Do you have a scan tool that will display live data? I predict you are going to need one before you are done. Pretty difficult to work on a Blazer misfire code without one. If you have nothing currently, I personally recommend Car Gauge Pro for Android and the BAFX Blue tooth OBD2 adapter from Amazon. About $35 for both. The Car Gauge Pro will allow you to display and set the camshaft retard (CMP Retard) which is one of the suspect things on your vehicle (effectively checks precise distributor rotor position). I know of no other inexpensive scan tools that will do this. One thing about this software is the PID and module list is not filtered at all by year and vehicle, so if you buy it don't be surprised or peeved when you run across things listed that it will not do. Just accept it for what it can do on our Blazers, which is a LOT. Your option is to spend considerably more money.

 

OK, checked the plenum with carb cleaner and no change.
I cleared the codes and when it re-popped the following is the freeze data:
Trouble code---P0300,
Engine RPM ----2166,
Calc load (%) --- 10.2,
MAF (LB/M)-----2.40,
MAP ("HG) ------8.3,
Coolant (F) ----- 165,
LT FTRM1(%)----5.5
ST FTRM1(%)----0.0
LT FTRM2(%)----2.3
ST FTRM2(%)----0.0
VEH SPEED (MPH) --- 0
FUEL SYS1----CLSD
FUEL SYS2----CLSD

 

Lesmyer I'm using an Actron SuperScanner (CP9145)

 

Could someone explain Fun-v's values to me? I'm having the same problems, same code but, no ses. Well the only time it's come on was yesterday morning,went off on the way home. I want to compare his scan to what I have on my actron cp9185. Thanks guys. This is almost fun...

 

Anybody have other ideas? coil seems to be fine, bench tested and "mist" tested fine.
could it have anything to do with the long term fuel trim bank 1 and 2 being in the positive number range? Grasping at straws here. If no other ideas might have to start throwing more money at it & get another set of rotor/cap but AC Delco this time, and replace the E3 plugs.

 

In post #12, your coolant temp indicates 165F. If that's the normal operating temp, it's a problem. It will affect fuel mileage and fuel trims. It needs to be 200F + or - 2 or 3 degrees, depending on ambient temperature.


Positive fuel trims indicate a lean condition, (not enough fuel, or too much air) and the PCM is adding fuel. Could be a vacuum leak, (air intrusive) clogged fuel injector nozzle, low fuel pressure and or volume.

Negative fuel trims indicate a rich condition, (too much fuel or not enough air) and the PCM is subtracting fuel. Could be a clogged air filter, misfires due to secondary ignition problems, (including incorrect CMP retard), a fuel leak in the plenum, (leaky fuel injector nozzle, leaky fuel pressure regulator, etc).


In both cases, there are other possible causes, these are the most common.

 

**UPDATE**
OK, so I saw in another thread someone had the same issue for several months and tried something simple, he put dielectric grease between the ICM and the heat radiator fin thing (please excuse my lack of technical terms here) and the P0300 went away. So this morning driving by the parts store I stopped in and get some dielectric grease and put it on the back of the ICM, and for ****s and giggles put it on all the distributor cap connections and guess what? The code disappeared and hasn't come back, even after running for about 45 min, even "simulated" a smog check and ran it at 2000-2500 RPM for 180 seconds, nothing.

One question though, the idle RPM is sitting right about 600 RPM; that seems pretty low, and since the idle RPM is controlled by the "brain", is 600 RPM right or is there a way to adjust it to around 800 RPM

 

Yep, 600ish is the proper engine idle speed.

Nice work so far!

 

Silicone dielectric grease should be applied to all terminals of the distributor cap, inside and out, when the cap is replaced.

The ignition control module requires heat sink compound, not silicone dielectric grease.

 

well, got the moving permit, went to smog it and the SES light popped.
it's now running rough and freeze data is as follows:
Code P0300
RPM -- 2795
calc load(%) -- 43.0
MAF (LB/m) -- 9.82
MAO ("HG) -- 24.5
Coolant -- 199
LT FTRM1 -- 25.0
ST FTRM1 -- 50.0
LT FTRM2 -- 25.0
ST FTRM2 -- 50.0
Veh speed -- 36
Fuel Sys1 -- clsd
fuel sys2 -- clsd

I need help