My dual carb EA81 is "hunting" at 60kph speeds. So in 4th thats about 2000rpm. It sort of goes fast then slow etc. Very annoying. They are similar to standard single carbs. Hitachi's of course. Anyone know the reason they would be doing this?

Thanks.

Is your engine running hot?

My brat with a stock, I believe, single barrel hitachi,

and it fluctuates when it's running hot.

So you may be being afflicted by the same thing,

which I have no idea what is causing it.

I believe it may be the excessive heating of the air going

into the engine and the expansion of the air hitting the hot

water crossover causes a fluctuation in the amount of air

entering the engine.

If that's what's happening.

If not, I have no clue.

 

It may be a faulty or dirty jet not pushing enough fuel

into the carb, causing a surge in power when it does push enough fuel

but a drop when it doesn't.

At such a demanding speed, but low rpm's it may not operate with

enough vacuum to get the fuel through the faulty or dirty jet.

 

Just my two bucks from my limited piggybank of knowledge.

 

Torquemaster Twitch

It done it when my thermostat was installed wrong (stupid me, it fell down while bolting it up so it sealed but let plenty of water through) and my engine wouldn't get warm enough to use its fans then. And now I've fixed the thermostat it still does it when its nice and warm.

I don't think its related to heat.

Hi there,

 

It seems like the symptom of my 93 Loyale. I don't know what trans. you have but mine is an AT and the kickdown relay, according to the ECU, is going down south. I have the replacement part coming in tomorrow but I sold the car today...

5sp EA82 D/R Manual, so the box can't have any control over the motor. Has to be either the EA82 disty I stuck in there (timing looks good and steady not all over the place) or my carbies. Wish I had the cash to swap on some webers.

These carbs have soleniods? If it does then that will most likely be your issue. Seems like every car I have ever come across (GM's and japenese Dodge's) with these soleniod carbs, they do exactly what you describe. Soleniods are probably going south.

As in idle cut solenoids? Or what else is the purpose of these "solenoids" that you speak of?

Being that I don't know much about the subie carbs, I would think that they are getting worn and are leaking causing the "hunting" you are describing. That is what happened to my brother in law's dad's japenese dodge truck. Freakin expensive to replace if you are lucky enough to locate the parts.

My dual carb EA81 is "hunting" at 60kph speeds. So in 4th thats about 2000rpm. It sort of goes fast then slow etc. Very annoying. They are similar to standard single carbs. Hitachi's of course. Anyone know the reason they would be doing this?

Thanks.

 

 

Synchronization is paramount w/multiple carbs.I`d be looking there first.You need to check for matched airflow through the carbs at the same part throttle opening w/a unisyn type device. I`d use a higher no load rpm for the measurement in an attempt to duplicate the on road 2000 rpm throttle position/airflow.3000?

Synchronization is paramount w/multiple carbs.I`d be looking there first.You need to check for matched airflow through the carbs at the same part throttle opening w/a unisyn type device. I`d use a higher no load rpm for the measurement in an attempt to duplicate the on road 2000 rpm throttle position/airflow.3000?

 

I totally missed the dual setup DOH!

Synchronization is paramount w/multiple carbs.I`d be looking there first.You need to check for matched airflow through the carbs at the same part throttle opening w/a unisyn type device. I`d use a higher no load rpm for the measurement in an attempt to duplicate the on road 2000 rpm throttle position/airflow.3000?

I sync'ed them pretty good (not with a machine but by ear). It also didn't do it 18months ago in the car I had it in and it did it in the new car before I balanced them.

 

crash321,

Do you mean solenoids or diaphragms?

Carb synching by ear? Good luck w/that.

 

Having owned and maintained several multiple carb cars,IMO,some type of carb balancing tool is essential.

 

Being synched at idle isn`t good enough.You need to know that the linkage opens the throttles equally.

 

Could be,they were OK in your previous installation.A small amount of wear in the linkage is enough to throw them off.

 

W/downdraft carbs,you could check by propping the throttles open(welding rods?) and slowly operating the main linkage.

Both rods should drop at exactly the same time.

Edited February 19, 200917 yr by naru

Everything looks like it works at the identical time.

 

Thinking for now just going with a single weber until I can affrod twins