My 1990 302 Econoline has new plugs, low mileage wires and cap, runs smoothly but lacks power on the highway and pings under acceleration.

Took it into the shop today and they put it on a scanner. Showed a code 34 for EGR. Also 3 wires were not fully connected to 3 sparks plugs on the left engine bank. Timing was off (retarded) 10 Degrees.

Have not replaced the EGR or EGR Position Sensor yet. I was told to change both although I do not know if the tech confirmed that the EGR was not getting vacum etc. Just the code.

With the spark wires re-attached and the timing set to spec it seems better, perhaps not perfect.

Should I replace the EGR and EGR Position Sensor? Unfortunately the person who will do it does not have a scanner so I cannot re-scan after I replace the EGR and sensor. I had the plugs replaced a few weeks ago and it was gutless before that, so the wire thing is not the main cause (although it didn't help).

Would faulty EGR and or position sensor cause loss of power and pinging under load and aceleration? As stated before otherwise runs smoothly,

Should I replace both items? Should I get the van scanned for codes after replacing the EGR and sensor? It will cost me extra to get scanned.

Another option (assuming the van runs better now with the timing and plugs connected, I haven't driven it enough to know how well it runs yet) would be to do nothing and wait until I need an Emmissions test in a month or so and then change the EGR and sensor if I fail the test.

Thoughts appreciated, don't want to change parts for nothing.

 

disconnect the vacuum to the EGR and see if you get a code 33 (= EVP sensor above/below specs) and check for vacuum at Idle. If you have alot ( will it stick to your finger?) the EVR is stuck open, and opening the EGR all the way, all the time. If you cannot feel the vacuum, rev the engine from the engine compartment and check for vacuum at a higher RPM. If you get vacuum when revved, the EVR is fine, check the EVP sensor. Get a ohmmeter and jumper two of the pins until you find the pair that reads about 3000 ohms. remove the EVP sensor, connect the ohmmeter to the pair you identified, now push the silver rod into the sensor. Bottomed out, it should read ~100 ohms. If this checks out, watch the ohmmeter as you push in and let out the silver rod on the sensor. it (ohms) should go down when you push in, smoothly, with no flat spots. If you find a flat spot, replace the EVP sensor, else replace the EGR valve.

Common sense tells us that if the EVP is working, has vacuum at the right time (rev up test), and the computer says that the EGR is not moving (code 34), the Problem is the EGR valve itself.

Do a search on "pulling codes". one of the results will have the method of pulling codes with a paperclip.

Good luck. This seems like alot, but is very easy to do.