Well my check engine light came on, and off about 30 seconds later. So I went to autozone and pulled the codes and got 32 and 33. Both said EGR valve.

So my girlfriend's dad and I start to look at it. We open up the haynes manual and test the sensors and crap. When I check the the EVP sensor for ref voltage w/ the key on instead of getting 5.0 volts I got 3.86 or some ****. When we applied 10 in of vacuum instead of getting 100 ohms we got 800. We checked the amount of vacuum at idle and got NONE. So we ran the vacuum gauge into my the truck and drove around. I got about 3 in of vacuum at most under load and accellerating. As soon as I opened the throttle up or starting braking/deaccelerating I lost all vacuum.

We then took the EGR valve completely off and check the diaphragm(sp?) and stuff and it worked fine as we could tell.

The light came on last weekend, and since then i've been getting erratic idles. Like when first turning on, instead of staying around 1400 then dropping down to 800 or so after 30 seconds it'll go from 1000 - 1500 for like five minutes and just jump around. And my gas mileage has gone down atleast 2 mpg. And when you only get 10 - 11 already it hurts.

Now, we really can't figure out what is at fault. We're getting stuff, but I don't know what is normal and what isn't.

Any ideas?

Oh yeah, my rig is in my sig.

 

Your EVP was outside of the specified tolerance, so that would be a good place to start.

As for your vacuum readings: These may be normal. The vacuum to the EGR is controlled/regulated by a solenoid valve. Your ECM tells the solenoid valve to open/close under certain operating conditions. So, you should NOT expect to see vacuum at the EGR all of the time. But, 3" sounds low. Maybe your solenoid valve is sticking or leaking. If the EVP replacement does not correct the problem, I would try the solenoid next. I think they run ~$45 from Ford and they are prone to failure.

 

I have a 90 w/302. I pulled codes and it said 33 and 44. (EGR & Thermactor sys) I was reading the post, and replies.

My question is, where is the EGR solenoid valve located? Is this w/in the EGR valve or in a different location?

Please help!