Car is 1991 Integra GS. 201k miles on the clock on original motor.

This is my daily driver. I recently changed the spark plugs for new NGK units. The old plugs were really worn and the gap had increased to quite a large size. The new plugs were gapped to .044"

Ever since changing to the new plugs my gas mileage has gone down significantly. From around 33mpg freeway down to 29 or so.

I'm also noticing the car slightly misses more now.

My strangest problem is whenever I engine brake for a long period, like coasting down a long hill, when I get to the bottom the car shudders and bogs for a few seconds when you first start to accelerate, and then it clears up again.

My first instinct is telling me a leaky fuel injector, but I was hoping you guys could offer some opinions on what would cause this sort of problem?


All of the old plugs were dirty and old, but looked to be burning in the proper A/F range.

thanks

 

check to make sure they are all still tight, and that none of your wires came apart or got damaged in the removal.

 

i'd gap them down to atleast 35 thousandths

 

keep in mind that this car is completely stock, I forgot to mention that.

They ran better with the old plugs, which were gapped at >.060, so I'm not sure how lowering it to .035 would help.

I've already ohm tested the wires, and the plugs are torqued down to 14ft/lbs.