So splice pack 423 is just a bunch of wires that get ground with a bolt through them. now i got it, thanks. but i dont think my 1995 truck has it? the only thing i remember when i was searching for a bad turn signal wire was a few grounds at the very back of the truck frame rail on the drivers side. at the time i took off the bolt and cleaned the area and put it back. so would that be my splice pack for the EGR and all the other sensors?

 

Hello, could this splice pack 423 be the cause of a random po300 miss fire? The CEL flashes.... did everything, but change the distributor stem. I do not feel the miss, but cat was clog when i got the blazer and secondary air pump was blown and intake manifold valve stuck open ('01).

 

yes, absolutely yes, because when i had my scanner hooked up when i had my sputtering, bucking problem i would watch the misfire counters and every cylinder would misfire during the bucking, do to the egr valve acting stupid because of splice pack sp423's mounting bolt being severely rusted causing grounding issues to the egr valve.

 

RIFLEMAN, a quick question for you. You mentioned in your earlier comments that splice pack sp423 also grounds the fuel sending. Since all of us 2nd gen owners are very familiar with floating and erratic fuel gauges on these trucks did cleaning/repairing/relocating this splice pack have any positive effect in having the fuel gauge read more accurate and eliminate any of the infamous floating on your gauge.

 

Yes, it fixed the constant jumping around of the fuel gauge needle, but after the sp423 repair, the gauge reads wrong when it gets below a half of tank, which obviously is a problem with the float sensor itself on the fuel pump assembly in the fuel tank, i'm waiting for just the right day for the fuel pump to give out when it's the most convenient time and i have nothing else to do and i'm in the mood to drop the tank in the driveway

 

Like rifleman, my *** has sprouted roots in the chair infront of the computor while searching threads etc for help. Thanks to him I'm going to take the truck into work, lift it's rear with the forklift, block it & check that grounding harness out. Mine has a very irratic misfire/stumble/fart & the fuel gauge floats around mostly 1/4 tank & under to the point of bottoming out. I put in neutral & the level goes back to where it should be. I think the code was P0446 - fuel sending volts something or another. Sounds like it could be a ground issue seeing as it slowly has gotten worse. Now as for the sputtering & the P0335 CKP volt issue & my late year '02 not having an EGR valve I'm not sure, but I'm willing to try anything at this point. I can't get it on the dyno for tuning until this sputtering is corrected, so needless to say it's aggrivating as well as depressing at times lol.

Thanks again Rifleman!

I'm also going to check the alternator. The volts have been dropping down on occasion, lights dim a bit etc. Replaced the battery last week because it wasn't holding a charge but maybe it was being drained while off. Maybe it wasn't getting a proper charge from the alternator?! Damn electrical demons!

 

Hmmm just a thought - like many other things on these vehicles, after replacing or disconecting something, does that have to go through a relearn procedure?!

 

AC meters - DC meters and Complex Voltages.

Most AC meters expect the user will be measuring sinusoidal AC which has no DC component. Most DC meters expect the user will be measuring steady-state DC.

If a tech needs to measure the AC component or ripple on a DC line (such as alternator output), you need to block the DC component. This can be done with a blocking capacitor of about 10uF and a 100k Ohm resister. Connect one end of the resistor to ground, the + end of the cap to the point to be tested, connect the other end of the resister to the neg end of the cap and connect the AC volt meter across the resistor. To be sure you've got it hooked up right, switch to DC and you should see none or very little (motor turned off).

Now, switch to AC and start the car.

Car alternators have 3 phase windings and 6 diodes which produce a very smooth output. The AC ripple will be fairly small but will increase with heavy load of if the battery is drawing a heavy charge.

If any one diode is open or shorted, AC ripple will be greatly increased. However, even with one or two open diodes, ripple will still drop way down if there is no load what so ever.

 

I believe this is what you're talking about.
Mine seems ok, doesn't move when I try to turn it, kind of hoping that was it. Having the 3" BL sure would make it easy to get to.

 

to rottidog, your problem sounds like it maybe the crank position sensor or the harness to it itself. try looking at the wiring at the sensor to see if its soaked in oil from the front main seal leaking or something like that, and then take out the sensor and look to see if it is damaged in any way, but yea the 2002 has no egr but i havent looked at the wiring schematic for it but my wife has a 2002 and i'll check, i have three different sources to get alot of info from so i'll look tonight to see what that ground is for on your pic!!