ok...89 E350 with the 351. The smog pump was going bad, the bearings were beginning to whine and i thought the thing would lock up any second. So i removed it, long with all the plumbing, from the pump to the aluminum tubes that connect to the exhaust manifold. The crossover pipe that is plumbed into the smog system that connects the two heads i capped, because i did not think it would be easy to plug whatever holes were there. The only connections to the vacume system i found were 2 vacume lines that connected to what i assume is the valving system where the line from the smog pump is seperated into the plumbing that goes to the heads and manifolds. And one vacume line that controlls a switch pumping air into the air filter housing. I plugged these three lines and plugged all holes. I think i removed pretty much all the smog system. There is no cat on the van either. My question is this. The performance is bad. I began with a stock van, cut the exaust and put in a flow master, performance was awsome, but the noise was too much in the van, so the exhaust shop put in a glasspack to help quiet it down, but the performance dropped. On a few long trips the van would suddenly randomly surge with power, ususlly up hills. Now that i have removed the smog equipment the surge is gone and i have low power. Any suggestions, i am going to try a new o2 sensor, but is there one that would work better in the van with no cat or smog stuff? Any other suggestions about the random surge of power? Also, in every ford i have ever driven the valves tap under power and its verry annoying. I call it the ford noise, unless i run premium fuel in a one ton van that ges like 6 MPG the valves tap relentlessly. Any way to stop this.
Sorry for being long winded, just want to give you all the info.

 

that knock is caused by carbon buildup the best thing ive found is to run a tank of premium every month to burn that crap out.

 

[updated:LAST EDITED ON 05-Dec-02 AT 09:08 AM (EST)]just a quick question.. is it fuel injected? If it is... I would check the MAP sensor. If you have a vacuum advance distributor, I would check to make sure the diaphram isn't leaking... on the same note, check to see if the mechanical advance is working too. A replacement distributor can usually be had for anywhere between 40-85 bucks from an auto parts store. Oh, and not using a cat can affect the readings from an O2 sensor... you might ask others what they have done in the same situation.

 

Hmmm. I don't think that the lack of a cat would throw off the readings from the O2 sensor. I'm pretty sure that on the 89's the O2 sensor was in front of both cats. I've read that the MAP sensor is a critical part in telling the computer what kind of advance to give to the ignition timing (there shouldn't be vacuum or centrifugal advance on a EFI computer controlled setup). If the MAP sensor is giving a faulty reading, the computer will not advance the timing enough or too much (causing pinging, I think this was the noise you said sounded like lifters). Check the MAP sensor and check the initial timing (be sure to unplug the SPOUT connector when setting the timing). Hope this helps out.