Guys , bought this 96 Blazer 2 door that was not running. Replaced timing gear & chain, cap & rotor,wires & plugs . Got it running & had a p0300 code.Bought 4 new 02 sensors & lost the P0300, but now have a P0306 code. Also put on a new distributor gear.
Scanned it with Actron CP 9185 idleing ,looked at the ign advance & needed some advice abou it . Here are the first 20 frames ,frame 0 mil off ,frame 1 mil on & set P0306 code .

frame 0 ign advance -17.5 frame 1 ign adv -20.0
2 -19.0 3 -20.5
4 -17.5 5 -21.0
6 -17.0 7 -19.5
8 -21.0 9 -18.5
10 -18 11 -18.5
12 -19.0 13 -18.5
14 -20.0 15 -21.0
16 -22.5 17 -19.5
18 -23.0 19 -22.5

Dont know if these readings are OK or jumping around too much. Are there other readings that would help find the reason for the P0306 code .

Thanks ,
Sherman

 

im going thru the same crap with my 95, but i have no codes, mine too jumps around like yours, and in the negative. i think ive found why its negative though on the scanner, i checked my crank marks with the timing gun and its advanced the same amount the pcm retards the timing. and the idle timing is supposed to be zero. so i think the pcm is compensating the ignition timing from mechanical timing.


in your case id do a comp check and a fuel pressure check.

 

Have you checked/adjusted camshaft retard? On 1996 and newer CSFI systems, any time the distributor is removed, camshaft retard should be checked and adjusted if necessary. With the engine at 2,000 RPM, the desired spec is zero degrees, with a tolerance of 2 degrees plus or minus. It is adjusted by turning the distributor. It can not be checked with a timing light. Gotta use a capable scan tool, Tech2, Solus, Modis, etc. The el cheapo $300 or $400 jobbies that the auto parts stores use won't access it.

 

There is no adjustment on the EDI distributors used on the 96+ (and some 95's)... At least none of the ones I have ever worked on. The only way to gain an adjustment is to either slot the hole in the hold down clamp or to round out the area of the distributor body that the clamp mounts into.

 

Kyle,
Did you ever do a rebuild on a EDI dist. ? How much clearance should one have when you pull up on the dist. shaft ? If it has too much ,why would it only give a P0306 ?
I can clear the P0306 code & just sitting there idleing , it will come back (P0306 ). I thought it would make more sense if it gave a P0300 .

Thanks,
Sherman

 

I have never rebuilt one, but when this question came up a long while ago, the research I did into resulted in around 0.010" to 0.020" worth of clearance or play in the distributor shaft.

I would not think that high clearance in the distributor shaft would cause a P0306 code. Logically, one would think that if play were affecting the timing, it would affect all of the cylinders equally, not just one. Which is what you thought as well.

Have you tested the compression on cylinder #6? How about the plug & wire? Does the terminal inside the cap for #6 look any different than the rest (you'll have to follow the trace from the tower outside to the appropriate terminal inside)?

 

Kyle ,
I just went out to my garage & pulled the plug on #6 , had some black soot around the edge , but electrode was clean, changed wire , cleared code .
Started it up & still threw P0306 code, did a little old school testing , pulled the plug wire off #6 , could see it had plenty good spark & it didn't make any difference if plugwire was on or off still ran the same . So that tells me no fuel , what do you think
bad or stuck injector ? Blazer had been sitting since 08. Maybe run Seafoam in the tank with gas ?
Thanks again,
Sherman

 

You've narrowed it down to either a fuel or compression problem.

Has the main connector been removed recently from the injection spider on top of the engine? If so, remove it again to check and see if there are any bent pins. This is one of those things that is often overlooked, but can be easy to have happen to you. Especially if the connector is pried up at an angle when removed as this will bend the pins even before you try to put the connector back on.

 

Thanks Kyle,
I will check that tomorrow, just went down to Chevy dealership to see a buddy & get his price on spider #12568332 (new # is 19210688) , he can get it for $209 . Checked gm parts direct & their price is now $179 + shipping . Heard some where some one was charged $38 for shipping. I'll probably just get it here if I don't find any bent pins or the seafoam doesn't help.
Will let you know if I find anything,
Thanks for ever ones help,

Sherman

 

When the hold down bolt is loosened, there's enough movement of the distributor housing to correct for approximately 15 total degrees. If you need to correct for more than that, there are other problems... either worn bushings, the driven gear is worn, or the gear is off a tooth or more, but in that case, P1345 is usually set. This is how camshaft retard is adjusted, no modifications are necessary.