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Unread 01-21-2009, 04:15 PM   #31
TripEph
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ok.. i,ll order the parts
how hard is it to change the jets?

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Unread 01-22-2009, 12:51 PM   #32
Fjguercio
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Answered in your PM also... prefer you stay on JeepFourm posts is thats ok, others get to see also.

Please take a look at the WEBER TUNE LINKS & THE MANY LINKS THAT WRITE UP HAS. I recommend you print the TUNE articles/web sites I found. Recommend you read thru them several times and highlighted them on the important points. I kept these article with my WEBER CARB PAPER WORK these Tune Instructions have much more detail than the weber instructions.

You and others hav posted....having to screw the idle screw all the way down, had to clip the spring, all point to the idle jets are too big and when you screw down the progesssion ports open up and lean out the A/F mixture with more air. This needs to be changed or you will wash your cylinder walls with unburnt fuel and contaiminate your oil also. Oil is most likely black and will not lubricate well, change the oil ASAP.

The pictures show the top plate off... there are 5 slotted screws on the top and one bolt holding the carb choke adjust via a bracket, that small bolt needs to come out also. Just fold over the top plate with hoses attached over the valve cover carefully. Even the air filter plate can be folded over the valve cover with out taking off hose. The run jets are in the very bottom of the bowl, they screw in and out.

When you take the top plate off look carefully at the float and the spring location. The float arm pulls down the spring lever to open up the valve seat. Need to verifty this goes back the same way or will not let fuel into the bowl. To help in starting you can fill the bowl 1/2 full with fresh fuel. This will help with the start up.

The idle jets are external to the carb and screw in and out.

All bolts on carb are Metric

When you replace the Top Plate put in on carefully and you will need to rotate the throttle or Choke mechanism so the plate will sit flat. Put in all screws first & bolt. Verify the gasket and top plate sit properly or you can induce a air leak. Then just bottom out screws, go back snug one and go across snug another and go slowly so it sits flat. Then go back and snug a little more and again till tight. Aluminum body don't torque too tight, you may also have to go in and try a different combo.

I would put the smaller jets in primary first... If you have a lead foot all the time you may like the larger jet in primary.

Time to revove the top plate & change jets... 15/20 min
Time to TUNE the carb 15/20min
Reset time and Idle Screw, with smaller idle jets you will see idle rpms go up 500-700 rpms
Fine Tune the Carb one more time
Go for a ride and ck it out.

I bet your stink goes away and will drive much better and fuel economy will be much better. My idea if this works for many of us will as WEBER to ship the Jeep 258 Carbs with the proper jets so not so rich. But this take time and proof.


Fred

Here is a pic of carb with top plate removed from Link Article Above..


I am not the best at paint, first try, but put some lables on it.

Last edited by Fjguercio; 01-22-2009 at 03:42 PM..
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Unread 01-25-2009, 10:13 AM   #33
rj_ton
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Yeah its the same pump. I mounted mine to the frame real close to where the tank is. Just remove the fuel output hose, run a hose from the tank to the pump, then from pump to steel line. Make sure you have the output hose and not the fuel return hose. I got them mixed up on the initial install, idiot. Not a big deal, just a little extra work to fix. Hope this helps,

Cheers
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Unread 01-26-2009, 01:44 PM   #34
TripEph
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the run jets were both 135 from the factory, and the idles were both 55.
I changed out the idles, but i am having a hard time adjusting the idle, and af mixture. it is running a little better, but the idle seems to jump around while just sitting, making it hard to adjust. usually at about 800, then drops to 400/500 and can go up to 1200. Upon hard braking/ stopping it drops low and wants to stall w/o giving it a little gas. also it will stay around 1200-1500 after accelerating, and slowly drops back. any suggestions?
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Unread 01-26-2009, 07:16 PM   #35
Fjguercio
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Quote:
Originally Posted by TripEph View Post
the run jets were both 135 from the factory, and the idles were both 55.
I changed out the idles, but i am having a hard time adjusting the idle, and af mixture. it is running a little better, but the idle seems to jump around while just sitting, making it hard to adjust. usually at about 800, then drops to 400/500 and can go up to 1200. Upon hard braking/ stopping it drops low and wants to stall w/o giving it a little gas. also it will stay around 1200-1500 after accelerating, and slowly drops back. any suggestions?
Are you saying the Run Jets below the float.... they came with 135 jets too small??? The Idles are on the outside 55, are to big. Please Confirm what jet came in your new carb??? And what did you change the Idles/Outside jets to. That large a idle jet means your idle screw is way in most likley. With the idle screw all the way in it opens the throttle plate and progession ports and will really mess stuff up. Your idle spring is a all compressed right??

If you got the extra jets put 147 run and 35 idle and readjust your idle it will most likely go up 500rpms or so with jet change and you willl need to back out the idle screw. Carefully lightly bottom your mixture screw and back out 1.25 to 1.5 turns and try that.

Also make sure your choke closes and opens up properly. Takes a 12V wire if you do not have this hook up will not run right. So leave the aircleaner off so you can verify.

Last edited by Fjguercio; 01-26-2009 at 08:10 PM..
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Unread 01-26-2009, 08:25 PM   #36
Fjguercio
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Try to stay here with your questions for now, Thanks for posting the Jet size on the other Thread. I think that is a good thing.. From what you have looks like they put smaller jets in there.


Quote:
Originally Posted by TripEph View Post
My carb came with run jets 135/135 and idle jets 55/55. I put in 35/35 idle jets.


I left the run jets as 135/135 and cannot put in a 147.5 run because i do not have one.

Also can u please label the idle, mixture, etc screws on one of the pictures. its hard to find a good pic, i just want to make sure im adjusting the correct screws in the correct order.
From what Weber told me the Idle jets supply about 15% of the run circuite.. So when we make the Idle jets smaller the Run jets need to get bigger. Do you have any other run jets?? With this combo 135 are too small.

We could also drill out the 135's if you have full selection of drill bits. The number are metric holes.

I typed wrong prior post its 147 not 147.5 for the run jet. corrected it above.

147/135 = 1.089 does not look like much but that is 9% more fuel
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Unread 01-26-2009, 08:33 PM   #37
TripEph
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Quote:
Originally Posted by Fjguercio View Post
FACTORY SHIPS WITH STD Jets Run 150/147 Primary/Secondary
FACTORY SHIPS WITH STD Jets Idle 65/47.5 Primary/Secondary
This is what was shipped with my carb. This JET SET UP smoked and plugs were black at idle and run.

ORDER:
New Jets Run 135/140 #73840.135 and .140 $5.95 ea

New Jets Idle 40/35/35 # 74404.035 jets Qty 2, one of .040 #74404.040 $6.60 ea
My carb came with run jets 135/135 and idle jets 55/55. I put in 35/35 idle jets.
Quote:
Originally Posted by Fjguercio View Post
If you got the extra jets put 147.5 run and 35 idle and readjust your idle it will most likely go up 500rpms or so with jet change and you willl need to back out the idle screw. Carefully lightly bottom your mixture screw and back out 1.25 to 1.5 turns and try that.
I left the run jets as 135/135 and cannot put in a 147.5 run because i do not have one.

Also can u please label the idle, mixture, etc screws on one of the pictures. its hard to find a good pic, i just want to make sure im adjusting the correct screws in the correct order.
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Unread 01-26-2009, 08:34 PM   #38
TripEph
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here are a couple pics before i put the fpr in... does everything look hooked up right.

the carb runs fine doing anything but idleing???

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Unread 01-26-2009, 08:42 PM   #39
TripEph
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Quote:
Originally Posted by Fjguercio View Post
Try to stay here with your questions for now, Thanks for posting the Jet size on the other Thread. I think that is a good thing.. From what you have looks like they put smaller jets in there.




From what Weber told me the Idle jets supply about 15% of the run circuite.. So when we make the Idle jets smaller the Run jets need to get bigger. Do you have any other run jets?? With this combo 135 are too small.

We could also drill out the 135's if you have full selection of drill bits. The number are metric holes.

I typed wrong prior post its 147 not 147.5 for the run jet. corrected it above.

147/135 = 1.089 does not look like much but that is 9% more fuel
i do have the 140 i ordered, but i didnt think that this would affect the idle??
it seems to run fine in all of the gears, it is just when sitting at idle or slowing to idle that it runs erratic and wants to stall.
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Unread 01-26-2009, 08:42 PM   #40
Fjguercio
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135 Run Jets are too small, in post I used 145(drilled) and 147. I would suggest 147 in both.

Once you get the correct jets or close, will need to go back adust your mix & idle, then ck the time,

You did not mention what happened to Idle when you putin the smaller idle jets.

Did you adjust your mix and idle after you put the smaller idle jets in?? Where are they set?

Take a look at the Spark Plug Reading Link and your plugs will be a little too lean.

return line on your fuel filter needs to be on top on exit, not bottom or side.

The labled jet picture was added above.
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Unread 01-26-2009, 08:52 PM   #41
TripEph
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i will adjust the fuel filter, sorry for being so ignorant on this topic... but i don't understand how the 135 jets that are small affect the idle?
will putting the 140 in primary or secondary help at all or should i order another larger one?
again i'm sorry for all the petty inquiries... i'm just trying to learn a little and maybe save a couple bucks.
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Unread 01-26-2009, 09:08 PM   #42
Fjguercio
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Quote:
Originally Posted by Fjguercio View Post
You did not mention what happened to Idle when you putin the smaller idle jets.

Did you adjust your mix and idle after you put the smaller idle jets in?? Where are they set?

Have you made any of the igntion upgrades discussed, teamrush, grounds??

We can drill out the 135's to 147 with a metric drill bit.
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Unread 01-27-2009, 07:27 AM   #43
Mike Romain
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Quote:
Originally Posted by Fjguercio View Post
Have you made any of the igntion upgrades discussed, teamrush, grounds??

We can drill out the 135's to 147 with a metric drill bit.
I am sorry, but now you are getting right off the wall! DRILL OUT JETS??????

I mean come on, even a pro with a full machine shop isn't dumb enough to go drilling out jets, the flow will never be right. Get the right jet or better get the right carb for the application.

You have to be really careful about running lean also, pistons do burn out. Running that 258 lean enough to get 25 mpg's is right at the edge in my thoughts.
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89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
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Unread 01-27-2009, 09:48 AM   #44
Fjguercio
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Dear Mike Romain,

That is getting to be a bit much.

The Weber 34 run jet are a straight hole, and yes it could be drilled out with correct metric drill bit. I have taken the time to post a picture of the run jet. There are no right angles or chanfers and can be done. I recommend the right jet be ordered but this can be done.

Write UP Suggestes 147 run jets and 35 idle jets..

He ordered (1) 140 run jet and installed two 35 idle jets. Looks like the Weber Factory is now putting smaller jets, Run & Idle in the carb stock. I think the run jets 135 (stock) are too small and suggested he put in 147 Runs just like the write up. He ordered 1 140 jet and I do not think that is going to do him any good.

The 135 run jets from the factory are 8.2% smaller than what I am running.

If you read any of my post information I am getting 24/25 mpg all HWY staight, level, no winds, nice 80 degree day. I was getting 23 mpg in the 1970's with a J2000 Pick Up heavier vehicle and stock tires. The JeepTRuck was 100% stock. My larger tires are like an overdrive, I have a header, better carb, better intake, CDI MultiSpark Ignition, a better coil. I have also posted my leanest conditions hwy driving is still tan but a little leaner than I like. Spring time will be playing and will most likely have 147/147 and now I have est 147/145 (drilled out) and working fine. I have also posted mileage will most likely be 23/24mpg just like yours (23) or is that too lean.

Third time in a day you're ripping on my post... If you are going to rip what I have posted would be nice to aleast read it.





Here is picture of my hwy plugs. Hwy miles, shut off pull over. I want a little richer/more tan for hwy but they look pretty good.


Last edited by Fjguercio; 01-27-2009 at 11:12 AM..
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Unread 01-27-2009, 10:59 AM   #45
Fjguercio
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Quote:
Originally Posted by TripEph View Post
My carb came with run jets 135/135 and idle jets 55/55. I put in 35/35 idle jets.

I left the run jets as 135/135 and cannot put in a 147.5 run because i do not have one.

Also can u please label the idle, mixture, etc screws on one of the pictures. its hard to find a good pic, i just want to make sure im adjusting the correct screws in the correct order.
Dear TripEph,

Mike is kinda right and you do not "read" like the kinda guy that plays with the engine a lot.

Would be best to order 147run jets and 135 idle jets and put them in. It may not be perfect but will be very close and should run well. Do not open the 140 and you can most likley return it or consider a lesson. The jets are only $6 each and not worth not doing it.

After you change the jets will need to adjust your idle, mix, time, go back and adjust fine tune the idle and mix. Idle should be about 700/750

It is also important to have a few things with the ignition changed / upgraded to make any of carbs, BBD, Weber, 2100, holley work well. AS ALL the article said your igntiion needs to running well or you just waiste the extra fuel. I strongly recommend the TEamRush if you have not already done, it gets the spark to the correct location. I would also add a ground 10/12awg to the head, firewall and even a 4 awg wire to frame and starter. I used the ground stud in the hole next to your coil mount. I also add a ground to the DuraSpark Ignition Modual, black wire input/ cut 6" back from connector on the "Jeep Harness" side so stayes in CJ and solder/heatshrink cover a 10/12 awg wire to firewall or battery. DuraSpark gets the ground path from distributor, since you have are rebuild you GUESS painted the distributor hold down fork?? That is one of the ground paths so I removed the paint from the bottom of the fork to help ground after reading JeepHammers info on DuraSpark,TeamRush, Grounding. Just a thought. That could be part of your idle problem and rpms above 1500/2000. Those changes gave me 1000 rpms and 15% peep.

Last edited by Fjguercio; 02-09-2009 at 05:30 PM..
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