A couple days ago I decided to replace the oil pressure sensor b/c the gauge was pegged, and when i fooled with the sensing unit it would work a little and then drop to below 0. Anyway, do to a couple of mix ups from the parts store it was a few days till i got the unit. I hadn't driven it since like saturday (went quite a distance on sat. with no problems) altho I did start it a few times since then, altho i take it out of the driveway. So I replace the sensor today (had to go get a tap and die set to repair threads on the port for the sending unit. This is turning into such a nightmare!) And now it cranks fine but as soon as it starts the engine revs to like 3500-4000 rpms, then dies. It'll stay on longer if i give it a little gas, but then the RPMs skyrocket all of a sudden (no apparent correlation to throttle position) and then it starts to chug and sounds like it might be backfiring out the intake altho I can't tell due to the dual snorkle and all (can't see anything coming out), but that's what it sounds like. I pulled one of my spark plugs and it's like a charcoal black and there appears to be oil around the threads. Did I blow piston rings or something? My car was running fine until i changed the oil pressure sending unit, now all of a sudden it seems to be having a nuclear meltdown. It's an 88 camaro 2.8mpfi w/ 97k on it. I've tried everything i can think of (reset ECM, checked for trouble codes, checked for fuel pump, checked the amount of oil) and haven't found any reason for this. Thanks for all your help, sorry this took so long, Joe

 

my trans am did that when i first got it and i still had some hope for the 350. turned out to be a HUGE vacuum leak at the back of the manifold. look for all the small stuff like that before you jump to any big conclusions

 

Sounds like your describing intake back firing.

I would say check timing.
And CHECK Vacuum lines for leaks.

After that I do now know. But I would say that your problem lives in one of those two.

 

BINGO!
Hose at base of distributor, driver side.
You broke the rubber hose.
Get 1/2 heater hose, length about 3-4", lots of motor oil, lube end slipping onto motor fitting, attach the PVC plastic pipe and you're probably good to go.
If ya didn't touch the timing, no reason why to check now.

How did you change your fitting?
From above or from below?

 

I changed it from the top, i used a set of channel locks to loosen it and then after i screwed it back in I used them again to get it good and tight. I've checked all the vacuum hoses I could find, no leaks or breaks. I'll check for that hose by the distributor in the morning. As for the timing, I just set it like a week and a half ago at 12* ATDC and hadn't been having any problems. What I don't understand is how this happened, since all I did was change the sending unit. I dunno, I'm just hoping to get it running again, I'm not ready for a new engine just yet. Thanks for all your help guys!

 

If it ran fine before it'll be fine again.
You caused something to happen.
Start searching.
I have to add the oil pressure sending unit to my 1985 so I can switch dashes to gauges.
I'm waiting to do it when I change the oil soon.
Might as well!

 

SHE LIVES AGAIN! It turned out to indeed be a vacuum leak, it was that HUGE hose from the manifold to what looks like either power steering or the brake master cylinder. That hose was so big, I didn't even realize it was a vacuum line. Thanks so much for all your help. Joe

 

Right on good to hear the problem is solved.