'89 Knocking (Rain and maybe EGR related)
I love my '89 ranger (or at least loved until recently). It's a 2.3L 4 cylinder 5-speed Manual.
My truck's been running for a long time, but in the last two years, it started knocking heavily after I went to a car wash, when I turned it on even from cold. I checked the codes and it said it was the EGR Valve Position sensor. I figured that couldn't be it since I didn't think it was active until the car got warm.
2) Replaced the EVP Sensor and it ran like a charm.
3) Similar problem happened 5-6 months later, same solution.
4) Similar problem happened 3-4 months later, same solution.
5) Rain-related problem happened 1-2 months later more heavy knocking, same solution.
6) Driving in the rain, it happened with heavy knocking and on my way home, my master cylinder acted up (basically just didn't boost brakes).
I checked my codes, as always, 34 - EVP Sensor Above Threshold came on.
I also noticed water was leaking in near my ECU. I still can't figure out where it's leaking from (But that's probably unrelated).
I got sick of it and replaced my whole EGR Valve and Sensor. The pipe from the exhaust to the EGR Valve had heavy corrosion, but was still fully in tact, so I kept it.
When I powered the truck back on, it behaved poorly. The EVP sensor and new EGR Valve didn't fix it. I checked the codes. But now, a plethora of codes came up.
21 - Engine Coolant Out of Range
22 - BP/MAP Sensor out of range <I don't even know what this is!
42 - HO2S Sensor System Rich Right Side
34 - EVP Sensor above threshold <It's a brand new sensor
I'm inclined to believe the rich bit since I was getting sick just sitting in the vehicle while the test was running.
For the heck of it, I did cylinder timing. It mentioned something was wrong and was corrected.
Still rough. Redid test.
Same codes, only now:
18 - SPOUT (Spark Plug Output Open Circuit)
13 - Low RPM Check
came up in addition to the others.
I'm starting to think there are two unrelated problems going on here.
1) Does anyone have any idea why my EVP Sensor would dramatically go out when I drive in heavy rain and cause knocking?
2) Why would replacing the EGR Valve assembly cause everything to go wrong.
3) The Haynes book suggested it might be vacuum related, does that sound right?
I'm totally clueless here. Can anyone provide any clues that may be able to help me?
Last edited by CNLohr; 10-06-2010 at 11:47 PM.