I have a 96 E350 5.8 van that is driving me crazy with an intermittent problem in the EGR system. Does not seem to matter if the engine is cold or warm. Sometimes when I start the engine (50% of the time) the EGR valve opens immediately, and because the EGR is not supposed to be open when starting or idling, the van coughs and sputters, and sometimes even stalls. I installed a vac gauge into the line to the EGR valve and mounted it so I can see the vacuum when I'm driving. I am pretty sure the valve is not sticking open because if that were the case my idle would be terrible all the time. Aside from this intermittent issue where the valve opens when I start the engine the EGR appears to operate properly the rest of the time.
Any ideas about what might be causing this?

Thanks for any suggestions

 

You can confirm an EGR problem by just removing the vacuum line from the valve and plugging it to see if the problem is completely gone. Are you getting a check engine light? If possible have the computer checked for any codes. There is an EGR position sensor that is supposed to report to the ECM when the EGR valve is working and if it is working when not supposed to, the ECM should throw a code.

 

It is definitely the vacuum being applied to the EGR valve when I start the engine. I swapped out the vacuum gauge with my vacuum pump that has a vac release on it, and I ran the tube all the way into the van so that when this happens I just press the vac release button for as long as it takes to relieve the vacuum till whatever it is closes off the vacuum to the EGR. Using this method I have been able to prevent the engine from stalling.
Previously I was getting both 326 and 327 codes (EGR high/low). Replacing the EGR and it's sensor did nothing, so I replaced the PCM. Codes are now gone, and no Engine Light, but the starting problem remains. Actually I wish it would throw a code so at least I would have something to go on. I am guessing the next step would be to replace the EGR solenoid(s) valve(s) because one of them might be sticking? Whatever it is that is doing this seems to correct itself after a short time, sometimes a second or two and sometimes up to 20 seconds. The big question is whether a solenoid valve is sticking or is the PCM telling the valve to open because of a false reading it might be receiving from an entirely different component? I'm not sure what to try next since I don't know the logic of how the entire EGR system operates in relation to other engine parameters.
To answer your question directly, Yes, the problem does not happen if the EGR vac line is disconnected completely.