What is going on with my 1999 buick century!?

You wouldn’t be able to check them with a volt meter. The voltage would be way too high. I just replace them with the new ones from rockauto.com that I mentioned.

Ill check the coils out tonight on rockauto.

I checked out that wiring harness I was suspecting…that didnt have any breaks in it.

I also checked RUNNING fuel pressure…it was also in spec and stayed constant…so fuel isnt an issue all the way up to the injectors. The engine runs entirely too rough to listen for the injectors clicking.

So suspects now are …several shit injectors… crank, cam or knock sensors…messed up computer…vacuum leak…idk… I have a deadline of sunday to get this thing acting right…its goin in the trash after that.

Bought it for $2000 in 07 and have driven it 100miles a day 5days aweek since then…it doesn’t owe me anything haha.

@d3r

Since you mentioned fuel injectors . . .

Are you set up to perform an injector balance test?

It would quickly confirm if you’ve got a leaking or stuck injector

Injector balance test? You may as well be speaking spanish to me haha…im by no means a mechanic. .I am just very capable of following direction. so im confident I can perform any diagnostic test. You can explain or ill have to google it.

I feel like im going to be an expert at the 3.1 by the time im through with this haha…ive had all the components off it several times now digging for answers.

Ill see if I can get a video of how rough it is running tomorrow to help you guys gauge what could be going on.

Ok heres a video… like I said before…the oil light will stay on the entire time its running. This video is with the MAF unplugged… it runs the same with the MAF connected- just shorter run time.

I think today im going to replace the cam and crank sensors and possibly the fuel pressure regulator.

I think it’s a simple mix up of the plug wires.

Get a printout from the auto parts store and follow it closely. I think you may have mixed up at least two.

Yosemite

Wouldnt that show up right away?

There was a bit of drama while changing them though. I ratchet strapped the engine forward so I could change all of them but only got the front 3 changed before my gf called n told me I needed to go pick our son up from school. So I never got to change the back 3…

started right up and sounded great…then died a few mins later…I changed the back 3 after it got towed home.

Ill double check though.

It appears to be a very regular miss, not a random miss. And yes it would have shown up right away. What’s more disturbing is what appears to be a lot of valve clatter. This is probably due to collapsed hydraulic valve lifters which is probably, in turn, caused by your low oil pressure. That would definitely cause a misfire. You need to address the low oil pressure before you do anything else.

Edit: Hate to ask the obvious but you have checked the oil level haven’t you?

Yes haha. the oil level is spot on. Regular oil changes and have never had an issue with losing or burning oil.
How do I go about trouble shooting oil pressure?

I’m afraid the only thing you can do is drop the oil pan and examine the oil pump. I’ve never heard of one failing in these engines but you may have a stuck pressure relief valve in the pump. Has any debris gotten into the pan lately?

One other thought. It’s extremely rare but an oil filter can collapse internally and the pieces can plug the filter. It’s quick, cheap and easy to just throw on another filter.

I’m just a novice but I would have said you have a misfire-coil, wires, plugs, wires not firmly attached to plugs. But the low oil pressure is extreme concern and I think I’m with @mytwocents
I would suspect though that you’d have a little lifter noise, but throw a different filter on and it would sure be nice to get a mechanical oil pressure gauge on it to see what the true pressure is.

Hmm I DID just get a free oil filter with one of my recent autozone purchases…ill change it out quick.

No debris shouldve gotten in recently. And when I drained the oil to change the timing chain the oil looked normal.

I figured the clatter was from the engine idling erratically.

Somewhat unrelated to what we were talking about (got too dark to mess with oil filter)
I did a “smoke test” for vacuum leaks… there was a small amount of smoke coming out over by the throttle. But I could HEAR air coming out from around the front pulleys. I think it may be coming from the timing chain cover…not normal right? I didnt see any smoke coming from it but could hear the hissing.

Do you have a check engine light on?

Service engine soon light when the key is on position…the only code is MAF low circuit. And the light goes out once its running.

With one or two dead cylinders, the oil light on and the noise you seem to have a mechanical problem. Something as simple as a broken rocker arm can allow the lifter to come out of its bore and a loss of oil pressure. I don’t know if that is possible on this engine but an example of a problem.

Determine witch cylinders are misfiring and perform a compression test.