As the subject states, my car is throwing a 32, 42, and 43. It is a stock '91 305 tpi. I'll start with 32. The engine was rebuilt and i have a feeling the egr valve wasn't hooked up correctly. I have the bottom port on the erg solenoid going to the vaccume at the TB, and the top port hooked up to the vaccume connection on the top of the EGR valve. On the bottom of the valve, there is another vaccume hose that comes out and hooks up to something that looks like a vaccume pump, its small and not mounted to anything, just sort of floating there. Comming out of that is a T connector with 2 vaccume ports. And nothing is hooked up to those. I'm pretty sure thats where the problem is, since the egr solenoid is new, and when I pull vaccume on the hose connected to the egr valve, the valve moves.

Code 43 is because i have the est bypass disconnected, this is necessary for the engine to run with a decent amount of power, otherwise, it bogs down and stalls due to the code 42, i believe.

The code 42 is the one i've had the most trouble with. So far, i've replaced the knock sensor, which is the correct resistance for the speed density setup, the knock sensor connector and the ecm and memcal. I'm not sure what else it can be.

If anyone has some experience with either of these codes, i'd appreciate the help, for the 3 years i've owned the car, the check engine light has never gone off. I'd like to change that this summer.

 

There are two methods:

1. Remove the lamp;

2. Repair the problems.


I'm guessing you're leaning toward the latter.

First, the EGR solenoid. There are three ports on the typical stock EGR solenoid. One is connected to intake vacuum, one is connected to the EGR valve pilot diaphragm, and the other is vented to atmosphere (and originally had a foam cube glued to it to act as a filter). Little doubt that your "filter" is long since deteriorated and is gone. It isn't a critical item. What is important is that the hoses are connected properly and that the atmospheric vent is open. When the EGR solenoid shuts off vacuum to the valve pilot, the vacuum is vented through this port to immediately dump the EGR valve to the closed position. This one still has the filter attached:



If the solenoid is installed in the original configuration and position, the rear facing port should have no line connected, and once had a foam filter attached. The upper/forward facing port should have the line connected to the EGR valve itself (the black line in the photo). The lower/forward facing port should have the vacuum sounce from the throttle body connected (the gray line in the photo):



The valve you describe with the "vacuum pump" and "tee" is a mystery. Have a photo? If you have a handheld vacuum pump (or clean piece of vacuum hose and mouth suction) you should be able to determine which port serves which function. Please, no "suction" comments.

As for the '42', disconnecting the EST bypass will set that error code. If you reconnect the bypass, clear the codes, and try it again, what are the results? If the '42' persists, you may have a problem with the HEI switching module in the distributor base, distributor connections, EST module connections, or detonation sensor and/or its connection.

 

Here is the picture you requested of the vaccume-pump looking thing. It is attached to the egr valve(not pictured) by a vaccume hose. The map sensor label is for reference.

As for the code 42 and 43, i'm pretty sure the 42 disappears when the est bypass is connected, but the code 43 persists. I will confirm this tomorrow. Is there any other test you can recommend aside from the voltmeter test on the knock sensor harness which would give me a better idea of what component is malfunctioning. Keep in mind that the computer and knock sensor are both new.

Another symptom the car is experiencing is a sinusoidal idle of about +/- 100 rpm around the 600rpm mark. I'm pretty sure this has to do with the codes i'm throwing. I don't hear any hiss in the engine bay which would sugest a vaccume leak.

Sorry for the size of the image, this my first attempt at attaching a picture.

 

Just an update, I disconnected the thing that resembled a vaccume pump, and it is not a vaccume pump. Hot, what i assume to be exhaust gas, came out of the port which it was connected to. So I have no idea what it could be, a heat dissipator perhaps, but then there are still the two ports comming out of the end of it. But, i hooked all the lines up, and reconnected the est, and my code 32 and 42 disappear, all that is left is code 43, for which I am at a loss. I'll take the car for a ride to check for drivability/power compared to how it was before.

 

One more update:

I road tested the car with just the code 43 and it was not drivable. The throttle was very unresponsive, and the exhaust had a completely different sound. I disconnected the est bypass wire, and it became more drivable, but still a slightly unresponsive throttle and underpowered feeling, then I disconnected the egr valve, restoring the car to the state it was in before i began fiddling. And the car was responsive, and fast, like it should be, but with all the codes that were there before. So i guess my problem now is how to get rid of a code 43. Any suggestions?