The extreme coincidence is the exact reason why I'm baffled , because it seems to go against all logic . However what your saying about the o2 sensor is the only thing that makes any sense considering its the only sensor that differentiates between sides of the engine . last question for the night , should my next step be to change o2 sensor and retry or do the relearn procedures and the o2 sensor and retry ?

 

If the plugs are fouled as bad as you say, the driver side O2 sensor is fouled just as bad. When the sensor is fouled, it will send data indicating a lean mixture causing the PCM to richen the fuel mixture, which will foul the plugs again. At this point, with the information you've provided, it's time to make an "educated guess" and replace the driver side oxygen sensor along with 6 new AC Delco 41-993 plugs with a gap of .060" Then, start the engine and hold it at 2000 RPM. If the misfires are not present, make sure the O2 sensors are both switching. If it's still missing, the relearn and cam retard adjustment are the next steps. Before the cam retard, inspect the drive gear for wear.

 

thanks for the advice i will reinstall the upper plenum ,along with new plugs and o2 sensor tomorrow , as well as look at the distributor gear tomorrow.

 

Some new info , after taking a break for a couple days I decided to tackle this again . First thing I did was took Captain Hooks advice and inspect the distributor for wear ,and noticed the gear definitely had visible wear and also noticed a slight amount of side to side movement ,I'm assuming it was the bushings being worn . After 200,000 miles im not surprised ,but I wasn't confident this was my fix cause it ran reasonably well before the rebuild . But either way it was worn and i did replace it. I got a cardone rebuilt unit . I did read some bad reviews about the plastic housings cracking where the screws for the cap go but they must be doing a better job cause the one i got had brass inserts installed for the screws.

Anyways , I put it all back together again and drove it to a reputable shop to have the crank relearn done and to set the cam retard .DAMN THIS THING RUNS LIKE GARBAGE. Unfortunately there wasnt much change if any . But for troubleshooting purposes I have to narrow these possible causes down to be able to figure this out . There is a silver lining though . The mechanic also used his computer to read the codes and do a little troubleshooting for me . What he found out was that it was only cylinder 5 causing the issues . He said it was a dead fire , not sure if that was a technical term or what but that was better than 1,3 and 5 i thought it was.

Tomorrows plan is to buy all new plugs again , put on a new delco cap and rotor , this time I will also pick up some new wires . From what I hear around this board is autolight wires are the way to go . I'm also planning on running a compression test . One other thing , the mechanic told me that it wasnt out of the realm of possibility that there might be something wrong with the valve springs on that cylinder , even though the cylinder heads have been rebuilt. Do you guys think that could be a possibility ? Is there a test that I could perform to rule that out ? Is a leakdown test something I could do at home ?
Really sorry for the long post sometimes i dont know when to shut up .

 

Get autolite professional wires. Be very careful on the routing of the #5 wire; it's touchy on getting it right and, if wrong, can cause a misfire (my #5 wire was cut by the metal piece the spark plug wire bracket sits on. Took me forever to find it.).

I'd get the ignitioon components right before I did a compression test. It's probably a wire/cap/rotor issue, but could be an injector or compression issue. One step at a time, however...

 

I agree, save your time on the compression & leakage tests, get all of the basics taken care of first. If there's a problem with a valve spring, a compression test and or cylinder leakage test probably will not detect it. Both tests pressurize the cylinder, which forces the valves to close. There are ways to check valve springs: Visually by checking for a broken spring, measuring "assembled valve height", and with test equipment that can measure spring tension.

Never heard the terminology "dead fire". If a cylinder is not producing any power, it's usually called a "dead miss".

 

No dice .. I replaced the cap and rotor again this time using delco ones, I replaced wires also with Autolight professional series . I replaced the plugs again , last time I had used delco platinum this time delco iridiums 41-993. I also replaced a couple dry rotted vacuum hoses I found. The night before I even removed the ignition module and heat sink and put dielectric grease between them as per " The Dreaded P0300 " post , I figured what the hell right somethings got to work.

When i first started it tonight after replacing the parts , the SES light was off , only for a minute though . It is running a little smoother but not enough to start driving it everyday again though . I did take it for a test drive and the light still starts flashing at like 28 mph and wont stop until speed drops below that point again. I really dont understand that part. Why is it speed initiated and not rpm based ? these vehicles dont have speed sensors for engine control , do they ?

Tonight while I was pulling the plugs anyways , I did decide to run a compression test. I did one before the teardown 5 weeks ago and it was all over the place , anywhere between 130 and 190 . So just for curiosity sake I did it again this time it was pretty much 180 across all cylinders with 2 and 5 being a little higher at 183ish. So at least I did something right there.

Maybe my next option should be to pull the valve covers off again to see if i can notice something in there . Any new ideas ? Maybe a vacuum test , will that tell me anything ?

 

Just a thought, but have you done a fuel pressure and leakdown test? If so, what were your results, KOEO and after 10 minutes?

 

Yeah first post of this topic ( I know its getting pretty wordy ) But anyway 64 psi pump on dropped to 60 pump off and only dropped to 57 by the end of 10 min.

 

There is a VSS, (vehicle speed sensor) and the PCM uses that data for several things: Cruise control, transmission shift points, 4WD transfer case shifting, ABS, (anti lock brakes) and engine controls. There are 2 other speed sensors used for ABS and all 3 sensors are monitored by the PCM for erratic behavior. If a sensor is not reporting correctly it will set a DTC in memory and turn on the SES light. If there are no DTC's in memory, the sensors are fine.

A flashing SES light indicates a misfire that can damage the catalytic converter. More than likely yours is flashing at 28mph due to the engine being under a load. Have an assistant put the trans in gear and hold a foot on the brake, then bring engine speed up to ~2000 RPM. This will apply a load to the engine. Then spray a mist of water over the ignition coil and watch for arching to ground. Look close, it may just be a small spark.