Hey, need a little help again. 87 F150 5.0. It's been running progressively rougher and rougher. It feels like a strong miss, bucks the truck pretty good. Scanner showed codes 84 and 67. 84 is egr vent fault. 67 is something about a neutral switch. I'm more worried about the egr. Is this more of a solenoid issue? Or should I be hunting down a vacuum leak? I'll be sure to clean the egr valve too. Thanks!

 

I think 84 refers to the EGR vacuum regulator not working, so possibly solenoid related.

67 Shows park/neutral safety switch failure.

 

I pulled the vacuum line off the top of three egr valve, but it didn't have vacuum, even when revving the engine. how do I diagnose this? I have a multimeter but am new to using it. thanks

 

First check to see if the line is still intact to the solenoid, if it is test to see if the solenoid is getting power when it should be. Check the resistance of the solenoid, should be between 30 -70 ohms

Then with key on engine off test for power, test between ground and the lead on the solenoid, should be above 10.5 volts.

 

bringing This back... The evr is basically crumbling apart, both at the connector and where the vacuum lines attach. Going to junkyard tomorrow and will try to buy evr with vacuum lines intact.

 

It's a hard call. If you're having problems with the EGR system it's almost better to go through the troubleshooting routine outlined in one of the repair manuals.

Check:

1: Vacuum system incl. vacuum reserve canister

2: EVR solonoid & connector

3: EGR valve

4: EGR valve position sensor & connector

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The entire EGR system cycles at a rate of something like a rate of 20 - 30 times a second. That's pretty fast when you think about it. It just seems like everything in the system would have to be in tip top shape in order for it to work right.

Chances are that an EVR out of the junkyard isn't going to be in the best of shape. Might work ... might not. You could end up chasing your tail.

A new one is something like 40.00 bucks ? It might save a lot of time and running around to hit it right on the first shot. That way you know the job is done and you can move on to the next thing.

 

You're right. I went ahead and bought a new one for $26. Code 84 went away, but now I have code 33. I still don't feel like it's getting any suction at the vacuum line that goes to the EGR, even at 2500 RPMs. The vacuum line (green) seems to be ok, and I don't hear any hissing. The line coming from the coffee can to the EVR seems to have vacuum. I'm stumped.

 

I think you're on the right track if the code 84 went away.

Don't let that lack of vacuum at the EGR throw you off. There are only very specific times that the computer tells the EGR to open.

This explains the times when it's called into action.

http://oldfuelinjection.com/?p=64

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It's hard to do diagnostics without the repair manual,an ohm meter, and a vacuum pump/guage.

Been having troubles with my EVR / EGR system too. I wandered around for quite awhile trying to piece all of the information together from this source and that. It wasn't until the Haynes that i had ordered came in that i was able to make sense of things and pin down the problem.

There is a specific procedure for testing the EVR but it's too detailed to go into here.

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I was just looking through the repair manual. Where yours is an 87 is it possibly one of the older systems that uses two EVR solonoid valves instead of just one ?

The vacuum diagram under the hood might give you a hint if it's still there.