Heres a history of tracking down this problem.

Problem: The same problem everyone else has - 3rd gear WOT and it craps out at roughly 4500 rpm. Only difference, is sometimes I can be in second, mash it and it starts sputtering at roughly the same rpm.

- My idea for a solution: Flush tank, get better fuel pump (holley red) and an FPR with gauge.

Not fixed.

- Another idea: "Hey, maybe its spark, not fuel"

Installed dlidfis, checked all coils, ignitors, etc.

Not fixed, though it starts and idles better.

- Idea: Mechanical secondaries
Checked it out and noticed secondaries were not opening all the way. Maybe 30%. Also noticed that primaries were also not opening all the way, roughly 80%.

- Another idea: Put a different carb on and see what happens then.

It was better, but it still did it.

So, while my carb is off I figure I should fix the secondaries. After playing with it and seeing how everything worked together, I figured out that I needed to add a spacer on the throttle cable so it would be able to pull all 4 open at once.

Thats now fixed, time to put it back on.... But WAIT, the shutter valve (??? - the thing that has a butterfly attached to it in the intake manifold itself. Helps reduce backfires apparently). Anyways that is out also because it was free moving anywhere from 60%-125% open. Yes, it would go too far open. Emissions were removed so I am sure it was just flopping around in there and probably not doing any good. So that was removed also. Well, do you think that solved the problem stated above??? **** no!

It did, however make my engine idle extremely smooth.

So, now tonight I was looking at my bowl levels. The one toward front of car (I believe secondaries) are above the "line" and primaries I couldnt see, but I am gonna go ahead and assume that bowl has too much also.

Also ever since I put my carb back on, the choke doesnt work. I can pull the cable, and it will close the large "choke butterfly" on top but it doesnt rev up like its supposed to.

So here are my questions: What psi should I have my nikki set to? how do you adjust the bowl height? What the **** is wrong with my choke???? Babysitting my car for 10 minutes is not the one thing I was to do every day.

Thanks ahead of time for any help/ideas/comments.

Ian

 

Not sure on the proper PSI.

Adjust fuel level in bowls by adjustiing float bowl level. If you've got a Haynes manual or a FSM, the procedure is outlined in there.

You can close off the choke butterfly and the engine speed doesn't rise? Is that what you're saying? If so, I'd be looking for a vacuum leak. What is the idle speed?

 

I thihnk the psi is like 3-4 and did you ever think of checking your fuel filter? If it is doing it only under load? Check that thing out, they need replaced, well I replace mine once a year, because I don't like a dirty one...

 

Took the words right out of my mouth. Fuel filter would be the first thing to check, but maybe you did and forgot to mention it. I'm sure it would be nice if the solution was something that simple! Good luck.

 

Good idea on the filter replacement. I assumed (not always a good idea, I know) that with a tank flush, new pump and FPR the filter would have been replaced.

 

I have the exact same problem. My fuel filter is less than a week old too. Ignition is fine, pump seems to be fine. Pressure is at 3.5psi, but I'm not sure on the flow rate. It could be down from stock. Ignition is fine and the car idle real smooth. One think that could affect my flow rate for the pump is the pickup tube in the tank. I have a customized tank and I had to cut the pickup tube down. I wonder if I left enough space between the bottom of the tank and the tube end. I'll have to check that next time the tank is near empty.

Now, onto more relevent things. I suggest checking your fuel lines. Mabey one of them got crushed a little (possible but not likely). Other than that, I don't know what to do.

 

I have the pressure on my Sterling carb set at right under 3 psi. Works great with that pressure. On the choke closing the butterflies, there is a rod that hooks the linkage of the choke cable and the throtle linkage. If that is not present for some reason or is disconnected, you would of course not getting any throtle action when pulling out the choke. This is what I'm talking about:

 

OK a little update. That wire is hooked up (above pic) and when I pull the choke cable the choke butterfly (not sure of another name) closes sometimes. Wether it closes or not, the idle does not increase. I did notice also that when I put in that spacer and started it back up the car idled at 3500. I had to mess with the idle speed and air fuel mix screw until it got back down to 900. It seriously idles smoother than it ever had before. I am still messing with the float settings, and figuring that all out. Any other ideas are appreciated. I will go take a pic in a little bit and show you what I am talking about when I say "spacer". Thanks so far.

IanS

 

Here are pics of spacer, and when choke is off and on - engine not running. Sorry for the crappy quality. I had to turn the resolution way down to be able to fit them here.

 

 

Well to answer your question, it has never been there and it also isnt there on my other carb, nor on my friends 85 GS. I am assuming that it goes there. I will put it on there and readjust and see what happens. Thanks

 

OK after you get that part back together like it should, this next thing takes some thinking. The thing you hooked the choke up to, to the throttle plates, and be flipped around sometimes and be very confusing. Make sure that when you pull the choke, that this link pushe's down on that . That small lever that it connects to should be straight below, not towards the front. To correct it, you need to take the throttle plate off (the bottom part) and swing it over. After a few rebuilds you'll get the hang of this.

 

hmm, so maybe my carb has been rebuilt, just not so well. The engine was messed with before I got it and alot of stuff was done half-assed so to speak. Most of my money/time spent was figuring out how to make everything right again. Yeah try removing the rats nest when only half of it is there to start with.

 

cdrads pic tells the story. Your only getting 1/2 throttle, if that. Look on my cardomain site for a pic of right and wrong. I cant get to car domain from work or Id post the link.

And his first pic (choke linkage). Follow the highlighted rod down. Look at that link it connects to. When you pull the choke, that link should move downwards and contact a tab and open the throttle a small amount. Thats your fast idle.

 

Sweet. Thanks carl, and ITS ABOUT TIME lol. Just messin with ya. I may go have to wake the neighbors up playing with car. HMMM........

 

Wait a minute, so if I am getting half throttle, are you saying that I am only getting half fuel? Since my secondaries are opening up to 100% now, by opening them farther it would be closing them again. yes, I am an idiot when it comes to some stuff.

 

Negative good buddy. When that link flops off like that, your pedal travel is limited.

 

OK so that spring thingy in pic is now where its supposed to be. Throttle response is better but the problem is persistent. I looked at the FSM and my float levels are high, but not by very much at all. I thought they were supposed to be in the middle, not at 2/3 like the FSM states. SOOO any more ideas? Should I just take a whole crapload of pics of the carb and post them here? Also I can get a vid of me driving it and you can hear "the noise" that I am talking about if anyone is interested. I can figure out how stuff works if I see it move, but I cant figure out how air and fuel moves inside something I have never taken apart. I would also rather not take it apart.

 

any luck yet man? I know it is not his fuel filter as he has changed that at least 3 times in the last few weeks. Would an exhaust leak at the header manifold make a significant upper rpm power drop? also have ya done the vaccuum test to see if ya have a leak? easiest way i know of is to spray starting fluid around the carb and if idle rises ya got a leak (gurus correct me if im wrong)

 

Well, was it dirty each time? A bad/rusty tank can clog a filter with crap very quickyl.

 

Yeah it was dirty every time. I even flushed it out as best as I could. I didnt want to drop it because last time I had it down (not out) I had a hell of a time getting it back on there. I dont think that the tank itself has all the crap in it I believe its the pickup.

 

Well ask pratch about that. He clogged filter after filter. The tank wazzzz nasty. He changed it and all was well again. Take it down and clean it.

 

what is recommended for cleaning (flushing) a tank?

Toxic_d

 

Never tried it, but I think this is what a lot of people have used.

http://www.por15.com/product.asp?productid=357

 

if ur still bogging at wot in mid to top of 3rd try this. when it starts to bog, back out of the throttle and hold at 3500 for a few seconds then get back in it. if ur then able to wind out 3rd and 4th, then it's definatly fuel starvation, and the first thing to check is the float level, but since u said it's high then it's not that. the stock pump is 2.5-4psi for the stock carb so check pressure if u haven't already done so. next could be volume, disconnect and plug ur fuel return from the carb and see if that doesn't give u more volume. if it still has the stock rubber fuel lines they may have started to collapse. and like others have said, if the tank is full of trash, get it cleaned out.