a lot, I never would have figured that one out!
 

Attachments

1 - 20 of 74 Posts
Top