Another car hesitates/bogs that could be a vac problem

How-to's and repair secrets for your 4WD can be found here. Have a question? Ask it in here!
Post Reply
scotisha
Top Notch Member
Posts: 234
Joined: Thu Jun 22, 2006 9:07 pm
Location: Victoria, BC

Another car hesitates/bogs that could be a vac problem

Post by scotisha »

Hey,

The tercel has started to hesitate and bucks horribly when going up hills. It was fine until a couple of weeks ago after I went down a steep bumpy road (it started to buck on the way back up but once I got to the top of the steep part it was fine). So the bucking only seems to happen on hills, no matter how warm/cold the car is. I have a Weber that was poorly installed so it might have something to do with that :). There also appears to be a vac line that not connected to anything (see pic 1) and I also noticed a cut off tube below the carb on side of the engine (see pic 2, I think that was where the cold air intake went in). The car also seems pretty gutless since the swap but I thought that was because the throttle cable only goes to 75% of full (this will be rectified once I find a welder to weld the original throttle arm together, anyone know a welder in Victoria?, DLB?)
Image
Photo1
Image
Photo 2

I did some reading and found a couple of threads on the topic:
https://tercel4wd.com/forums/viewtopic.php?f=4&t=7796 - 'Vac line attached to nothing' - A vac line not connected to the MC (also has a link to FSM vac-line drawing).
https://tercel4wd.com/forums/viewtopic.php?f=4&t=7960 - 'Car hesitates and stalls on Hill when cold' - Car hesitates on hills and when cold. Was told to check the vac lines and clean the dizzy.
https://tercel4wd.com/forums/viewtopic.php?f=4&t=7745 - 'Weak acceleration, lacking power uphill, occasional backfire' - Same problems I am having (including the occasional backfire) and DLB cleaned the dizzy.
https://tercel4wd.com/forums/viewtopic.php?f=2&t=7251&p=54078 - 'Hesitation when accelerating' - Poor acceleration and could be vac leak ro auxiliary accelerator pump.

So I am planning on:
-Checking the vac lines to see where this random line should go.
--> I just checked and there was another line that connected to nothing. I looked at the vac line drawing and it looks like i have to connect it to the random line. Time to take it for a spin!
-Check the dizzy and give it a cleaning anyways (is there a write-up somewhere? I tried search but no luck)
-Check the aux accelerator pump

In the meantime, can someone easily identify this random line and tell me where I should stick it? :P. And what about that hole in the side of the engine?

Thanks,

Scott
Driver: '86 4wd Tercel Wagon
Fun: '98 BMW M3 sedan

Now I have the best of both worlds!
scotisha
Top Notch Member
Posts: 234
Joined: Thu Jun 22, 2006 9:07 pm
Location: Victoria, BC

Re: Another car hesitates/bogs that could be a vac problem

Post by scotisha »

IMG_20120607_190140 - tercel.jpg
Photo1
You do not have the required permissions to view the files attached to this post.
Driver: '86 4wd Tercel Wagon
Fun: '98 BMW M3 sedan

Now I have the best of both worlds!
scotisha
Top Notch Member
Posts: 234
Joined: Thu Jun 22, 2006 9:07 pm
Location: Victoria, BC

Re: Another car hesitates/bogs that could be a vac problem

Post by scotisha »

So after a quick tour around the block that seems to have fixed things. Time to find a hill and see what comes of it. Looks like the guy who hooked it up connected those two lines together :? ...

I would still like to find out what the hole in the engine is though... and a welder (https://tercel4wd.com/forums/viewtopic.php?f=7&t=6009...

Thanks,

Scotty
You do not have the required permissions to view the files attached to this post.
Driver: '86 4wd Tercel Wagon
Fun: '98 BMW M3 sedan

Now I have the best of both worlds!
User avatar
ARCHINSTL
Goldie Forever
Posts: 6369
Joined: Sat Apr 30, 2005 1:52 pm
My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Re: Another car hesitates/bogs that could be a vac problem

Post by ARCHINSTL »

See this link for a diagram of the Weber: https://tercel4wd.com/forums/viewtopic.php? ... am+#p45435
Also look at the long "Weberiffic" thread staarted by splatterdog.
The "unknown hose" connects to a ported vac source on the Weber; in essence with it unplugged, you have a huge vacuum leak! The hose can't connect to anything, so I'm wondering if it was plugged with something, held on with a clamp and both just somehow fell off?
Except for the orientation of it looking to me like it's always "faced forward," it looks like the right diameter to connect to the VSV which is mounted to the charcoal canister. That has to be it, as nothing else in the vicinity uses a large-diameter hose.
But - if it's there, I can't see the VSV - maybe the installer skipped it and connected the hose directly to the charcoal canister?

The large hole in the manifold cover is for the heated air tube to the OE air filter horn, which is now redundant.
Tom M.
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
User avatar
ARCHINSTL
Goldie Forever
Posts: 6369
Joined: Sat Apr 30, 2005 1:52 pm
My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Re: Another car hesitates/bogs that could be a vac problem

Post by ARCHINSTL »

Wait!
You have a Canadian MT, right? Then you don't have a VSV! Only the AT Canadian cars have it.
So - the charcoal canister has a big line which connects to the fuel tank return and another big one which connects to the ported vac line on the OE carb. This must be what the "unknown line" connects to - unless the installer capped the canister port and stuck a plug in the "unknown line" as mentioned in my previous post.
Tom M.
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
User avatar
dlb
Highest Ranking Member
Posts: 7448
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Another car hesitates/bogs that could be a vac problem

Post by dlb »

hey scotisha. the "vacuum hose to nowhere" should be connected to the lower port on the vacuum advance canister on the bottom of the distributor. it advances the timing during hwy cruising for better fuel economy.

as tom mentioned, the "hole in the engine" isn't anything. that's actually the exhaust manifold and the port is used for the stock carb to feed itself hot air while the engine is cold, but it's not a leak or anything.

i see you still have your charcoal canister. that's the coffee can looking thing behind the carb. i see that it's hooked up wrong though. the skinny vacuum line coming out of the top of the charcoal can should be hooked up to the port just behind the one with the "vacuum hose to nowhere." just remove the brass plug with a flat head screwdriver and put the skinny vacuum line on it.

as for the dizzy, i use the FSM to disassemble them but a quick test to check it is to remove the cap (three 7 or 8 mm bolts) and then try turning the rotor counter clockwise. it should turn just slightly, maybe 5 mm or so, and if you release it it should snap clockwise back to its resting position. this will tell you if the signal rotor is gummed up or not. i would definitely check the ignition timing while you're looking at the dizzy. backfiring is a common sign of incorrect timing.

i would also check the float level of the carb--i had a similar symptom that would occur when going around tight corners and it was because there wasn't enough gas in the float chamber. what little gas was there would slosh to the side and the jets would run dry for a second, causing a momentary loss of power. i actually just wrote up how to check the float level on a weber. here's the thread:

https://tercel4wd.com/forums/viewtopic.php?f=7&t=7872#p57996

once removed, you can check the float by putting it in gas, or water, and seeing if it holds air. if it bubbles, it's bad. also, if you shake it afterward and hear fluid inside it, it's bad. you can get replacements off of ebay for good prices.

i don't think webers have an auxiliary accelerator pump, i think it's just an accelerator pump. the 'auxiliary' part is a cold engine feature that our stock carbs have but webers don't have different cold/hot running systems. that being said, you accelerator pump could be faulty. a few ways to check: with the air filter lid off, shine a flash light down the passenger side barrel of the carb. open the throttle right up. you should see a big spray of gas in that barrel. if not, something is faulty. my weber passed this test but another telltale sign is when, while driving, you give it gas but feel a momentary hesitation before the car starts accelerating. mine did this despite passing the 'squirt' test but after messing around with the accelerator pump when i had the top off the carb, it seems fine now. not sure what i did to fix it, unfortunately.
scotisha
Top Notch Member
Posts: 234
Joined: Thu Jun 22, 2006 9:07 pm
Location: Victoria, BC

Re: Another car hesitates/bogs that could be a vac problem

Post by scotisha »

All right, time for some stupid questions!

1.) Is the 'vacuum advance canister' the round thing with the three ports on the battery-side (right) of the engine below the spark plugs? That is where I hook up the 'vacuum hose to nowhere' See picture.
IMG_20120613_171446.jpg

2.)All the pictures of webers on tercels have all that EGR stuff removed. Can I remove the all that stuff (minus the EGR valve) and just cap all the various lines? And is that air filter okay or should there be a hose there too (I have seen some photos with a line running off it)? See the next picture
IMG_20120613_171529.jpg
As for charcoal canister connection, I unscrewed that plug from that port attached the line from top of the charcoal canister. I am going to have to get a new line though as I had to cut the original because was resting against the engine and got melted :P.

Thanks again for everyone's help!

Scotty
You do not have the required permissions to view the files attached to this post.
Driver: '86 4wd Tercel Wagon
Fun: '98 BMW M3 sedan

Now I have the best of both worlds!
User avatar
dlb
Highest Ranking Member
Posts: 7448
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Another car hesitates/bogs that could be a vac problem

Post by dlb »

1) yup, that's the vacuum advance canister! make sure you attach the "vac line to nowhere" to the lowest port on the vac cans. that's the distributor (aka dizzy) that the vac cans are attached to the bottom of.

2) no, you don't want to get rid of all of that stuff. the thing on the farthest left is the mixture control device (aka MC in the FSM) and it allows a metered amount of air into the intake on sudden deceleration. helps keep the car from backfiring on deceleration. you can remove most of the rest, but if you're not sure what is what i would just disconnect and block the lines that go to the port on the flying saucer-ish face of the EGR. the air filter attached to the top of your valve cover is fine. it can be hooked up via a vacuum hose to the main air filter but the separate little filter does the same job.

i'm in shawnigan. if you want to come up some time i will help you pull all the unnecessary stuff off. send me a PM if you want to do that.
scotisha
Top Notch Member
Posts: 234
Joined: Thu Jun 22, 2006 9:07 pm
Location: Victoria, BC

Re: Another car hesitates/bogs that could be a vac problem

Post by scotisha »

1.) Done! Thanks for the confirmation.

2.) I will take you up on your offer of services! Bye-bye spider lines!

Thanks for the help dlb and ARCHINSTL

S
Driver: '86 4wd Tercel Wagon
Fun: '98 BMW M3 sedan

Now I have the best of both worlds!
Post Reply