DupermanDave

I got it. Test the wire connectors that plug into the TPS, write down those readings, and then text the connectors at the ECU and I should get the exact same readings?

DupermanDave

after resetting the CEL, I now only get code 71. It happen right as it started to idle really low and horribly. I dont have the gauges and tools to check vacuum levels as per the FSM. Is there anything else i can do to the EGR to test/fix it?

rechecked for leaks and made sure the hoses were going to the right places. Found nothing wrong.

4Crawler

iTrader: (3)

71 is the EGR temperature sensor. Make sure it is connected, if so, see if you can clean inside where the sensor is attached to the EGR. Or look into some of the threads talking about bypassing that sender.

abecedarian

71 should not ever come on at idle or right after starting. It's an EGR code and EGR only operates at part-throttle / cruising speeds after the ECU enters closed loop.

DupermanDave

It happened after driving a few miles home from work. I noticed it at a stop light after it started idling really low.

I already tried cleaning the sensor while I had the EGR out to replace the intake gasket. I guess I could try a deeper cleaning, but it was pretty clean already

4Crawler

iTrader: (3)

The way that sensor works is that first the ECU decides it is time to open the EGR valve. Assuming that happens then the hot exhaust gas flows through the valve and after a certain time, the ECU expects to see a temperature reading above some threshold on that sensor. This is what tells the ECU the EGR valve is working as expected. So either the valve is not opening under ECU control or the sensor is not reading a hot enough temp. fast enough to satisfy the ECU.

DupermanDave

Is it possible to replace just the sensor?

Also, which part should I take off and clean? The EGR behind the throttle body, or the part just below the EGR modulator? (AKA "this part" )

4Crawler

iTrader: (3)

Not sure if the sensor can be replaced, my '85 EGR is the sensor-less type. If not replaceable, then the whole EGR valve must be swapped out. I would first make sure that the EGR is opening (vacuum applied to the top of the valve should cause the engine to stumble and/or die at idle. Then make sure the EGR is getting turned on by the ECU when it should be. If all that is fine, then something is wrong with the sensor. Either replace it or the valve or bypass the sensor, I think some of the 49-state models have a bypass resistor that plugs into the temp sender connector to trick the ECU into thinking the temperature is OK.

DupermanDave

what tools would you use to check or create a vacuum (other than a vacuum cleaner)? Can they be rented from autozone?

Junkers88

I bought one of these a few years ago and have used it for all kinds of things.

http://www.amazon.com/Mityvac-MITMV8...684672-1824921

You might be able to rent something similar.

4Crawler

iTrader: (3)

You can pick up a hand vacuum pump w/ gauge for not a lot of money, very handy tool to have:

http://www.harborfreight.com/cpi/cta...emnumber=92474

Or just hook up a vacuum hose to the intake manifold and use that to actuate the EGR valve.

DupermanDave

I should also mention my EGR modulator filter keeps getting wet. I'd let it dry overnight and next time I drive it it gets moist.

It doesnt smell or feel like coolant. It's clear like water and smells like carbon/oil.