Jump to content
Ultimate Subaru Message Board

Weber tuning questions - please read if you have a Weber!


Recommended Posts

All,

 

This is for a 1980 EA71 Brat.  Shouldn't matter but I wanted to put it out there.  Much more traffic here and a lot of Weber swaps.

 

Scenario:

Re-sealed engine and trans.

Non-Kit Weber 32/36 DGEV swap.

Charcoal system and EGR eliminated.

All vacuums capped off.

Electric choke connected to Hitachi leads - hot with ignition.

 

Completed the rebuild and turned the key; the engine fired.  Engine would idle and then die.  Try to rev it and the engine bogs out and dies.  Hard to restart but will and then dies again.

 

I have adjusted the Idle speed per manual and idle mix as well.  Messed with advancing the timing as well.  The choke is opening and albeit getting hot, seems to be working.

 

 

Called Redline and talked to a real piece of work and was given nothing other than, "you didn't buy the kit so it is not jetted for your car".  I said "Ok".  I spoke of my elevation (6,000 ft in Colorado) and he retorted that the float is not set.  I have also read that I need to adjust the choke?

 

 

I understand if this is an ongoing request as I have read through hundreds of threads.  So I ask of you all for some ideas and or pointers to help get the Brat running again.

 

Thanks.

Jon

 

 

Link to comment
Share on other sites

The engine should be able to start and run, if badly, with even wild jetting differences.  It takes a lot of over-richness to make an engine not run, and leanness should be overcome by pumping the throttle (accelerator pump squirting fuel).

 

Did the engine idle decently at first?.  If it did, then the it should continue idling.

 

Are you sure that the fuel pump stays running after the engine starts?

Link to comment
Share on other sites

Got any pictures of your electric choke & where it's wires into By chance ? I just picked up an 86 hatch & had to rebuild the weber because it was siting for years . Got it running & idling but I'm still playing with mixture & idle screws trying to get it to run proper. My choke was also not hooked up when I got it .......

Link to comment
Share on other sites

Dang, I have photographed every single thing on this rebuild and have not for this portion.  I will do so tonight.

 

The Hitachi has a harness that runs to two vacuum devices and I took the harness off of that and made a splice that connected to the choke.  That would be a connector with two blue wires.

 

I am also curious about the fuel delivery as well.  So stumped on this one.

 

For what it is worth I have not done anything crazy with the PCV setup.  It is pretty much stock as I am adapting the OEM filter to the Weber carb.

Link to comment
Share on other sites

I Bet that it has Fuel Delivery issues,

 

either could be the Fuel inlet is connected to the Fuel Return, or the Float is Stuck; 

 

Assuming that the Fuel Pump is Delivering constant flow.

 

Could you post Photos of your Weber Setup? 

 

So we can figure this out.

 

Kind Regards.

There is only one fuel line in (1980 EA71).

 

What is the best way to test the delivery?  Unplug from carb and turn her over?

Link to comment
Share on other sites

I had that exact problem Jeszek beat me to  it..  In my case there was a replacing of the fuel pump before 
I figured out it was the FPCU.  I really don't know much of the gen1 stuff so if you have one I would check that after verifying whether you are gettig enough fuel.  I had to jumper a wire so the pump is on all the time with a key. I also know that it is a hazard in case of an accident but it is not a part you can replace.

Link to comment
Share on other sites

I had that exact problem Jeszek beat me to  it..  In my case there was a replacing of the fuel pump before 

I figured out it was the FPCU.  I really don't know much of the gen1 stuff so if you have one I would check that after verifying whether you are gettig enough fuel.  I had to jumper a wire so the pump is on all the time with a key. I also know that it is a hazard in case of an accident but it is not a part you can replace.

I'll have to look into that - can't replace?  Explain a bit more please.

Link to comment
Share on other sites

Pics as requested.

 

Cap and rotor with wiring to 1 and 3 cylinders.  New plugs by the way.

IMG_4055_zpsf74db4fa.jpg

 

Cap and rotor with wiring to 2 and 4 cylinders.  Also the lead for the choke.

IMG_4056_zpsfa79bb4b.jpg

 

Stock PVC and 2 and 4 wires.

IMG_4057_zps92fed920.jpg

 

Fuel in on the Weber - only hose that is left, lol.  No return.

IMG_4058_zpscb0097a1.jpg

 

Choke wiring.  Tied into the Hitachi vacuum solenoids.  Blue wire from the harness.

IMG_4059_zps137cfe60.jpg

IMG_4060_zpsb7bad546.jpg

 

Passengers PVC vent - stock.  Also you can see the vacuum cap on the distributor.  I have the outside port being used for the carb vacuum.  Unless I am wrong this is advanced.  The other is retard.

IMG_4061_zps8efb5a9a.jpg

 

Again Drivers side PVC - stock and will go to stock airbox.

IMG_4062_zps350a9668.jpg

 

Pic of the one fuel line.  New fuel line I might add.

IMG_4063_zpsbc6ae319.jpg

 

Timing on the cap and rotor set back to middle.  I cannot say if this is stock though?

IMG_4064_zps16aed827.jpg

 

From behind the intake manifold - EGR capped off, as well as the avs

IMG_4065_zpsc6701e31.jpg

 

So,  let me know what ya think.  It has been made mention of the fuel pump.  That might be my plan so far?

 

Thanks.

Jon

 

 

 

Link to comment
Share on other sites

Not fuel pump.. I was referring to my issue with the fuel pump control unit.  I do not know if the gen 1 vehicles had them.  That would be something Moosens might know and Caboobaru  several others probably but those two would be my go to people to find out.  If you dont have one and you still are not getting fuel then its pump or power.

Link to comment
Share on other sites

Fuel pump control units are available for gen 2 brats (the blue box) at Skagit SUBARU. They quoted me 170 bucks for one. You might try them out, they may be able to ship. I know my 82 has a black one and it has a different number of pins. I've been told that one is the same as the Gen 1's not sure though and I've never stock checked that one. Good luck getting one used. I'm sure theyre are a million of them lying around in parts cars but I've had an ad in the wanted section of the forum for quite a while with no luck yet.

Link to comment
Share on other sites

Thanks for the insights in the fuel issues.

 

After
much research again about the fuel issues it appears that I was not
aware of a "safety precaution" that was in place for these old Subies. 
The Ignition switch fires the fuel pump when the key is turned on to
start the engine.  Once the starter is kicked off and the key returns to
the run or on position the alternator takes over the electricity needs
for the pump.  Seeing as how my alternator has been clicking and it is
original I sprung for a remanufactured alternator and a new Accell Super
Stack Coil.  My coil was original as well.  The voltage regulator was
replaced before I got the Squirrel.  So hopefully that should help with
the issue.  I also have a new fuel filter that will be going on.

 

I will get this to work!

 

New coil:

Accelcoil_zpsb7511329.jpg

 

Any further insights into the installation I have posted pics for above?

Edited by O.C.D.
Link to comment
Share on other sites

Well, concerning Weber carbs generally, you have this one running sideways.  Needs to be rotated 90 degrees, either way, to work properly.  Float slosh in these things is a problem even the right way around..

 

Won't work.

 

He's got it on right....that;s not the issue.

 

I think you need a fuel return.....I'll bet the needle can't hold back the pressure of the fuel pushing in.  You could add a "T", right before the carb, with a small line coming out to return to tank.....like the latter factory hitachi setups.

 

Also, the Fuel pump has nothing to do with the Alternator.

 

the fuel pump relay powers the pump when it has a pulse from the negative side of the coil.  That's why it's sometimes shown as "rev sensor" on the wiring diagrahms.....because it senses the engine has "revolutions" when running/sparking so it keeps fuel going.  Engine stops, no more spark from disty = fuel pump off.

Edited by Gloyale
Link to comment
Share on other sites

I am sorry to seem contradictory, but that carb is not on the right way, it needs to be rotated 90 degrees anti-clockwise.  An adaptor will be required, no doubt.  I see that it fits in that position, but thats the wrong way around for a Weber.

 

That said, it has nothing to do with the instant problem..

 

The carb is probably jetted for a 1600cc Ford Cortina. too lean for an 1800cc Soob.  Just to check though, make sure the fuel pump still runs after the starter drop out, and disconnect the electric choke and wire it open (temporarily) to be sure it's not strangeling the engine.  If, after that, it still stalls, take it to a Weber guru, you might require some fiddle with the jetting. 

 

Or, find a copy of John Pasinni's Weber tuning book, the green one, not the red one.

Link to comment
Share on other sites

The orientation looks fine to me.  It's an ea71 so jetting for a 1600 cc should be what's needed.

 

O.C.D., when you say you are using the stock airbox are you talking about the Subaru one or the Weber one? 

 

Do you have a throttle return spring that hooks to the airbox?

 

How are you setting your timing?

Edited by ferox
Link to comment
Share on other sites

I am sorry to seem contradictory, but that carb is not on the right way, it needs to be rotated 90 degrees anti-clockwise.  An adaptor will be required, no doubt.  I see that it fits in that position, but thats the wrong way around for a Weber.

 

That said, it has nothing to do with the instant problem..

 

The carb is probably jetted for a 1600cc Ford Cortina. too lean for an 1800cc Soob.  Just to check though, make sure the fuel pump still runs after the starter drop out, and disconnect the electric choke and wire it open (temporarily) to be sure it's not strangeling the engine.  If, after that, it still stalls, take it to a Weber guru, you might require some fiddle with the jetting. 

 

Or, find a copy of John Pasinni's Weber tuning book, the green one, not the red one.

 

Again O.C.D has the Weber on the correct way. This is a DGV series or right handed weber NOT a DFV which is mounted the other way. The DFV is a mirror image of the DGV.

Link to comment
Share on other sites

O.C.D. do me a favour and test run the engine without the blue wire from the engine harness attached to anything... Just leave it loose... When I fitted my weber this wire would allow the engine fo fire up and then it would promptly die. This was very frustrating but once I disconnected the blue wire everything just worked and it ran perfectly! Do not ask me why, because I have no idea but it is worth a try.

Link to comment
Share on other sites

If there's a Wire that prevents the engine from running, it must be some sort of Fuel cutting circuit, maybe to work like a Fuel Cutting solenoid present on some Carbs; it worth try to run the engine without that wire as Leeroy Suggested.

 

Also I Agree with all the posters above about the Orientation of the Weber Carb, it Looks Fine for me too.

 

I was about to suggest to try running the engine with the Fuel Pump Directly connected to 12V + Power source, bypassing the Car's wiring for a while, in order to see if that way the engine Keeps running.

 

Kind Regards.

Link to comment
Share on other sites

Won't work.

 

He's got it on right....that;s not the issue.

 

I think you need a fuel return.....I'll bet the needle can't hold back the pressure of the fuel pushing in.  You could add a "T", right before the carb, with a small line coming out to return to tank.....like the latter factory hitachi setups.

 

Also, the Fuel pump has nothing to do with the Alternator.

 

the fuel pump relay powers the pump when it has a pulse from the negative side of the coil.  That's why it's sometimes shown as "rev sensor" on the wiring diagrahms.....because it senses the engine has "revolutions" when running/sparking so it keeps fuel going.  Engine stops, no more spark from disty = fuel pump off.

To be honest, and unless I am completely missing something, there was no return line at all.  The only remaining parts were the charcoal setup and that had some vent return lines from the Hitachi but nothing actually returning gas back to the tank?

 

 

 

I am sorry to seem contradictory, but that carb is not on the right way, it needs to be rotated 90 degrees anti-clockwise.  An adaptor will be required, no doubt.  I see that it fits in that position, but thats the wrong way around for a Weber.

 

That said, it has nothing to do with the instant problem..

 

The carb is probably jetted for a 1600cc Ford Cortina. too lean for an 1800cc Soob.  Just to check though, make sure the fuel pump still runs after the starter drop out, and disconnect the electric choke and wire it open (temporarily) to be sure it's not strangeling the engine.  If, after that, it still stalls, take it to a Weber guru, you might require some fiddle with the jetting. 

 

Or, find a copy of John Pasinni's Weber tuning book, the green one, not the red one.

1600 - EA71

 

I will try disconnecting the choke entirely and also wired constant on.

 

Do you have a resource for this "green book"?

 

 

The orientation looks fine to me.  It's an ea71 so jetting for a 1600 cc should be what's needed.

 

O.C.D., when you say you are using the stock airbox are you talking about the Subaru one or the Weber one? 

 

Do you have a throttle return spring that hooks to the airbox?

 

How are you setting your timing?

I have made an adapter plate similar to Idasho's. I want the stock look and the stock PCV routing to be there.

 

Throttle return will be either mounted to the stock airbox or I will weld up a mount.  Haven't made it that far cause it won't run, lol.

 

Timing is a complete mystery to me and I will not lie.  I read and read and read about getting the #1 piston to BTDC and then matching my distributor to that but I cannot seem to figure it out.  I look at the markings on the flywheel but I just don't know when it is BTDC.  Is it during the compression stroke?

 

 

O.C.D. do me a favour and test run the engine without the blue wire from the engine harness attached to anything... Just leave it loose... When I fitted my weber this wire would allow the engine fo fire up and then it would promptly die. This was very frustrating but once I disconnected the blue wire everything just worked and it ran perfectly! Do not ask me why, because I have no idea but it is worth a try.

Are you speaking of the blue wires that I wired the Weber choke into?

 

Do you think this is more than an ignition-hot wire?  Could it be tied to a sensor that might be causing something electrically?

 

I will remove it form the harness and try.

 

 

If there's a Wire that prevents the engine from running, it must be some sort of Fuel cutting circuit, maybe to work like a Fuel Cutting solenoid present on some Carbs; it worth try to run the engine without that wire as Leeroy Suggested.

 

Also I Agree with all the posters above about the Orientation of the Weber Carb, it Looks Fine for me too.

 

I was about to suggest to try running the engine with the Fuel Pump Directly connected to 12V + Power source, bypassing the Car's wiring for a while, in order to see if that way the engine Keeps running.

 

Kind Regards.

When I tried to start her last night I smelled fuel in the carb and I could tell it was new (not from the last time I tried).

 

 

 

 

I really think I am not getting spark now but I am not sure where to start.  The voltage regulator was newer and looked good.  Could I have fried my coil while trying all of these starts? 

 

Where does one start in looking for no spark?

 

Again, she has new plugs, semi-new disty and rotor, semi-new regulator, cleaned up starter.

 

Thank you all so much for helping me!

Link to comment
Share on other sites

Again O.C.D has the Weber on the correct way. This is a DGV series or right handed weber NOT a DFV which is mounted the other way. The DFV is a mirror image of the DGV.

 

Yes, the DGV and DFV are mirror images.  But neither one is intended to run sideways.  If you want to run a Weber in this orientation, you need a small IDF or IDA carb.  I'd start with an IDF 40 and the smallest chokes available and fiddle with it.

 

Both of John Passini's books, red and green, are available on Amazon.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...