Idle Issues

Groesbeck Hurricane · 10-18-2002, 05:59 PM

OK, been gone for awhile. Re-built the motor, couldn’t get the cam timing right. Been driving for two months off and on. Fighting oil leaks, but getting a handle on them. Mainly just needing to re-torque things after driving. I did not touch the CIS during the re-build. No issues with the CIS prior to the re-build and did not add HP items. Just trying to have a nice, easy going 3.0 ’83 SC at the end of the day.

My problem started about six weeks ago. I noticed that the cold idle seemed to not be operating. During warm-up the idle wanted to stay low and the pop-off valve would have an occasional action. The idle was set nicely at 900 RPM when warm. No issues. Last Thursday the idle signature started to change, about the time we received cooler weather. I started diminishing the idle screw to keep the idle low. The screw is now all the way in and the idle is creeping up. My cold start issue is no longer noted, with us having colder (from 70’s to 50’s) in the mornings. Last time I drove the baby, my idle got up to 1600 RPM. I cannot see any binding of the accelerator linkage, but am putting her up and lubing this weekend. Any other ideas? I have replaced hoses but not the oil cap. Could the O2 sensor be a culprit? Cold start idler? Air regulators? Other neat item to get greasy while looking at? Have the weekend to kill.

Also, my wife was transferred to Detroit/Flint area. Does anyone know of a company looking for a great buyer or production planner?

michigan · 10-19-2002, 01:12 AM

David, Suggest you look into an adjustment of the richness on your cis unit. With the weather getting colder, it has to make a difference in how it is set to run and idle. I have had the same type of problems almost on a daily basis here in Michigan.

Superman · 10-19-2002, 06:28 AM

We missed you. You know, I have had experiences with high idle at times and I just noticed something interesting. There is a switch underneath the cruise control cable bracket near the throttle. The throttle linkage is obviously supposed to trigger this switch from below but mine does not return far enough to trigger this switch. I confess I don't know what this switch does. The switch height does not appear adjustable, so I am wondering if my throttle linkage is returning far enough. It seems to me that we sometimes are able to screw the idle screw all the way in and not kill the engine. This would only be the case if the throttle were not closing all the way.

Another thing I noticed is that the arm that does the triggering is not fastened to the linkage tightly. It wiggles a little.

I'd agree that the mixture needs adjusting, but disagree that this should be a recurring problem. Especially the '83, if everything is working and adjusted properly you can drive them from mt mckinley in winter to death valley in summer and never notice any change in engine behavior. But since yours has been disassembled and reassembled, there is almost not question that she needs a fine adjustment. They're finicky about that. Make sure your ignition system is working perfectly when the adjustment is made, using a gas analyzer. New hoses tend to loosen at the clamps. Over time, put a screwdriver on them and make sure they stay snug until they settle in. Same with intake runner nuts. Congratulations.

Groesbeck Hurricane · 10-19-2002, 03:29 PM

I am actually loathe to touch the richness adjustment. It took me a bit of time and patience to get it right last time...

Super, there is an adjustment on the throw arm of the accelerator linkage on the opposite end. If you look where the switch is activated then travel towards the front of the vehicle about two inches you will see a stud with a nut holding it in location. This can be adjusted to increase the throw on your linkage.

I had taken the vehicle to a mechanic to get the cam timing correct. Probably not the best idea. I had found some items it appears to me they had undone, but I am not 100% sure. I do know that I connected the red/wht brown connector to the auxillary air however I found today that the connector was not attached and had been pulled off to the side, under the fan for the heater. I also discovered another and more troubling devolopment. I had worked the oil loss to about one quart per fill up. I got the car warmed up and checked the oil. 156 miles, added two quarts, and needed more. I got underneath and it appears the leaks are coming from between the heads and the case. Think I'm going to have to pull the motor and start over. Hate this, but I had ordered the b/w version of Wayne's book. Need to wait until I find a job and move to Michigan though...

Superman · 10-19-2002, 08:37 PM

Don't get so excited. It could be leaking from an oil return tube, or from a rocker shaft that has worked loose. I'd look at the rocker shafts if it were not obviously the oil return tube. either way, you don't need to remove the motor.

Groesbeck Hurricane · 10-20-2002, 06:51 AM

Super,

Very good advice. My concern is the oil is on the tubes and exchangers and appears to be dripping from above. Everything under 2, 4, 5, 6 appears to be wet with oil. It also appears to be dry from behind the valve rocker shafts. But, as you point out, I should go back and verify that prior to removing the motor.

The seals around the tubes appear to be dry. I will get back under and check the middle of the tubes and see if the middles are leaking. I also note that one of the exhaust studs on 6 has broken off. Interesting. I think there is a small, slight leak at the front seal also. I am getting oil coming up from the crank and being blown back to the top of the motor. The amount of oil appears to be small as only the bottom of the fan is wet and the shelf is dry. I did have leaks at the banjo fittings and the timing chain covers that are now gone. I also have three studs on the lower valve covers that appear to have oil seeping down the stud and through the OEM nut. I know that I will need to replace these nuts. Thanks,

David
Looking for work in SE Michigan as a buyer or planner (shameless plug)

Superman · 10-20-2002, 07:13 AM

Yes, you'll want to track those leaks down as much as possible before you do any engine removing. Most of them can likely be fixed before engine removal. It sounds like your heads are relatively dry but there's lots of oil elsewhere. I think this probably means the wetness is on the case. Leaks from the upper rear (flywheel end) portion of the engine case are not uncommon, particularly if you did not replace the oil thermostat o-ring. Keep looking. Looking and cleaning. Cleaning and looking. This is how you find leaks, whether or not you have to remove the engine to fix them. Find them first, then fix them.

tmctguer · tmctguer's Garage

slightly off topic, but where the heck is Groesbeck, Texas? i'm from the Lone Star state, and i haven't a clue.