The basics:

• 1998 Blazer 4x4 4.3 V-6
• Self installed a remanufactured engine.
• Replaced nearly every sensor/switch, gasket, plugs & wires, radiator, alternator, water pump, serpentine belt, cap & rotor
  also a few months ago I replaced a/c compressor
  didn't replace PS pump, fan/fan clutch, spider injector (yet)
• All plugs are getting spark
• It runs rough and sounds like a diesel.
• 1 plug is "cleaner" than the others (also happens to be cyl no. 1)
• engine oil smells of gas on the dipstick
• Slight tapping sound in vicinity of "dead" cylinder, not sure, hard to hear over other noises
• The Check Gages (Gauges) light is on and has been since first start
• Oil Pressure gauge reads ZERO
• Oil warning light is NOT on
• CEL is NOT on
• no DTC's on my scan tool
• pictures of spark plugs are here

Feel free to skip next 3 paragraphs

I "blew" my original engine at 148,4xx mi. It was my fault, running it at close to 100 mph and ~5000 rpm for a few minutes (I know, not smart to do, never mind doing it on public roads). Anyhow, I bought a remanufactured engine/long block from Advance Auto Parts (friend got me 20% off) FWIW the core of the part number is same on AutoZone, O'Reilly, Napa, etc. as in they all come from the same manufacturer. I really wish that three was a list is everything needed but not included with a reman engine.

After FINALLY figuring out that there were 2 timing marks on the cover and why, she came to life. I immediately knew that something wasn't right. As my friend says, it ran like a bag of @$$#0£€$. I ignored it because it had been almost 2 months since I had driven her & I was really tired of driving my buddy's 93 Mercury Sable with so many problems of its own. It ran rough but it ran. Drove around the block a couple times, and other than rough running everything seemed fine. I either didn't notice or ignored the irregular shifting of the transmission. (At least the trans is still under warranty after last year's trip to Aamco.)

It sounded like a diesel but I drove it for a week (about 220 miles) while researching the problem, double checking and adjusting this or that, replacing the alternator that failed coincidentally. Tonight, I was finally able to get back into my buddy's garage and pull the plugs. One spark plug looks different than the other 5 (pics here). It shows some signs of being fired and it is getting spark but there is no carbon or soot like on the other 5. There is gas in the oil :-(

The paperwork that came with the engine said that rockers, heads, etc. had been installed and torqued at the factory and removing the heads was not needed and IIRC, could void the warranty(?)

Since I have spark, fuel and, I assume air, I should be getting combustion, right? I'm guessing that I'm not getting compression. I'll buy a compression tester when I get a chance, I've never needed one before. Anyway, what would be the leading causes of a cylinder with no compression in a "new" engine? What problems would be fatal? It's not an interference engine, is it?

If it turns out to be fairly minor, do you think it would be worth the hassle to file a warranty claim since it is technically in my female friends' name (to get employee discount)?


ps
Yes, I do have some VERY good friends to let me use their employee discount, let me take up a garage stall and have free range and, loan me a car for 2 months at no cost. I am extremely grateful to have them in my life.

 

Basically, I want to know where to look/what to look for when I decide to void the warranty and pull the heads

 

You want to void the warranty?

 

I'm not sure if it would cause the type of problems stated, but one thing the experts on here say is that while the engine may run, it will not run correctly without a Crankshaft (or rather CASE) Relearn. You can end up getting crossfire in the distributor because the camshaft retard is not correct and the Camshaft and Crankshaft position sensors are not in "harmony" (my word, not theirs). Did you have the CASE Relearn done?

 

I've never heard of a Crankshaft/CASE Relearn

Also, I don't want to void the warranty but many companies will void warranties in a heartbeat if they've been "transferred"

 

Well I have several of the experts in this forum "learning" me about it But I am getting ready to put a reman back into my '98 truck. We probably have the same engine from the same "manufacturer" (your right, all the auto parts store use the company...they just put different names on the engines relative to the specific chain).

The Crankshaft relearn is a must and it will not void your warranty. It aligns the Crankshaft Position Sensor and the Camshaft Position Sensor so everything fires correctly and in the right spots. If the relearn is not done, and the last relearn data is being used (it's burned into the PCM's memory until the next relearn) the PCM is using old and probably now wrong data "every adjustment and command that the PCM makes is wrong" (direct quote from Captain Hook).

EDIT: BTW, the relearn must be done with a capable scan tool (like a Tech II that the GM Dealer's use for example).

 

Instead of trying to stumble all over myself...here it is in detail (from the Hook)...but...I can't tell you for certain that not doing the relearn is causing all the problems you're having...just throwing it out there because I know it has to be done:

The CKP sensor creates a magnetic field when voltage is applied to it. The field is directed at the tone ring. The tone ring on the front of the crankshaft has 3 "windows".




Each time a window passes the sensor, it breaks the magnetic field and the sensor creates a pulse. The same function that points and a condenser had inside the distributor years ago, make and break a circuit. Each individual sensor has a unique spot where it is focused. The crankshaft position sensor relearn tells the PCM precisely where it's focused, from that, the PCM calculates exactly where the crankshaft is in its rotation. Through simple mathematics the PCM can calculate exactly where each piston is, what cycle it's on, (intake, compression, power, exhaust) and when to command the ignition module to fire the ignition coil. 120 degrees of crank revolution later, the next cylinder is fired.


When the relearn is performed, the calibration data is burned to a memory file in the PCM. It is the "benchmark" or "ground zero" for everything else. Everything depends on exactly where the crankshaft is in its rotation. If the relearn data is wrong, every adjustment and command that the PCM makes is wrong. Disconnecting the battery or clearing all memories does not affect it. The data remains in the file until the next relearn is performed.

If the CKP sensor and or timing cover are moved, removed, replaced or disturbed in any way, the CKP relearn must be done because the focus point has been changed. If none of that stuff has been disturbed, there's no reason to do the CKP relearn.

CMP retard: Right off the bat, the term is totally misleading, but GM didn't ask me what my thoughts were As far as I'm concerned, it should be called Camshaft Position Sensor Alignment, cuz that's exactly what it is. It aligns the sensor with the camshaft. The PCM uses CMP data along with CKP data to detect and accurately identify cylinder misfire. The PCM detects irregularities in camshaft speed which indicates a misfire. On a side note: timing chains naturally have a certain amount of slack so the cam does not rotate perfectly smooth. Rotating the distributor housing is how the CMP retard adjustment is done. It also positions the terminals inside the cap so the rotor segment is lined up with them when the ignition coil fires. When the PCM applies ignition advance, it fires each cylinder earlier which increases the gap between the segment and the terminal. If CMP retard is out of spec, the gap gets too large and the spark can jump to the wrong terminal. This is called crossfire, which equals misfire. The farther off CMP retard is, the more crossfire there is. If it's out of spec, you may or may not feel the misfire, and the PCM may or may not set a DTC, but it's going on. If it's off far enough, it will set P0300 through P0306 DTC's.

Tid bits:
If the distributor hold down bolt is disturbed, CMP retard needs to be checked/adjusted.

When CMP retard is adjusted correctly, you can unplug the CMP sensor and the engine will start and run just fine. With this in mind, the CMP can not cause a no start condition. A DTC will be set in memory, the SES light will come on, and cylinder misfire detection is disabled.

Rotating the distributor does not affect ignition timing. All it does is increase the gap in the cap, and with the speed of the spark, it jumps the gap at the speed of light, 186,000 miles per second.

The CKP and CMP sensors are 100% accurate up to 10Krpm. Cam rotates at half crank, so that would be 20K engine rpm! Should be accurate enough

 

So I need to start by going to my guy at AAMCO and ask him to reprogram the PCM by doing a "CMP Retard" or "Camshaft Position Sensor Alignment/Relearn". Am I getting that right?
And if they don't have a clue or the right scan tool, I'll go to the dealer where they charge to lay eyes on it, to turn the key and, to open the hood.

Also, rockp2, is there a specific thread you could link to that you are using to "git yer learnin' on" from Capt. Hook and other forum experts or is it an email correspondence program?

 

Not really...the way your putting it. It's not a reprogram of the PCM like someone normally thinks. You would just go in and tell them that you replaced the engine and you need a crankshaft position sensor relearn done (or CASE). Just insure they know what they're talking about and don't have them work off instructions you give them. Go to another shop if they are not smart on Blazer relearns. They do this through the OBDII port.

EDIT: Also, what brand secondary ignition parts did you use? These trucks are very touchy about using AC Delco for you cap, rotor, wires. Look at the DIY Tech forums to learn a bunch.

 

I used a BWD cap & rotor