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89 Tercel Automatic Weber Carb Swap

3343 Views 2 Replies 3 Participants Last post by  fspmx6
Hey Guys,

I know there have been a lot of posts in the past about this weber carb swap....and I've read most of them....but I can't find what I'm looking for so I thought I'd start a new thread.

I have a 1989 Tercel coupe with 73,000 miles. I finally got tired of putting up with the hesitation and bucking from the old carb and bought the Weber kit 751. Yes...the directions are pretty generic. I've got the old carb off. The thing I'm having problems with are:

1) I think there were a total of 4 electrical wires I have to cut. I know I need the black one or the choke but what do I do with the others? Just tape them off?

2) I've read some posts about the throttle linkage being on the passenger side and some say the drivers side. I have an automatic tranny and have 2 cables connected to the old linkage. Not sure what I do there.

3) Did anyone keep their fuel canister connected?

4) There's that metal rack of lines that run around the front that the vacuum lines connect to. I'm thinking with a little tracing I can remove that whole thing.....any thought?

5) And last...does anyone have any pics of the finished job so I can see what you did?

Any help you can offer will be appreciated!

Thanks,

Bob
1 - 3 of 3 Posts
1) I think there were a total of 4 electrical wires I have to cut. I know I need the black one or the choke but what do I do with the others? Just tape them off?

I just disconnected all the connectors (didn't cut anything) and tied them back out of the way. However, I did run a power line to the electric choke. In my case I just connected it to a fuse that has power with key on. This way it doesn't drain the battery and I have choke for the first min or so until it opens up. If you have an electric coke control you migh as well use it. Just make sure it still functions with everything else disconnected and is not leaving it closed all the time.

2) I've read some posts about the throttle linkage being on the passenger side and some say the drivers side. I have an automatic tranny and have 2 cables connected to the old linkage. Not sure what I do there.

On mine, 1988 Sedan 3E 1.5L Auto (US model), the stock controls were on the drivers (left) side. The webber I used had the controls on the same side (they do make reverse webbers). I removed the cable attachment bracket from the stock carb and bolted it on the webber shaft (perfect fit). However the alinement with the cable mount was off about a half inch. I drilled out the cable mount (attaches to the head) to shift over the cables to line up with the carb. Both cables (accel and shift down) adjusted properly and no other mods were needed.

3) Did anyone keep their fuel canister connected?

Yes I did but do not recall where it was connected. I don't think I used any of the vac hook ups except the three on the heat riser (between the manifold and adaptor). One went to the, oh I can't think of the name right now, the do-hicky that sits on the valve cover and rattles when you shake it (were the factory connection was), PVC valve thats it. Not sure on the others, the Distrubitor is tee'd (dual ports) and run to the back of the carb. Would have to look beyond that.

4) There's that metal rack of lines that run around the front that the vacuum lines connect to. I'm thinking with a little tracing I can remove that whole thing.....any thought?

Chuck it. I have mine sitting in a box with the old carb you only need like three vac lines. Do pick up new vac hose though, most of mine cracked or desinagrated when I disconnected them.

5) And last...does anyone have any pics of the finished job so I can see what you did?

I can get some. Drop me a line at errinh22 (at) gmail (dot) com and I will shoot some over. I don't check it daily so it may be a day or so before you hear back.

The main problem I had was it was running to lean and burning up the valves (two valve jobs in 12 months). While I do not claim to be an expert I did take to the time to research the issues and come to the conclusion you must not have any vac leaks and set the air/fuel mix properly. If the engine gets into a lean condition it will take out the valves fairly quick (heat issues with the head cooling) and is not as forgiving as other designs. I was also shooting for milage. I commuite 125 miles every day and did this when gas was $4 a gallon. I average 33 - 35 MPG running 70 MPH. That said here are a few other things I did;

I used the old base plate (heat riser, the one that has three vac ports on), Thus I had to replace the kit bolts (to short). The back two can't stick up and you must use bolts or cut off anything above the nut if you use the factory studs.

Use thread lock on the 4 little alen head screws for the square plate that the carb bolts to (between adaptor and carb). Mine came loose twice.

I replaced the papper thin gaskets that came with my kit and used fle-pro papper (cut my own) in place of them (no gasket sealers used).

Do not try to use studs for the carb (use kit alen head bolts or hex bolts of equal lenght). Studs will cause the corners of the square plate to raise up and create a vac leak.

Use lock washers on the carb bolts. I used the kind with the lock part on the inside (round on the outer edge and rough in the inside).

I read that the fuel pump my have issues with the webber (or vis-ver-a) I didn't have any issues and just ran a new fuel line (old one is to short).

Jetting, I can supply some numbers that will get you close enough to adjust the carb properly (at least it did on mine), plus since I didn't need the ox sensor any more I used it moniotr the air/fuel mix during setting idle mix. These should get you right in the mid range of the webber adjust settings provided you don't have other issues,

Primary Idle - 55, Primary Main - 140, Primary Emulsiom - F50, Primary Corrector - 170
Secondary Idle - 50, Secondary Main - 140, Secondary Emulsion - F50, Secondary Corrector - 160

Lastly, I didn't care for the tiny little air filter that comes with the webber (little square one), and built up an adaptor that hold a larger round air filter from some aluminum plate. You will see it in the pics. Besides it plugging up every few months, I wanted the engine to be able to breath.
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1) I think there were a total of 4 electrical wires I have to cut. I know I need the black one or the choke but what do I do with the others? Just tape them off?

I just disconnected all the connectors (didn't cut anything) and tied them back out of the way. However, I did run a power line to the electric choke. In my case I just connected it to a fuse that has power with key on. This way it doesn't drain the battery and I have choke for the first min or so until it opens up. If you have an electric coke control you migh as well use it. Just make sure it still functions with everything else disconnected and is not leaving it closed all the time.

2) I've read some posts about the throttle linkage being on the passenger side and some say the drivers side. I have an automatic tranny and have 2 cables connected to the old linkage. Not sure what I do there.

On mine, 1988 Sedan 3E 1.5L Auto (US model), the stock controls were on the drivers (left) side. The webber I used had the controls on the same side (they do make reverse webbers). I removed the cable attachment bracket from the stock carb and bolted it on the webber shaft (perfect fit). However the alinement with the cable mount was off about a half inch. I drilled out the cable mount (attaches to the head) to shift over the cables to line up with the carb. Both cables (accel and shift down) adjusted properly and no other mods were needed.

3) Did anyone keep their fuel canister connected?

Yes I did but do not recall where it was connected. I don't think I used any of the vac hook ups except the three on the heat riser (between the manifold and adaptor). One went to the, oh I can't think of the name right now, the do-hicky that sits on the valve cover and rattles when you shake it (were the factory connection was), PVC valve thats it. Not sure on the others, the Distrubitor is tee'd (dual ports) and run to the back of the carb. Would have to look beyond that.

4) There's that metal rack of lines that run around the front that the vacuum lines connect to. I'm thinking with a little tracing I can remove that whole thing.....any thought?

Chuck it. I have mine sitting in a box with the old carb you only need like three vac lines. Do pick up new vac hose though, most of mine cracked or desinagrated when I disconnected them.

5) And last...does anyone have any pics of the finished job so I can see what you did?

I can get some. Drop me a line at errinh22 (at) gmail (dot) com and I will shoot some over. I don't check it daily so it may be a day or so before you hear back.

The main problem I had was it was running to lean and burning up the valves (two valve jobs in 12 months). While I do not claim to be an expert I did take to the time to research the issues and come to the conclusion you must not have any vac leaks and set the air/fuel mix properly. If the engine gets into a lean condition it will take out the valves fairly quick (heat issues with the head cooling) and is not as forgiving as other designs. I was also shooting for milage. I commuite 125 miles every day and did this when gas was $4 a gallon. I average 33 - 35 MPG running 70 MPH. That said here are a few other things I did;

I used the old base plate (heat riser, the one that has three vac ports on), Thus I had to replace the kit bolts (to short). The back two can't stick up and you must use bolts or cut off anything above the nut if you use the factory studs.

Use thread lock on the 4 little alen head screws for the square plate that the carb bolts to (between adaptor and carb). Mine came loose twice.

I replaced the papper thin gaskets that came with my kit and used fle-pro papper (cut my own) in place of them (no gasket sealers used).

Do not try to use studs for the carb (use kit alen head bolts or hex bolts of equal lenght). Studs will cause the corners of the square plate to raise up and create a vac leak.

Use lock washers on the carb bolts. I used the kind with the lock part on the inside (round on the outer edge and rough in the inside).

I read that the fuel pump my have issues with the webber (or vis-ver-a) I didn't have any issues and just ran a new fuel line (old one is to short).

Jetting, I can supply some numbers that will get you close enough to adjust the carb properly (at least it did on mine), plus since I didn't need the ox sensor any more I used it moniotr the air/fuel mix during setting idle mix. These should get you right in the mid range of the webber adjust settings provided you don't have other issues,

Primary Idle - 55, Primary Main - 140, Primary Emulsiom - F50, Primary Corrector - 170
Secondary Idle - 50, Secondary Main - 140, Secondary Emulsion - F50, Secondary Corrector - 160

Lastly, I didn't care for the tiny little air filter that comes with the webber (little square one), and built up an adaptor that hold a larger round air filter from some aluminum plate. You will see it in the pics. Besides it plugging up every few months, I wanted the engine to be able to breath.
Basically everything I learned when I did mine, almost to the letter. I'll have to check my jetting again, though that sounds very close to what I have in it. However, I found that having both primary and secondary main jets the same, it was running a little too lean at idle and partial throttle. I ended up going up a size or two on the primary, which solved the lean problem, and down the same on the secondary, which kept it from going too rich at WOT.
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