Question #2 Idle?

[Zorrro]

Question #2:

 

My '87 carbed EA82 has a funny idle. It hunts around and is too low. I turned the idle speed just up just to make it easier to drive. Now that it has turned out to be a good car, I'd like to fix it more better. I have replaced some text-book looking cracked hoses and hosed the entire intake system with starting fluid in search of a leak with no results. The car runs real smooth over 2K RPM but lacks much below that. It is more noticeable on dirt roads and when doing a lot of stopping and starting. It requires some clutch-work, enough to make it smell if your not careful. When off roading it's almost no fun unless you are in low range. I've been getting 21-24 MPG. I removed the egr valve and tested it by sucking where the vacuum hose connects (using my mouth). It seems to open with little effort and close well enough? I've not adjusted any mixture settings on the carb (I suspect no one ever has) and think some part has failed to cause this condition. The auto choke closes completely when cold but still takes 3 tries to start and high idle. The choke opens up when engine has ran a few mins. Any ideas?

 

[Snowman]

Sounds like a full tune-up is in order. Plugs, ignition timing adjustment, idle mixture adjustment, fuel filter, and some fuel system cleaner in the tank may help with this problem. I would try all of that before ripping into anything else.

[Zorrro]

OK. I hope to still get some response as I've tinkered with the car since the last post. The car has acted this way for the last 6,000 miles (it's entire life with me). The plugs have been changed, timimg was at 5 BTDC I just moved it to 9 BTDC. I have run several fuel system cleaners, entire gas tanks (from empty) and drying agents through the tank in that time with no avail? I have one of the Hitachi carbs with no O2 sensor on the Y-pipe. In my Haynes manual I did not see this set-up. Things under the hood look real factory not all hacked-up. I don't know the history of the car. Things could be missing? I looked for the Engine Control Module above the gas pedal and found nothing. The car is an 87 and my Haynes manual claims that 87's are FI only? I bypassed the EGR with a piece of sheet metal. Idle improved slightly but still hunts around at idle. I checked vacuum with a guage and the dist-vac advances OK. Vacuum was slightly low, just outside the normal marks, when measuring at the manifold. The vacuum at the aux componants like the EGR and the Dist Advance was considerably lower. Is this normal? My goal is to keep things as factory as possible , increase gas milage, make cold starting a turn key operation and improve the idle to 2,500 rpm performance. The car runs great other than the idle problem and gets driven regularly for sport and transport.................Thanks, Z

 

 

Oh, yeah. I did a compression test lowest was 132 psi and the high was 140psi. I'm happy with these numbers.

[pyromanic]

Idle hunting Hitache's are a ***************. How'd ya make out on this? I took my antique DGV Weber off for the winter and am back to a "idle hunting Hitache", so I'm curious if this problem got fixed?

 

 

OK. I hope to still get some response as I've tinkered with the car since the last post. The car has acted this way for the last 6,000 miles (it's entire life with me). The plugs have been changed, timimg was at 5 BTDC I just moved it to 9 BTDC. I have run several fuel system cleaners, entire gas tanks (from empty) and drying agents through the tank in that time with no avail? I have one of the Hitachi carbs with no O2 sensor on the Y-pipe. In my Haynes manual I did not see this set-up. Things under the hood look real factory not all hacked-up. I don't know the history of the car. Things could be missing? I looked for the Engine Control Module above the gas pedal and found nothing. The car is an 87 and my Haynes manual claims that 87's are FI only? I bypassed the EGR with a piece of sheet metal. Idle improved slightly but still hunts around at idle. I checked vacuum with a guage and the dist-vac advances OK. Vacuum was slightly low, just outside the normal marks, when measuring at the manifold. The vacuum at the aux componants like the EGR and the Dist Advance was considerably lower. Is this normal? My goal is to keep things as factory as possible , increase gas milage, make cold starting a turn key operation and improve the idle to 2,500 rpm performance. The car runs great other than the idle problem and gets driven regularly for sport and transport.................Thanks, Z

 

 

Oh, yeah. I did a compression test lowest was 132 psi and the high was 140psi. I'm happy with these numbers.

[Zorrro]

So far things are looking better. This morning I had the chance to run to a house down the street. It almost started the first turn. Came up to a nice idle then died out. On the second turn it started and idled. It ran much better cold no giant flat spots between gears. I had only pumped the gas 2x on the first turn. I think if I would have pumped a few more times it would have came right up. This is a major improvement! The temp was just above freezing with snow on the ground. Yesterday I changed both the timing and did the EGR block-off. I have a gut feeling that most of the improvement came from EGR block-off. When I get a chance to make a few trips to work, we will see the "real" improvement. Just by the feel of the new gas-pedal to loco-motion ratio, mileage should be improved. Please do not get me wrong, I believe in clean air. What I do not believe in is 1980's emmission control systems. Corking and engine off is a lame attemp to improve tailpipe emmissions. I will consider a new EGR valve once I determine mileage has been improved by removing the old (possibly bad) EGR. I will also consider what is more important: better mileage or slightly cleaner emmissions and more gas consumption? Still looking for input..............Z

[Subarian]

You don't really need to bother with the EGR valve. Its purpose is to reduce NOx emissions by introducing an inert gas (exhaust) into the combustion chamber when temps theoretically reach 2800 degrees, which is where NOx forms. The truth is, your combustion chamber just isn't getting that hot, because of the design of the engine. So save your money. You might want to invest it in a Weber 32/36. That's what I did when my Hitachi carb finally fell apart (literally). It's been a great upgrade.