First of all, did you run the pumps one at a time? There is a link in my reply of Nov 18 that describes how to do this.

This is done with the engine off. Listen. Do you hear them? The tank pump emits a high pitched whine. The main pump sounds like an electric drill. The revs should be constant.

Do this. What are you hearing?

Second of all, did you check for fuel delivery to the main pump as previously suggested? If the tank pump whines and a stream of fuel is coming out of the disconnected fuel line behind the main pump you are getting fuel to the main pump.

The reverse polarity problem is, as far as I know, a product of aftermarket sending units (this from Art B's tank pump notes). Even so, it is fairly easily corrected.

Third of all, if you or your guy are going to "screw around" with the fuel distributor, there is a procedure that should be followed. It may be difficult if the car is not running correctly. You need a digital volt-ohm meter. They are fairly inexpensive and come in handy for other diagnostic procedures. However, the inexpensive ones will not measure duty cycle. For this I use an old dwell meter/tachometer, as mentioned below.

The italicized text was written by someone other than me. Also, this is for cars with the Lambda-Sond system. What you are setting is the duty cycle (on/off) of the frequency valve. Cars without an oxygen sensor require some means of measuring the CO content of the exhaust. Anyway, it goes like this:

MVP Tech Tips [There used to be a page on a website with this info but it has long since disappeared].

Setting base idle specs. on cars with K-Jetronic fuel injection and CIS

Many driveability and running problems can be traced to improper base engine settings. Setting your base idle specifications is always the first step when trouble shooting any runability problem. By following the steps below the source of most problems can be identified.

1) Check for air leaks by spraying carburetor cleaner on all intake hoses and gaskets including the injector seals. Any fluctuation in idle while an area is being sprayed means a leak. Repair any leaks you find. Don't spray carburetor cleaner on hot manifolds as it may cause a fire.

2) Remove and clean the throttle body, then reinstall it using new gaskets. Make sure the throttle switch clicks as soon as you crack the throttle (adjust as needed).

3) Start your engine and let it warm up fully.

4) Set ignition timing to the manufacturer's specs.

5) Now use a voltmeter to verify that your 02 sensor is working properly. Connect the red probe from the voltmeter to the 02 sensor wire where it is connected to the large green wire. Connect the black probe from the voltmeter to ground. A good 02 sensor will fluctuate between .2 and .7 volts if your mixture is anywhere close. Replace the 02 sensor if needed.

TIME OUT. You can skip step 6 because your car does not, or at least should not, have the constant idle system. If your car has the auxilliary air valve then it does not have the constant idle system. I assume it does not have this feature.

OKAY. Back to the procedure.

6) Go to the left inner fender well and find the blue and white pigtail that sits besides the ignition ECU. This is your CIS test point. Ground this connector and adjust the throttle plate to 750 RPMs. Readjust the throttle micro switch as needed. Remove the ground from your test point, the idle should be close to 850 RPMs or 950 RPMs on turbos.

7) Next to the blue and white wire is a red pigtail. This is your CO test point. Using a DVOM that measures duty cycle connect the red probe to the red pigtail and connect the black probe to ground. The proper duty cycle is around 50%. Adjust the base CO through the small hole in the air flow meter using a long 3mm Allen wrench. Adjust it to 50% duty cycle. A dwell meter may also be used to set the CO. With a dwell meter adjust the CO to 45 degrees.

Congratulations! You have just set your engine's base idle specs.

Note: With CI fuel injection the lower the duty cycle or dwell, the richer the idle fuel mixture. Factory specification for base CO is a duty cycle of 54%-65% translated to a dwell reading of 49-59 degrees. In our experience we've found that a slightly richer idle CO provides the best idle and the best starting.

The above text does not explain how, exactly, to physically make this adjustment. There is a plug in the top of the fuel distributor which need to be removed. I'm guessing your guy has already done this. A small, I think maybe 3mm, hex key (Allen wrench) is inserted into the hole and into an adjustment screw in the arm that carries the air flow sensor plate. I forget which way is lean and which way is rich but it will become obvious upon adjustment while observing the meter.

A word about dwell meters. 90° on the dwell meter = 100% of the duty cycle. So 45° dwell = 50% duty cycle.

BUT SOME OF THEM DO NOT HAVE A 4 CYLINDER SCALE. That being the case, use the 8 cylinder scale and double the reading.

IF YOU ARE USING THE 8 CYLINDER SCALE ON AN 8 CYLINDER ENGINE, 90° on the dwell meter = 100% of the duty cycle. So 45° dwell = 50% duty cycle.

THEREFORE, IF YOU ARE USING THE 8 CYLINDER SCALE ON AN 4 CYLINDER ENGINE, 45° on the dwell meter = 100% of the duty cycle. So 22.5° dwell = 50% duty cycle.

If you want to shoot for the slightly richer setting (54%-65% ) suggested above you will be looking to set the dwell at 27°-32.5° I would go low on this for better fuel economy.

By now you probably want to sell the car. Fear not. It isn't as difficult as it sounds.

Easy for me to say, right?

BTW, if anyone sees any misinformation here don't hesitate to step in. That usually isn't a problem on this board anyway.


--
'80 DL 2 door, '89 DL Wagon