One of those days were nothing goes right.

[Sleeper1987]

Well my day started of with a loud ticking noise after i merged onto the freeway this moring and the car broke the intake rocker on the driver rear cylinder lots of knock retard at cruise. So i search all day and find a new rocker at of all places autozone (melling part).


ok so I get the car back together inspected all pushrods,rockershafts etc, pulled the spark plugs they looked pretty worn so i grabbed a new set of autolite 23's ( replacing r42ts ac delco's) at autohole gapped them at .030 thou (same gap as old plugs)


below is a picture of the plugs, the light color plugs has about 500 miles on it (broke plug changing manifold gaskets) and the rest are milage unknown.Look normal to you guys? no detonation shown on the plugs

(The Problem)
The car is surging under boost in hi gear (3rd) boost is set to 20psi (93 octane ) no Kr noted on scanmaster not even at shifts. The o2 mv drops to .058 in 3rd gear 7.97 in second 8.30 in first 5,200 rpm shift points.

Anyone have any ideas what has happened?

 

[Sleeper1987]

:frown: :frown:

 

[87geeinn]

20psi on pump gas? It sounds like knock to me. Check to see if your knock sensor is connected. It is located directly below the coil/ignition module on the back of the motor. What shape is your 02 sensor in?

 

[ES1]

I would be very concerned about your O2s in 3rd.

 

[Sleeper1987]

20psi on pump gas? It sounds like knock to me. Check to see if your knock sensor is connected. It is located directly below the coil/ignition module on the back of the motor. What shape is your 02 sensor in?

20 psi on 93 anymore it gets kr i run 110 octane on track nights and it usually has 3-4 gallons when i fill it up with 93 (9-10 gal)for the week

the knock sensor is connected and torqued to 14 ft lbs


O2 is recent cross counts are fine.


Just started this today after changing plugs and fixing the broken rocker.

 

[Sleeper1987]

I would be very concerned about your O2s in 3rd.

I am, thats why i made the thread up till today it has been around .760-.780 all the way to 5k in 3rd.

 

[norbs]

the plugs wont show much after you have idled. You have a serious fuel problem if the o2 drops to almost zero, probably filter, pump, low voltage, could be anything.

 

[ES1]

If your racing, you really need direct scan.
Also, a FP guage that you can read while under boost.

 

[Sleeper1987]

the plugs wont show much after you have idled. You have a serious fuel problem if the o2 drops to almost zero, probably filter, pump, low voltage, could be anything.

Yeah very true about the plugs.


fuel system

vortech t-rex pump hot wired 3/8 pickup in tank

new ac delco filter

pressure cleaned 009's

adjustable fpr set at 45psi line off. fuel pressure is 1:1 with boost

 

[Sleeper1987]

If your racing, you really need direct scan.
Also, a FP guage that you can read while under boost.

It has a autometer liquid filled fuel pressure gauge mounted on hood right in line of vision.

 

[Sleeper1987]

Maybe I pulled a vac line loose/wire or something.

 

[Sleeper1987]

Regapped to .025 and cleaned the corroded o2 sensor connector and all is back to normal.


3rd .787 2nd .799 1st .850 no more surging.


does anyone know if gm still carries the o2 plug from the harness side?

 

[Slo86GN]

Dunno if GM carries, but I got the one for my T from Casper's. It was showing some cracking/deterioration, so replaced it while the car is down.

 

[norbs]

its just a single pin weather pack connector, napa will have it. So it looks like it was a bad miss after all.

 

[Sleeper1987]

its just a single pin weather pack connector, napa will have it. So it looks like it was a bad miss after all.

will check out napa in the am.