38 dgas dead spot.

[jesusno2]

anyone ever sucsessfully got rid of that weber dead spot? I put a 38 outlaw on my 2.2 and i have messed around with the jetting and timing dialing the mixture screws in like the manual says, but i have a major flat spot right off idle the truck will actually jerk almost die and then take off like a bat outta hell. I am noticing that their is hardly and vacumm coming from the port of the carb and is it possible that their is not enough vacumm to advance the timing? everything thing is working in the distributor like it should.

[datsunaholic]

I found on mine the accelerator pump was putting out WAY too much fuel- causing it to flood on acceleration.

 

WAY too much carb for a 4-cyl, due to it being synchonous. Yeah, it went like a bat outta hell once I was over 2000 RPMs but it was uncontrollable below that, NOT OPTIMAL for a 4X4. I went back to the 32/36 with lean-jet settings. My L18 is jetted for a B210 (1.4) and my L20B is jetted for a Tercel (1.6L ish). I had a 32/36 jetted for a 2.6L Mitsubishi and it was like an on/off switch.

[jesusno2]

funny part is i've put 38's on suzuki samuri engines and never any problems like this it was just a jetting issue i'm wondering if i got a power valve problem. cause it actuall shows signs of being a little lean when it's cold. when i first fired it up before even messing with anything it spit back through the carb a few times. i'm wondering if it could be a power valve/low vaccum combined issue? I'm really unsure on how to create more of a vacumm signal if thats the case. or i could have to big of a pump jet i guess but their list all the 38 to be the same genaric setting? :mad:

[datsunfish]

I more know the 32/36 but how clean are things inside it?A clogged bowl jet will fuck up throttle and then run off vacuum.Hard to say with a synchronous carb.No secondary to investigate.Sounds like its not getting initial fuel squirt then it pulls fuel with vacuum buildup.

I have run holley 32/36 carbs jetted for a ford 2.3 on L18s and all is fine.I find it hard to notice any difference other than efficiency and the smell.

[jesusno2]

yea exactly i've jumped jetting sizes from 40's to 55's and the best i have found as far as clean wise is the 45 idle jets but it still just stumbles right at 1500 rpm almost as if it drops a cylinder for a second. I can see the accel pump shooting gas into the carb so i know it's working.

[datsunfish]

Isnt there a gear between the 2 barrels that is adjustable?Maybe close one down a bit?Still seems to me that if a pair of sidedrafts can be dialed in,why not a dges?What do you run for spark?You should have a matchbox,msd and big wires.

[banzai510(hainz)]

there is a slight dead spot right off idel

I assume its cuase the 2 barrel open up causing a vacuum loss on the smaller motors. But Im not positive.

Esp when on a hill if not reved up it will stall out.

I went back to a 32/36 DGV as a daily driver

But if you say not proplem with a Suzuki motor then I assume acell pump discharge

[jesusno2]

well i have discovered a interesting fact today this truck runs really good with the timing advanced clear to the stops on the distribitor. so this is telling me my distribitor is not advancing fast enough is their a way to get lighter springs to advance my distribitor faster?? this way i don't have to run so much initial timing? I took the bolts out and turned it past the stoppers and it became hard to start. it ran best at full advance clear to the stops.

[yello620]

Is is causing any problems running that much initial advance? Pinging? Backfiring? Anything? Have you had a timing light on it to know how much advance this really is?

 

Jason

[jesusno2]

it's 20+ initial advance revved up i think someones had the oil pump shaft out of it at some time and did not get it put back in right. so it's off a tooth or so

[banzai510(hainz)]

whats the advance at idle?

if you can get it to 10deg then I say its not off a tooth.

[Mark_Z28]

Its not the carb size, my stock L18 in my 710 had a 38 DG on it and it ran better than the stock carb did. No bogging at all even when floored fast off idle in gear. Sounds like you may have found the problem though.

[jesusno2]

i dunno i pulled the distribitor out this evening and i also pulled the valve cover off to check and see if the engine is in time. It's perfectly in time too! I thinking somethings up with the distribitor the mechanical advace works but this other vaccumm canister i got seem's kind sticky. I still am wondering if the port on the carb is pulling enough vaccum to advance the timing.

[banzai510(hainz)]

Jesus.

I would pull the dist just to make sure the weights or the spring didnt fall off.

 

I think on the the vaccume canister just see if it moves. I guess. You could get a vaccum gun to see if theres a hol in it but i assume when the car is running and the dist is spinning it helps in aid if pulling the adv on the dist at idle.

 

But seriously I had one vacuum adv stuck and I could hardly tell the distributor was bad. ZI drove it that way for a long time.

[jesusno2]

i have the distribitor in my hands right now everthing looks legit i even tested out the module in the distribitor itself and it checks out. the canister is garbage though. i'm just thinking if thats not advancing thats why i'm having to run so much initial timing to compensate for that right off idle advance like it's supposed to do when the truck is running. if i pull the vaccumm advance line off the carb i barley get any vaccumm out of the port even when i rev it up and i'm pretty certian that the vacumm advace needs to be hooked up to the carb and not the intake itself correct? this truck has had this issue since i bought it but i figured it was the stock carb running lean. thats why i bought the weber.

[banzai510(hainz)]

jesus

I believe if i understand this is you will get most vaccum at idle. If you Punch the gas you loose vacuum cause your butterflys are opening and it decease the vaccum to the port.

 

be honest I have dome my timming with the port on and off and havent noticed a real diferenc on my L series set up.

 

Since I sassume you have a Z series Nissan motor it could be soemthing else as this is a more emission equip set up. Datsunmike might know more on these. as I dont .

 

My 38DGES ran great when installed right off the bat. Just it was a bit RICH as my valves/Intake manifold were getting black. Jetted for a toyota FJ40 Landcruser

[jesusno2]

yea that was what my carb was setup for since then i have changed out to alot leaner jets according to the weber tech dudes heres a few pics of my setup with the timing up at top dead center.

 

[jesusno2]

i'm pretty sure i got a ignition problem. I just replaced the canister this weekend also it still just misses real bad. the weird part is when i pull a plug wire off the intake side the coil itself launches spark out from the boot to the negitive side of the coil terminal! Its the weirdest thing i ever seen. any one know what a condenser is and a ficd solenoid is and what their pourpose is?? I'm pulling my hair out with this thing. I've even tore half the motor apart to make sure the cam timing and oil pump timing is correct (which it is.)