84 Carbed issues

Outsane · 08-08-2006, 09:51 AM

Recently got an 84 4runner carbed..

it sat for 8 years maybe started up every couple of months..

So I replaced the usuals..
plugs, wires, cap, rotor, changed the oil, filter, fuel filter, ran seafoam in the tank and poured it down the carb, and used lots of carb cleaner to clean things up get some of the gunk off.

the BVSV broke so I routed the vacumn tubes to each other, my understanding i that when the coolant warms up enough it opens the valve, letting the EGR work.

So the problem I'm having is..

At warm up about 15 seconds after start up, it runs great a bit high of an idle but everything feels nice and smooth and clean.

As soon as the engine warms up the idle drops, the car idles like ass.
idle is so low it stalls at times
idle is rough, and normal driving is a bit rough also.

Lots of back firing when I let off the throttle to slow down or shift

the fuel level on the sight glass is right in the middle.\
timging is dead on 5 deg.
deceleration fuel cut switch works
jets seem clean

let me know what you guys think..
thanks in advance

***fustercluck*** · 08-08-2006, 03:10 PM

Look down in the carb's throat and see if fuel is dripping or shooting down the carb. If it is, then the carb needs to be rebuilt. Sitting for that long makes me suspect the carb ought to gone through anyway. Make sure you replace the jets. This a key factor for fuel econ. and horse power.

also, look for vacuum leaks around the base of the carb and the legion of vac tubes the 84's have. That carb runs poorly when not set up right. When it's dialed in, it's a nice ride. Let us know how it goes.

Outsane · 08-08-2006, 03:12 PM

I'll check on the carbs spray.. and i want it to spray correct..

***fustercluck*** · 08-09-2006, 06:58 PM

actually when at idle you should see very little. If you see fuel dripping down or pouring down, that's a sign the carb needs rebuilt. Frankly, I'd rebuild it anyway after sitting that long.

Outsane · 08-10-2006, 07:43 AM

Maybe I'll be able to look at the jets today

I was hoping not to rebuild... I'll have to start looking for another carb to rebuild..

oh and
the truck also backfires alot when off the gas..
and some times diesles..a bit on shut down.

yota_krazy · 08-10-2006, 10:15 AM

incorrect idle speed could cause that, maybe too rich or lean of a mixture? hows your ignition timing?

deserttoy84 · 08-10-2006, 09:18 PM

bump up ur idle a bit. my truck holds at 1500 drops to liek 600 then stabilizes at about 850-900 rpm which is where it should be idling. its prob just ur idle and a little tweakin with the air fuel. try turning it out 1/4 at a time just gotta listen to it.

Outsane · 08-11-2006, 09:15 AM

I need to check the ignition timing..

and I have the idle turned up pretty much all the way...to keep it running, and it still stall on deccelleration

I thought the air fuel was find a long as its in the middle of the sight glass?

***fustercluck*** · 08-11-2006, 02:55 PM

Quote:

Originally Posted by Outsane

I need to check the ignition timing..

and I have the idle turned up pretty much all the way...to keep it running, and it still stall on deccelleration

I thought the air fuel was find a long as its in the middle of the sight glass?

The sight glass is to determine fuel in the bowl. The mixture is regulated by a screw (sometimes/most times capped). It really sounds like you have a metering problem; whether caused by a vacuum leak or poor needle and seat in the fuel bowl. It could be bad jets, but I doubt that's all it is. This carb needs to be gone through, if only to eliminate it as a suspect......

They sure run well when they are built right.

Outsane · 08-11-2006, 03:02 PM

thanks again for the info I hope to be able to eliminate possible issues one by one...

I sprayed carb cleaner all over the carb while it was running and listened for any changes and nothing...

this was a couple of weeks back..

I hoping to get a used weber carb soon off another board, and i would just wait to toss that on but I need to pass cali smog still..

so my plan is to
check the timing
and see if the spray pattern is good..

***fustercluck*** · 08-12-2006, 02:17 PM

let us know what you find....

84sr5yoty · 08-12-2006, 07:03 PM

Quote:

Originally Posted by Outsane

the BVSV broke so I routed the vacumn tubes to each other, my understanding i that when the coolant warms up enough it opens the valve, letting the EGR work.

What? So you have direct vacuum going to the EGR valve? Either that or you have the vacuum lines reversed and you have direct vacuum going to the EGR once the motor is warmed up. This would cause the truck to run crappy as it is warming up......like the problem you're having now.

Disconnect and plug the vacuum line to the EGR valve and see if it runs decent. I think you got the vacuum lines from the BVSV to the EGR mixed up or routed incorrectly.

Outsane · 08-13-2006, 10:55 AM

Quote:

Originally Posted by 84sr5yoty

What? So you have direct vacuum going to the EGR valve? Either that or you have the vacuum lines reversed and you have direct vacuum going to the EGR once the motor is warmed up. This would cause the truck to run crappy as it is warming up......like the problem you're having now.

Disconnect and plug the vacuum line to the EGR valve and see if it runs decent. I think you got the vacuum lines from the BVSV to the EGR mixed up or routed incorrectly.

The BVSV opens up when then coolant gets warm enough and allows the vacumn to flow through. So I jut bypassed the BVSV, so it would be like the coolant was warm enough.

The problem I'm having is at idle not after warm up.. not during.

Outsane · 08-13-2006, 11:08 AM

Quote:

Originally Posted by fustercluck

let us know what you find....

got a few minutes to mess with it..

Timing is dead on 5 deg

When I pull the throttle the gas is spraying well even saw the gas come out of the accell tube. So the jet looks good..

I checked the vacuum switch for the decelerationfuel cut..and its working..

I was going to play with the mixture screw but I mangled the cap a bit and have not been able to get it off...

I updated the first post to make it easier to get the whole picture of whats going on

***fustercluck*** · 08-14-2006, 08:07 PM

well, I guess I'm schtumped. I would prolly have to be there poking and prodding to figure it out.....

maybe take some pics of your set-up withand without aircleaner. I wish I could look down the throat and see what's going on in there...

Outsane · 08-15-2006, 12:57 PM

too bad you live soo far away..

***fustercluck*** · 08-15-2006, 01:17 PM

6 hrs from Phoenix to SD right?

Outsane · 08-15-2006, 01:29 PM

something like that.. you coming through?

4runnermt · 08-15-2006, 02:35 PM

Sounds like you may be getting too much fuel? Or you have leaky carburetor gaskets? I would rebuild the carb for sure. A kit is probably only 25 bucks at any parts place. Then I'd check all of the vacuum lines. Are the spark plugs wet, or fouled? Does it smoke when its running bad?

***fustercluck*** · 08-15-2006, 04:04 PM

Quote:

Originally Posted by Outsane

something like that.. you coming through?

Coming through in December on the big Fuster family vacation. If you still have the problem I'd like to fiddle with it.

Outsane · 08-16-2006, 12:15 PM

supposed to get this thing smogged this month...

so I hope its all fixed by then..

I may toss on a weber carb, I'm getting for cheap and see if I pass visual and sniff with that..

but either way it would be great to have you look at in dec.

08-08-2006, 09:51 AM	#1 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	84 Carbed issues Recently got an 84 4runner carbed.. it sat for 8 years maybe started up every couple of months.. So I replaced the usuals.. plugs, wires, cap, rotor, changed the oil, filter, fuel filter, ran seafoam in the tank and poured it down the carb, and used lots of carb cleaner to clean things up get some of the gunk off. the BVSV broke so I routed the vacumn tubes to each other, my understanding i that when the coolant warms up enough it opens the valve, letting the EGR work. So the problem I'm having is.. At warm up about 15 seconds after start up, it runs great a bit high of an idle but everything feels nice and smooth and clean. As soon as the engine warms up the idle drops, the car idles like ass. idle is so low it stalls at times idle is rough, and normal driving is a bit rough also. Lots of back firing when I let off the throttle to slow down or shift the fuel level on the sight glass is right in the middle.\ timging is dead on 5 deg. deceleration fuel cut switch works jets seem clean let me know what you guys think.. thanks in advance Last edited by Outsane : 08-13-2006 at 11:08 AM.

08-08-2006, 03:10 PM	#2 (permalink)
*fustercluck* Sponsoring Member Join Date: Sep 2004 Location: Utah :hillbill: Posts: 6,288	Look down in the carb's throat and see if fuel is dripping or shooting down the carb. If it is, then the carb needs to be rebuilt. Sitting for that long makes me suspect the carb ought to gone through anyway. Make sure you replace the jets. This a key factor for fuel econ. and horse power. also, look for vacuum leaks around the base of the carb and the legion of vac tubes the 84's have. That carb runs poorly when not set up right. When it's dialed in, it's a nice ride. Let us know how it goes. __________________ War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself. John Stuart Mill English economist & philosopher (1806 - 1873)

08-09-2006, 06:58 PM	#4 (permalink)
*fustercluck* Sponsoring Member Join Date: Sep 2004 Location: Utah :hillbill: Posts: 6,288	actually when at idle you should see very little. If you see fuel dripping down or pouring down, that's a sign the carb needs rebuilt. Frankly, I'd rebuild it anyway after sitting that long. __________________ War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself. John Stuart Mill English economist & philosopher (1806 - 1873)

08-10-2006, 09:18 PM	#7 (permalink)
deserttoy84 Registered User Join Date: Feb 2006 Location: san diego Posts: 848	bump up ur idle a bit. my truck holds at 1500 drops to liek 600 then stabilizes at about 850-900 rpm which is where it should be idling. its prob just ur idle and a little tweakin with the air fuel. try turning it out 1/4 at a time just gotta listen to it. __________________ 1984 toyota sr5 4x4 22r w/ weber 32/36 Pro comp 4" front springs and 3" rear downey springs D-tech Shocks 33x12.5 M/T , 15 inch weld rims Hella 550/ Hella h4 conversions with HID Home made On-board air system

08-11-2006, 03:02 PM	#10 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	thanks again for the info I hope to be able to eliminate possible issues one by one... I sprayed carb cleaner all over the carb while it was running and listened for any changes and nothing... this was a couple of weeks back.. I hoping to get a used weber carb soon off another board, and i would just wait to toss that on but I need to pass cali smog still.. so my plan is to check the timing and see if the spray pattern is good.. __________________ 1984 4runner - Photography

08-08-2006, 03:12 PM	#3 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	I'll check on the carbs spray.. and i want it to spray correct..

08-10-2006, 07:43 AM	#5 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	Maybe I'll be able to look at the jets today I was hoping not to rebuild... I'll have to start looking for another carb to rebuild.. oh and the truck also backfires alot when off the gas.. and some times diesles..a bit on shut down.

08-10-2006, 10:15 AM	#6 (permalink)
yota_krazy Registered User Join Date: Jul 2005 Location: Seattle, WA Posts: 137	incorrect idle speed could cause that, maybe too rich or lean of a mixture? hows your ignition timing?

08-11-2006, 09:15 AM	#8 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	I need to check the ignition timing.. and I have the idle turned up pretty much all the way...to keep it running, and it still stall on deccelleration I thought the air fuel was find a long as its in the middle of the sight glass?

08-12-2006, 02:17 PM	#11 (permalink)
*fustercluck* Sponsoring Member Join Date: Sep 2004 Location: Utah :hillbill: Posts: 6,288	let us know what you find.... __________________ War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself. John Stuart Mill English economist & philosopher (1806 - 1873)

08-14-2006, 08:07 PM	#15 (permalink)
*fustercluck* Sponsoring Member Join Date: Sep 2004 Location: Utah :hillbill: Posts: 6,288	well, I guess I'm schtumped. I would prolly have to be there poking and prodding to figure it out..... maybe take some pics of your set-up withand without aircleaner. I wish I could look down the throat and see what's going on in there... __________________ War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself. John Stuart Mill English economist & philosopher (1806 - 1873)

08-15-2006, 12:57 PM	#16 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	too bad you live soo far away.. __________________ 1984 4runner - Photography

08-15-2006, 01:17 PM	#17 (permalink)
*fustercluck* Sponsoring Member Join Date: Sep 2004 Location: Utah :hillbill: Posts: 6,288	6 hrs from Phoenix to SD right? __________________ War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself. John Stuart Mill English economist & philosopher (1806 - 1873)

08-15-2006, 01:29 PM	#18 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	something like that.. you coming through? __________________ 1984 4runner - Photography

08-15-2006, 02:35 PM	#19 (permalink)
4runnermt Contributing Member Join Date: Dec 2005 Posts: 501	Sounds like you may be getting too much fuel? Or you have leaky carburetor gaskets? I would rebuild the carb for sure. A kit is probably only 25 bucks at any parts place. Then I'd check all of the vacuum lines. Are the spark plugs wet, or fouled? Does it smoke when its running bad?

08-16-2006, 12:15 PM	#21 (permalink)
Outsane Registered User Join Date: Jun 2006 Location: San Diego Posts: 136	supposed to get this thing smogged this month... so I hope its all fixed by then.. I may toss on a weber carb, I'm getting for cheap and see if I pass visual and sniff with that.. but either way it would be great to have you look at in dec. __________________ 1984 4runner -