Need weber help plz!!!!!

[RatRod25]

Truck: 84 720, Napz 2.4 Weber 32/36DGEV, Comp cam, Doug Thorley header, Head has been gasket matched and shaved.

 

Problem: My truck runs like crap, Every time i floor it it looks like a drive a diesel!! Big huge cloud of black smoke poors out the back! Under medium exceleration a i get a lil black smoke. It bogs at low RPM's and hesitates. Has a dead miss ever now and again. My plugs are full of black soot, if thats how you spell it. I can tun my idle/mix screw all the way in and still drive it. Im thinkin it needs to be rejeted?? What jets to the 32/36 dgev's come with from weber? :confused:

 

Does any body have and good pics as to where the jets are? Or does any body have and thoughts as What could be the problem?? :confused:

 

 

Sry for the long post but im hopefully going to try and get some jets tomarrow and never messed with webers before.

 

Thanks..

[Pacific coast Datsun]

This is the link to the Weber site. Tons of good info & pix there...

http://www.racetep.com/weberX.html

[RatRod25]

This is the link to the Weber site. Tons of good info & pix there...

http://www.racetep.com/weberX.html

 

Cool thanks PCD! That helped a HOLE lot!!

 

Does any body have any pics of how to change the jets??

[banzai510(hainz)]

I wonder if a main jet in the fuel bowl unscrewed itself out?

 

plugs OK? try new ones

 

Float bowl over filling??????Needle valve or sinking float full of gas weighing it down?

[RatRod25]

I wonder if a main jet in the fuel bowl unscrewed itself out?

 

plugs OK? try new ones

 

Float bowl over filling??????Needle valve or sinking float full of gas weighing it down?

 

Plug have less than 500 miles -NGK's-.. Could be over filling but i dono.. is there and easy way of checking? I have a factory electric fuel pump on there i dono how much psi it puts out, Could it be puttin over 3psi?

 

I have a lil know how with carbs, all i know is fuel injection.

[yello620]

Really isnt that hard to change or check the jets in a weber 32/36. Six screws and one small clip on the choke butterfly is all that holds the top of the carb on. Lift the top off carefully, the gasket can be saved most of the time. Now you should be able to see the two main jets in the fuel bowl. You will also be able to check your float adjustment height. You could also take out the float needle and seat and make sure that it looks good. Check your float for a hole on a pan of water. The Racetep.com site should list what jets that motor should have in stock form, might go up a size or two due to your cam.

 

You could also remove the air corrector jets and the emulsion tubes at this time. I dont think that these are your rich problem, but maybe you want to record what is inside while it is apart.

 

Good luck

[RatRod25]

Really isnt that hard to change or check the jets in a weber 32/36. Six screws and one small clip on the choke butterfly is all that holds the top of the carb on. Lift the top off carefully, the gasket can be saved most of the time. Now you should be able to see the two main jets in the fuel bowl. You will also be able to check your float adjustment height. You could also take out the float needle and seat and make sure that it looks good. Check your float for a hole on a pan of water. The Racetep.com site should list what jets that motor should have in stock form, might go up a size or two due to your cam.

Good luck

Ok cool ima take it apart this week end ill take some pics for shits and giggles.. But is there any hidden springs that are gunna fly out and make swear up a storm tryin to find it right? :lol:

[yello620]

The one that likes to fly is the tiny little Clip that holds the choke linkage. I have seen several different styles of clips to hold these too. Some are drilled for a cotter key, some are E-clips, and others. This is item #6 in the diagram on the racetep site.

 

Good luck

[mklotz70]

While you have the carb off, double check that the secondary butterfly is completely closing. I've come across several of these that were not closing. Plays hell with the idle adjust since it's always getting air/fuel.

 

Factory electric pump? Almost guaranteed it's putting out more psi than the weber wants.

 

If you're taking it off, you should looking into getting a rebuild kit while you're at it. Get the number off the site and call the local Baxter's or similar. They're pretty simple to rebuild.

[RatRod25]

While you have the carb off, double check that the secondary butterfly is completely closing. I've come across several of these that were not closing. Plays hell with the idle adjust since it's always getting air/fuel.

 

Factory electric pump? Almost guaranteed it's putting out more psi than the weber wants.

 

If you're taking it off, you should looking into getting a rebuild kit while you're at it. Get the number off the site and call the local Baxter's or similar. They're pretty simple to rebuild.

 

Yeah it a factory one that is mounted to the side of the frame.. But do you think too mich fuel pressure could cause some of my problems?

[mklotz70]

I just realized you have a 720....so that explains the factory electric pump confusion :)

 

In that case...I doubt you're getting too much pressure....but, a bad float or valve will let too much fuel in and it will over flow the bowl and pour raw fuel into the mani. I'm pretty sure you'd be able to see that if you look down the throat of the carb with it running.

[philip1]

make sure your ignition timing is correct you can run as much as 12 deg initial advance. I had a customer with the same truck and the same problems. not enough advance makes the idle too low so you turn it up to make the truck idle and then you are out of the idle circuit. Set the timing then start over adjusting the carb I think you will find it is jetted closer than you think.

[RatRod25]

make sure your ignition timing is correct you can run as much as 12 deg initial advance. I had a customer with the same truck and the same problems. not enough advance makes the idle too low so you turn it up to make the truck idle and then you are out of the idle circuit. Set the timing then start over adjusting the carb I think you will find it is jetted closer than you think.

 

Im gunna try that.. I had it set to almost ten one time and it ran pretty good but i turned it back for fear of fuckin shit up..

[mklotz70]

Since you have a weber...make sure you read the setup closely....it's a bit backwards of most carbs. The goal with the weber is to keep the butterfly as closed as possible. The more it is open at idle, the less vac signal you'll get to the dizzy when you give it gas. You want it to run as slow as possible, then set the air mix for best idle. I did Paula's backwards for a year or so......sure ran a lot better once I read the instructions!!

 

 

If you still question the fuel pressure.....you can get a cheap fuel pressure gauge at harbor freight. Now that I've been reminded that you have a weber.....they are really sensitve to fuel pressure. I've seen a lot of guys running webers with stock mechanical pumps and they don't seem to have a prob....but I have a regulator in Paula's 521.

[banzai510(hainz)]

http://justbrits.com/Articles/TuneWeber.html

 

site also has SU tuning

[RatRod25]

Ok so kinda figured my problem... I have only 60psi in #4 but 130psi in the rest... But i took the carb apart and found a few jets that had #'s on them.. I drew a real crappy pic of the inside.. Its pretty much the fuel bowl.. Those are the #'s i read on the jets.. Is that good or bad or otherwise?

 

 

 

[yello620]

Those mains and idle seem awful small for a 2.4 motor. Visit Racetep.com, they list the sizes that that motor needed before things like a cam install.

http://www.racetep.com/webtechpage.html

 

Lots of info here, but i am certain that your jets are too small. What is your other jet? opposite side of the carb from the 50.. And which side in your drawing is the primary/secondary? I think that the primary is the left, which means that the unlisted jet is very important to how your truck runs.

[banzai510(hainz)]

I have only 60psi in #4 but 130psi in the rest...?????????

 

maybe this is more the proplem ,then the carb?

[RatRod25]

Yeah that is my problem. Lol I forgot to post that I bought another 720 and put my old carb on it. It has the same 2.4. On that truck I can still turn the mix screw all the way in and doesn't affect the motor?? So are my idle jets big and main jets too small?

Edited July 14, 2009 by RatRod25

[RatRod25]

is the choke suppose to be fully open when the motor is hot or mainly closed? My choke is dam near closed when its running and is fully warmed up..:confused:

[banzai510(hainz)]

is it a electric choke???

 

if yes find the wire that goes to it. then adjust the choke by loosen the 3 screw on the round part so if moves the plate more open when warm.

 

if wire missing ght eplate will be closed affecting top end power(blocking the air)

[RatRod25]

Well when truck is fully warmed up at idle my choke is hardly open.. If i open it fully the truck dies out... I tried unscrewing the idle mix screw and turning in the screw all the way and it dies every time i open the choke??

 

Here is a pic of how open my choke is at idle

 

 

[mklotz70]

You've got an air leak somewhere. Could actually be in the carb if you haven't rebuilt it recently.

[RatRod25]

Not rebuilt but i pulled off the top cover too see what size my jets are and did notice that the gasket above the fuel bowl was not installed right from the factory.. it was miss aligned.. I sprayed carb cleaned all over the carb and it didnt do any but im not sure i sprayed in that exact spot...

[Guest kamakazi620]

sounds to me like you have a big air (vacume) leak,i'd start off by rebuilding the weber,while you have the carb off check you intake gasket and all vacume line etc,for leaks.whatever you do DON'T screw in the mixture screw all the way(hard) you can break the tip off the mixure screw and it will be lodge in the carb body(this is very bad carb will be crap) anyway my 2 cents on the matter.