1995 4wd 4dr LS blazer, OBD II equiped, but it doesn't pick up this problem.

My engine Idle's erratically, like its missing, i also failed emissions (but that was before i replaced the EGR valve).

and also, when i stop or put it in park, or turn my wheel while in park the oil pressure drops to about 35 then back up to 50 where it usually is. i just changed the oil last week. When the oil pressure goes crazy my engine usually drops in RPM too, from 700(normal idle) to about 550. This drop only lasts a second or too.

Any Ideas? im going to pick-a-part to see if i cant scavenge some parts for my blazer (im going to try and grab a FPR, distributer, caps and rotor.. and anything else cool i can find )

p.s. theres a slight gas smell around my car, but no signs of a leak

 

I wouldn't waste your time with a used FPR.

The drop in RPM (and associated oil pressure drop) are normal when you are loading up the engine. Basically when you turn the steering wheel when stopped, the power steering pump is pulling power from the motor to turn the wheels. Sounds normal.

On the miss at idle, when was the last time that a tune up was done? Also, when was the last time that you tried any fuel system cleaners?

Just a point of clarification. In '95, the OBD system used was a mix of OBD1 and OBD2 commonly referred to as OBD1.5. It isn't, in the strictest sense, OBD1 nor is it OBD2. The emissions requirements of OBD2 were added to the OBD1 engine controls (ie the addition of the pre-cat & post-cat O2 sensors). There are other changes, but that is just one example of the mess that is OBD1.5.

 

Couple fo things can cause an engine to idle goofy.
TPS, a/c compressor kicking on and off due to low freon level, or the IAC.

 

just replaced the sparkplugs, fuel filter, oil filter, engine oil not long ago, i guess ill just go to advanced and see if i cant grab a rotor, distributor, and wires
just used fuel cleaner 3 fill ups ago

 

i bought new sparkplug wires today but they wont get in for a few days, i checked my exhaust and the missing is very regular, like a "put.put.put.blagh.put.put.put" etc

still cant figure out where the gas smell is comming from