Hey David! How are ya? I do not know if the cat is functioning. I am still waiting on plates and as soon as I have them I'm off to my neighborhood garage for my sticker and to have the exhaust anlayzed. I've got the car back together and I'm doing a belt service while I wait for the plates.
I think you just need to check for continuity through the AAV. If you can't make a circuit across the two terminals it isn't going to work right. I forget, what was the status of your injectors? Have they been replaced or even cleaned? If not I would suggest you just replace them - especially given what you said about the car sitting for a year.
Back to it after i finish my belt change. Interesting finding, my air metering plate does not have TOP stamped on it...unless it upside down...hmmmmm?
Belts are just about done. Firday it should be running again. So, The O2 sensor is working wandering between .1 and .935. The throttle butterfly is clean and closes completely. The AAV respoonds well to the fridge/oven test but need to check voltage So far I can't find any broken hoses. FV is buzzing away and the engine reponds porly when you unplug it. Cold start injector is operating as should Checking ignition components next and will replace the injectors.
My '85 idles rock-steady at 1000rpm. It's a little lumpy at idle, but does not fluctuate like yours. FWIW my L-jet 928 had a "pulsing" idle very similar until I pulled the O2 sensor and started running it open loop. Then it became nice and steady too, if a little rich. However it you're still running a cat, don't pull the sensor because it's a good way to destroy it and maybe cause a fire. I didn't read the whole thread, but it could be a feedback loop issue.
And herein lays the problem... And here... Usually, the best place to start Often overlooked, but the root of many idle related problems...
FWIW I just got round to re-setting the mixture on my car yesterday (with gas analyser) after changing the injectors (have hardly done any miles since). I checked it at the MOT station where they have properly calibrated kit & I know it was set correctly this time last year. With the new injectors it was running a bit lean & so I had to adjust it up a bit. I suppose that would be expected if you replaced worn injectors with new ones but it shows that if you change the injectors you do need to check the carburation.
My car should be registered very soon so I will have the exhaust analyzed when I go for my inspection to see whats doing. The cat looks good. Still has its inner guts.
I was reading the article below and ran out to check my oil and yes, it smells of fuel so that needs to be changed right away. I took delivery of the car 1 month ago and have been servicing it since. It'll be registered this week and now that the belts are done I have to tackle this rich running condition. Crankcase ventilation tests to come. I still need to check the ignition components and get some new injectors. I wonder if the crankcase ventilation system is gummed up. ARTICLE When an O2 sensor reads rich, the injector or mixture control (MC) solenoid (on feedback carburetors) has a narrow pulse and the exhaust is rich, what are the possible causes? Probably the most common problem here is oil contaminated with fuel. This is usually the result of an underlying problem such as a misfire, a defective positive crankcase ventilation (PCV) system, a dead O2 sensor, a bad coolant sensor, or any condition that causes the engine to run rich. It drives me crazy to see how many techs overlook this obvious problem. First, fuel contamination should have been identified during the initial inspection by sniffing the oil. Second, this is easily tested for with an infrared (gas analyzer). Pulling the PCV when running should not drop the CO by more than 1 percent on a properly functioning system. Third, and probably most important, any engine that has failed emissions probably needs the oil changed! If an engine has been running improperly, fuel will make its way into the crankcase. Do yourself and your customer a favor and change the oil. Sure, you may want to let the PCV system pull the fuel out now that the system is fixed. Just remember that the learned mixture values in the computer will have to constantly change to update, and the car may not run well until these values stabilize. And while rare, a crankcase explosion is possible. PCV systems also can create a rich condition. Remember that the PCV system is a controlled vacuum leak. The PCV system has to carry oil, water and combustion gases out of the crankcase into the intake manifold for reburning. The components that the PCV is expected to evacuate are also the building blocks for sludge. The PCV system is very prone to plugging from this sludge. Make it a habit to service this system on every car in for a tuneup or emissions, or a driveability complaint. You can run a quick check of the PCV system by installing a vacuum gauge on the dipstick tube. How hard is that? Fuel evaporative emission systems are another simple reason many engines run rich. This is another one that drives me nuts. Dont make your job any harder than it already is! Eliminate the easy stuff first. Many of these systems suffered from high failure rates at higher mileage. Diagnosis is simple, just disconnect the evaporative hoses and see if the rich condition improves. How many techs are checking the air filter on the bottom of GM canisters? How many techs are checking the older canister vacuum diaphragms? Some canisters are full of fuel from customers over fueling the tank or parking facing down on a steep slope. Be sure to check for this and educate customers to prevent future problems. High fuel pressure and vacuum-controlled fuel pressure regulators with leaking diaphragms can also cause a rich condition. The leaking diaphragm should have been found in the early inspection phase of diagnosis. When to test fuel pressure is more of a judgment call. This is largely dependent on how hard it is to test. A system with a schrader valve on the rail should be tested right away, but with a TBI unit that takes a half an hour to test, you may want to eliminate some easier possibilities first. The tip off to high fuel pressure and leaking diaphragms is usually an incredibly short injector on-time. Leaking injectors also have a similar effect, except they usually will not affect all cylinders. A cylinder balance test, along with recording the changes for all four exhaust gases, will usually pinpoint leaking injectors. Also running the cylinder balance test at idle and 2500 RPM will help pinpoint this type of problem. The injectors will usually clear up at 2500 RPM because the amount of fuel needed exceeds the leakage. This test is also helpful in diagnosing vacuum leaks as they become less influential at higher air flow. Leaking injectors can be tested with pressure drop testing after confirming that the system drops are not the result of a leaking fuel pressure regulator or the often overlooked check valve in the fuel pump on the delivery side. If rubber lines are available, they can be clamped off to eliminate these problems. At my shop, we had hoped to test for leaking injectors by shutting off the engine and trying to start with the throttle floored (clear flood mode). The clear flood mode is entered when the computer sees wide open throttle (WOT) and less than 400 RPM. We have often been told no fuel is injected in clear flood mode. This is not always true, many manufacturers go to a 20:1 fuel ratio and the car may start. Also, residual fuel in the intake or crankcase may cause the car to start. We have not found this test to be a reliable indicator of injector leakage.
Idle screw reset. to late to start it and make noise now so testing tomorrow. to set the idle do you then make adjustments via the warm air screw bleow the TB to get to 900-1000 rpm?
Although most of it does not apply to the technology (or lack there of) that's used in a 308QV... Servicing of the oil vapor recovery system is part of a major service when done by a competent shop. This is similar to a PCV system...Other than the O2 sensor, our QV's have pretty dumb fuel injection systems. Despite what the article states, a fuel system pressure test can be very revealing when chasing an apparent mixture problem with a CIS-equipped car. You likely have a very simple problem/problems on your hands and the most efficient way to solve it is to start with the basics. I see many cars that come in running poorly; rough idle, fuel in the oil, high HC and CO levels, low CO2 levels. Rarely is "the problem" a single component... There is no (real) point in setting the base idle speed/fixed throttle plate angle in this stage of your diagnostic process, as the root cause (of the richness) has yet to be determined. Although you can, you'll be going through this adjustment again, once "she's in the ball park"... Best, David
To set the idle: Use a small piece of paper & put it between the screw and the stop. Screw the idle screw up till it just grips the paper. Remove the paper & then add one half a turn. Then set the idle at whatever level you want using the air idle screw under the TB. You shouldn't need to touch the idle screw on the throttle mechanism after that. From my experience how well this process works is a really good indicator as to the way everything is working. I've had God's own trouble gettng my car to idle properly in the past (although generally it seemed to be running OK). With a clean throttle body, no air leaks in vacuum lines etc and new injectors setting the idle took less than a minute. Now the thing idles absolutely evenly at under 900 & the engine revs just fall to idle speed and stay there - no silly dipping down a 100 rpm or so & returning up to idle speed when pulling up to junctions etc. No problems of struggling to idle during the warm up cycle either.
First things first, new wires and plugs on the way. Then when I am out of ideas it's off to your shop David.
so there is no vacuum on the oil dipstick. it burns my eyes so much to be in the garage while the door is open and it is running. I cant stand it!!!!!! even after resetting the idel screw2 it will still not drop rpm's to 500 when i close the air screw
the car is on the road now and once it's warm the exhaust smell is gone and it's nice and clean. It still has the fluctuation in idle though and i feel a pulse in the throttle when i am driving the car...a small surge in acceleration.
