I am pulling my hair out with this thing. I sprung a SMALL pinhole leak on the waterpump hose (the one with the bleed screw). I drove less than 2 miles like this. Never overheated or anything. The car stumbled and bogged down as I accelerated. If I go WOT, it runs like a champ. Doesn't matter what gear I am in. anywhere from idle to about 2500 it bogs down. If I come off the line hard, it is fine. No codes, no missing/backfiring. What do you think? This just happened today. Opti has 90 miles on it. How do you check these? Please help..................

 

I guess this is a GM Opti? The fact you don't have a DTC (service engine soon light) indicates the high and low-resolution pulses are still good. And that is good news! Therefore, it must be a small amount moisture in the cap causing arch-over between the posts.

Possibly you could place a constant vacuum (a pump) on the Opti vacuum side for a few hours to accelerate the internal drying. That would be much easier that removing it, however, antifreeze doesn’t evaporate quickly.

WD

 

when you remove the water pump to fix it it might be a good idea to replace the cap and rotor and clean the anti-freeze out of it

 

Update, after searching on here, I saw many O2 sensor problems, so I decided to disconnect mine. The problem seems to have gone away, runs great now with them disconnected (not throwing codes either ???). Only question I have is WHY?????? What did this do? How did this all of a sudden fix my problem. I want to post this for others in case they run into the same problem. Kinda weird but once again, you guys HELPED ME OUT!!

 

How hard was it to pull or disconnect the O2 sensor?

 

It was easy. Each O2 has it's own connector. Just be sure to tie-wrap them out of the way of the header and don't let it hang down to where it could catch something on the road and be pulled off.

 

Now by taking out the O2 sensor, will that affect your air/fuel ratio?

 

I am sure it will but I don't know how much. The car drives much better now ( I still need to dyno tune and replace O2s). I just want it drivable to keep breaking in the new motor.

Can anyone chime in on this one? What effects will there be by disconnecting the O2s?

 

HI,
SOUNDS LIKE A PROBLEM I HAD,PUT A NEW MSD DIST.WITH A VACUM,HOSE GOING TO MY INTAKE,WORG GOOD AFTER THAT.

GOOD LUCK, WAYNE
CANADA

 

First, if one or both of the O2s were bad you should get a DTC. Also, disconnecting the O2s should also cause a DTC.

Without the O2s connected the engine will not go into closed-loop.

I though your problem was a coolant leak on the Opti????? How did the O2s become the issue????

WD

 

Darn good question. Once before, I leaked on the opti and it killed it. Since the car ran fine, sprung a leak, ran like crap, I figured that I ruined the opti again. After reading some threads on here, I tried the O2s and BAM, cleared the problem (enough to say the O2s are bad). It didn't throw a code until I ran it outside of my neighborhood (over 1500 RPM), I will scan tonight and verify its throwing an O2 code.

I wasn't sure if it would stay in an open loop or not. This reassures me the opti is not bad, whew

In any case, this board ROCKS! You guys have been so helpful!!!

 

I've had this problem with O2s twice in the past year, once due to old age, and 2nd time likely due to a ton of flooded roads. If you have an ALDL cable get TTS datamaster, reconnect the O2s, then look at what datamaster is recording for the O2s. Chances are one of yours (left or right) will be above 1000. (usually it only goes to 800-950 @ wot). You don't have to wait for the car to warm up and enter closed loop to do this either, it will still read O2s in open loop; it just won't adjust any parameters in OL.

Then just replace the O2, problem will likely be solved.