alfajeffrey

iTrader: (7)

I just rebuilt the carburator on my series 1. I got it to hold an idle at about 900RPM in drive, but when i go to push down on the accelerator it dies out. I can get it going by holding the brake and feathering the gas. I only drove it about mile with 93 octane.

It has;
new fuel pump and filter
new plugs and wires
new air filter
all vac hoses have been replaced for the most part

I have done a real good job inspecting the vac system

I have the accel pump lever nut tightened almost all the way down, but tried it in several settings with no change

Everything appears to be working properly except the accel hesitation and stall

Any suggestions?

DreamInRotary

iTrader: (49)

I'm no expert, but that sounds to me like a float or jet issue. Did you quadruple check your float level before install? Ensure the jets functioned as they should? You already said you thoroughly checked out the emission system, did you make sure everything was hooked up properly upon reinstallation?

EvilJester

So i was under the impression that is higher the octane the worst the car will run for our carb 12a. Was told to use as low as possible, because the higher the octain the lower the flashpoint/compustability. Which is why turbo/supercharged engines need as high an octain as possible?

alfajeffrey

iTrader: (7)

The carb was as clean as new, and everything got hooked back up properly. The fuel level is about 1 centimeter above the half way mark through the glass. I would think that would be ok.
All the vac hoses are sealed. I was able to get it to idle in drive at about 800, but when I hit the accelerator it would stall. I was able to tune it at 1200rpm and no longer have the accel problems.
I have no idea about needing lower octane. I see the timing for the leading and trailing appear to been changed at some point, and appear to have no effect if i tried changing them. I get very little difference when I rotate the distributor, except when i reach the two sides.

Any advice.

xXGslseSleeperXx

damn, cleaned the carb and still the accel issue! that sucks. And atleast you did all the preventative maintenance so you can rule some things out. i would suggest you get a vacuum gauge hooked in there and tune the mixture screws and timing according to the gauge.(the gauge can tell alot about an engine)(unless you can find someone with an ignition oscilloscope, that will certainly pinpoint a problem) By no means is this gunna fix the accel problem but it will give you a better baseline to work with. Plug the advances when you change the timing also. just my 2 cents! good luck though man! I don't know why but this just sounds like a lean mixture problem to me.

Rx7carl

From your description its the accel pump. That nut should NEVER be screwed down all the way. Back the nut all the way till there's no threads showing. Then while you look down the carb, (air cleaner off of course), adjust the nut so the nozzles squirt AS SOON AS THE THROTTLE IS MOVED. Any delay causes the engine to hesitate and/or die.

alfajeffrey

iTrader: (7)

I disassembled, re cleaned, inspected, and then reassembled. Everything is rebuilt and reassembled properly. I got noticeable response from the mixture and idle adjustments.

I had another carb that was set to stock settings, so I copied its adjustments for the Accel pump.

I can adjust it pretty well, but the only way to keep it from stalling in drive is if the rpms are around 2.5k in park. What happens is when put in drive it dips to 1.5, and begins to pull fuel through the venturi. I had a moment where I had it around 1k in drive, but would die when the gas was pushed.

Still no progress. I am planning on getting a vac gauge this weekend, but will also see if i can find an ignition oscillation.

xXGslseSleeperXx

This is weird! has it ever idled normal or at 800rpm in park?

alfajeffrey

iTrader: (7)

no. I am starting to think I need to eliminate the rats nest, and look for a possible manifold leak. The car only has 40k original, but did have a bad exhaust leak at the block. The heat caused alot of damage to the paint in the surrounding area. I can imagine it would have also cooked that gasket.

Kentetsu

Sounds like you're dealing with an automatic. There might be little items that raise the rpms when engaging a gear, might not be. Someone else can speak up with first hand experience. There are a couple of other weird things with autos that may/may not apply to your car like setting ignition timing in Drive (rather than nuetral) and also maybe the idle speed.

Good luck...




.

alfajeffrey

iTrader: (7)

ya I try setting it in Drive, but with no luck. What are the chances my symptoms are caused by in intake manifold leak? It seems like it is running too rich, but has no power under load.

alfajeffrey

iTrader: (7)

I ended up taking two partial carbs, and putting them into one. I cleaned it out real good, and it fired right up. I appreciate all the help, but that carb must have had more problems than a rebuild kit could help.

This Nikki almost got the best of me, I was surprised to see just how complicated and deceiving the carb can really be. I was about to start tearing all types of stuff off.

One more day in the garage, and my wife probably woulda set her on fire.

xXGslseSleeperXx

SO shes fixed? congrats! yeah they are a pain in the *** sometimes but that is part of the fun. I wonder what went wrong with that carb though? At least you got it straightend out.

alfajeffrey

iTrader: (7)

Ya I dont know. I really appreciate your help along the way. I also gotta thank Jerry AKA Rotaryhaven for giving me the two partial carbs.

I think the three things that may have caused the problems were;

I used thinner to clean with

The needle valves looked to seat differently (one lower than the other)

And; at one time a mixture needle was over-tightened causing some damage to the needle point; I replaced the needle but it may have caused some damage to the housing

xXGslseSleeperXx

No problem! just glad to hear you got it working properly!

Rotaryhaven

iTrader: (17)

His carb was driving me crazy. maybe the over-tightening of the lean rich screw into the carb probably damaged something internally or there was still crud somewhere that wasn't immediately accessible. Thinner is not a good carb cleaner. I didn't know about that. But I am glad that those carbs went to good use. Congrats again.