Well, yet another development. Yesterday while on a longer than usual trip on the highway during 100 degree weather the fuel pump began to sing like an old blender on the Frappe setting. Tank about 1/2 full.

Nice thing about the cargo van is you can hear what's happening underneath a lot better than the conversion van with all it's carpeting and insulation.

I added a full can of Sea Foam to the fuel several days ago. Anyone experience fuel pump noise after adding Sea Foam or should I begin planning to replace my fuel pump?

Maybe my 1-3-5 misfire has something to do with the fuel pump or fuel pressure.

 

Oh, of course, sure, why didn't I think of that?! You hang on to that dream pal!

 

Cynical, arent we? Well, at least it's good to see the White Whale isn't winning the fight!

 

Don't count on that, lol, it does still have the misfire on the left bank.

 

You ever try replacing the 2 wire coolant temp sensor on the intake manifold?

 

Yessiree!

 

Finally got around to checking spark plugs today. Previous owner told me the plugs were replaced a few thousand miles before I bought the van. Sure enough, they're in great shape - almost new.

They are Champion 7436 platinums. Four gapped at .045 and two gapped at .050. Not good. No matter, I HATE Champion plugs - I think they all SUCK; copper, platinum, whatever.

I installed six Denso Platinum TT 4503 plugs which I gapped properly at .040. The engine is definitely running better with the Densos.

Reset the MIL. Again.

 

MIL back on, no surprises here-- same codes for 1-3-5 misfire.

After changing Champion plugs out for Denso plugs I've increased combined city/highway fuel economy 3 MPG from 15 to 18. New air filter is probably lending a hand.

 

Might want to run a compression test and see if that gives any indication.

 

Yes, time probably to check the compression. I should have done that when I did the plugs but I didn't have access to a compression test gauge on that day.

I still believe my problem to be temperature related and I have not changed the 2-wire coolant temp sensor or the air temp sensor, both located in the intake manifold.

Air temp sensor is very easy to change but if memory serves the 2-wire coolant temp sensor is buried up front near the thermostat housing.

Unless Mopar changed it in 1998 for some reason.