Hello all, I'm looking for a little help on an EGR issue I'm having. I have an 89 F150 with a 5.8 , C6 , 4x4. I keep getting a code 34(low voltage to EGR) I have reset the computer by removing the battery and running again. I'm getting the code with the Key On Engine Off. The engine light comes on only after driving for 10 mins or warmed up ect..The light goes out after a restart and then come on again after a while. Again this points out a a closed loop EGR problem.

I have removed the EGR sensor and the little needle moves freely. I've sprayed and burnished the contacts to the sensor. I have also hooked up a small hand pump to the EGR valve and It does move but I can only get about 5"Hg.

Where do I go from here? I cannot find a step by step trouble shooting guide to know what is the issue. Most of the info is directed to a dead link. If someone can fill me in on some of the info I would be grateful. What resistance should the sensor have and to which contact? How does the EGR valve itself work? What should the vacuum be at the EGR at idle? Maybe there's a leak in the Vacuum system?

The engine overall runs well. I have done a tune up but not wires. My last comment is when warmed up the idle "feels" weak and maybe missing when in gear.

thanks for any help.

bob

 

check your can and the hose going to it...

 

The coffee can on the passengers side? I'll look it over at lunch time. I believe everything is hooked up but I'll verify. May I ask what what it does?

OK it's the Vacuum res. I'll still check it .

 

They get clogged or the hose may be cracked and leaking

 

I'm reading 18"Hg at the black hose input at the coffee can. and 20" at the manifold.