87 tbi 350 popping at idle and running rich

[devildogcummins]

Tested fuel pressure last week, key on 11psi before fuel filter and 11 at idle. changed egr valve and the popping has stopped at idle, if i give it a small rev it will pop out left exhaust still for 10-15 seconds, then idles smooth. still no codes. Have looked everywhere for a egr solenoid, but cant find one anywhere, mine is a 3 wire plug with a filter.

 

[gmbellew]

were the EGR passages clear in the intake manifold? are you sure the EGR valve is the correct type? there are positive answers negative backpressure valves. they look very similar, but they are not interchangeable.

you can test the EGR solenoid with a mityvac easy enough

 

[gpw0911]

My truck was doing the exact same thing except it was the passenger side doing it. It would idle fine and then every 10 seconds or so I would get a back fire out of one tail pipe. Check engine light was not on. I had just put on full exhaust and headers and then it started doing it. Come to find out the previous owner had the longer of the two spark plug wires going to #4 instead of #2, and when I put the wires back on after putting on the headers, I put the longer wire to #2 and started getting the backfiring. I suspected it was a spark plug wire causing it so I pulled them all off and re-did it, and that fixed my problem. Since you just did your spark plug wires, I bet you got a wire crossed.