Normally I don't ask for it, however I am frustrated at the moment and need some clearer minds.

I replaced the fuel pressure regulator today. 2000 S10-Blazer 4x4 with the 6 injectors and spiders to each piston (CSEFI). I have been fighting a Random miss-fire. I have done a complete tune up, spark plugs, wires, cap and rotor, fuel filter, pvc, and coil within the past 2 months. Lately it runs fine under light trottle, stumbles going up hills, or when you give it moderate peddle. The last two codes were P0305, miss fire in piston #5. That was the quick history.

Fast forward to right now. I got it back together, primed the fuel system, fired it up and let it idle for 1 minute or so. Revd the **** out of it, it idled back down. I went and moved the wifes car so I could back out of the driveway. Put it in reverse and it idled down and died. It didn't want to start, even pumping the peddle like on a carb didn't work. Several attempts and now she doesn't want to crank over.

In the recent past it ran great while in park, I could run any rpms without any trouble (like tonight), once you put it in gear, it would burb some at idle, and the hesitation problem while driving. I did clean the MAP/MAF sensor (which ever I have) and that helped with the idle in gear some.

Sorry for being long winded, just a little frustrated at the moment. Could use some help.
Thanks!!

 

Update.
I pulled the starter and the nose cone had broke off. Put the new starter on and the engine still will not crank over. Almost like something is stopping the engine from turning. And the saga continues.

 

How is your ignition switch doing?

 

We had talked yesterday about this... What did you end up finding when you attempted to turn the motor over manually?

 

Update:
I took the day off from work to work on the truck. Here is what I did.
I cleaned all the starter cables at both ends.
I pulled the upper intake and made sure the spider, fuel pressure regulator, and everything elsewas still together correctly.
Cranked the engine over via the flexplate 4 revolutions in each direction to eliminate a froozen engine or obstruction causing it from cranking over.
Pulled the distributor and it is fine, gear is not cracked, or broken, no teeth missing or chiped or anything like that.
Put everything back together and managed to get it started, reluctantly, even idled, however nothing has really changed. Still a bear to start.
I need to get my IAC and Crank position sensors tested. None of the local autoparts stores can test them. And at $65 for each one I am not about to replace them.
Iwent to our weekly Scout meeting tonight. Long story short, one of the guys who appreciated me for helping the Troop when both of my sons have moved on has an OBDII diagnostic scanner he is going to let me borrow. Hopefully I can get it to run and hook up that scanner and see whats going on. Anybody know where I can find the parameters, settings, acceptable readings for my engine, CSEFI 4.3L V6?

 

Update:
Now I have a new problem, the engine doesnt want to start. I smell gas fumes, and it cranks, and cranks, and cranks, once it starts running it runs like crap. give it gas and it dies.
I did pull the distributor, however never turned the crank and put the distrib back in the way it came out. I marked the rotor to the housing and the housing to the engine, also the housing has a square base and I never removed the holddown bracket from the housing, I am 99% positive I got it back in correctly.

I also replaced the fuel pressure regulator. I pulled the upper intake off, and did the work again. Still get the fuel smell after cranking it over. I gather I disconnected afuel vapor line, however I dont know where to find that, or where to find the charcoal canister.

I also cleaned the IAC. Pulled the pintle out, cleaned it and put it back together.
I also pulled the Crank Position sensor to get it tested, only to find out none of the local autoparts stores can test it. I dont have a digital multimeter. Cranked the engine over a few times withouth the sensro in place before I realized I left it out. Put it back in and the engine managed to start, run like crap, gave it some gas, it backfired and died.

What am I missing, what did I do wrong?

I did manage to borrow a scan tool. Information is limited due to disconnecting the battery and only getting it to run really crappy, however it never ran with the scanner hooked up.
I get a P1351 IC Ciruit- High Voltage, and a P0300 Multiple Random Missfires, then the P1351 again. No other codes stored.

Fuel system Mon- OK
Comp Component- OK
Catalyst Mon - Inc
Htd Catalyst n/a
EVAP System Mon - Inc
Oxygen Sensror Mon- Inc
Oxygen Sensor Htr- Inc

VIEW DATA PID
Abslt TPS- 0%
Engine RPM- 0
Calc Laod- .8%
MAF- 1.92 gr/s
MAP- 100 KPa
Coolant- 18 *C
IAT- 17 *C
IGN Advance- 0 deg
LT Ftrm1- 0%
ST Ftrm1- 0%
LT Ftrm2- 0%
ST Ftrm2- 0%
Speed- 0 KPa
Fuel System 1- Open
Fuel System 2- Open
O2 S11- .59v second reading .52 v
ST Ftrm11- 0%
O2 S13- .47v second reading .525v
O2 S21- .57v second reading .510v
ST Ftrm21- 0%
PTO Status- Disen
OBD2 Stat- CA

Freeze Data
Abslt TPS- 0%
Engine RPM- 127
Calc Load- 1.6%
MAF- 2.88 gr/s
MAP- 98 KPa
Coolant- 21*c
LT Ftrm1- 0%
ST Ftrm1- 0%
LT Ftrm2- 0%
ST Ftrm2- 0%
Speed- 0 KPH
Fuel System 1- Open
Fuel System 2- Open

Those are all the readings off the scanner. Scanners are new to me. Any idea whats going on?
Tomorrow I take the battery and have it tested. I hooked up my charger to the battery for a couple hours tonight after work, disconnected it, and then ran the tests, and managed to start the truck once, after that everything would go dead when I turned the key to start and the starter would go click. Even had my rear hatch pop open like I pushed the dash mounted switch.

 

will kick this back up to the top for ya. you might try PM'ing lastcoupe, he is one of our ASE mechanics.

 

Thanks. I did, and I emailed Kordog as well.
Then I did a web search for P1351. You'll never guess what I found?
https://blazerforum.com/m_59993/tm.htm

My original thread from the day I started having my engine problems. Guess who was the first person to reply (last Coupe), and I'd be willing to bet a million to 1 his first post was the correct answer. I even had my local AZ guy test the ICM and it came out OK. Maybe it was an intermittent problem, maybe it is the wiring. Damn ground squirell did eat nuts on the back side of my engine and left his crumbs. I think I fixed his band wagon though. I think he drank the anti-freeze I had sitting in a container on my garage floor. If it wasn;t him, then something else crawled into my garage and died. I just havent search for nor found the carcas yet, but I can smell it. Sorry I digress.

At least I have a no start condition and that make it easy to find the problem. I also found another thread where the guy basically said you have a shorted out wire in the ignition circuit. Which sounds like what is happening when I crank the kjey to start. Everything goes dead, lights, dash, everything, then the back hatch pops open. Not sure why that happens. But at least I have some direction now.
Still looking for any and all feedback. This has been one long thorn in my side. Started back on January 20th.

Alot of that didn't make much snese to me back then, however most of it does now. Altough I do have a few questions.
Could someone explain this to me in laymens terms?

 

Well, when i had an issue similar to your no-start symptoms, turned out I had a cracked Dist cap, and i had just replaced it about1 month prior. I found a nice guy at autozone who let me pay for a part, i payed for the icm, and take it home and putoin on the truck to see if that was the culprit, and if not, return it and get another part.

On the VCM (vehicle control module) ECP, PCM, whatever you call it, was stating, probe the two wires Pin 9 and pin 18. basically, connect the digital multi-meter to those two wires, (in DC mode) and you will have a voltage present. then start moving the other connectors inline with the PCM, ECM, VCM or whatever, and if you have a short or a broken wire, the voltage will change.

This could be a problem with ICM, ignition switch, or just wiring. check all the wires at the starter and the ignition switch. just for some reason, im thinking ICM, but thats just a feeling, Im not great at the tech side of your trucks, moreso the audio.

But i would have no problem popping off the CaP (same as yours, and the ICM) as they are both in working condition and ship them to ya, and then you could see if they were the problem, and then be able to buy them. B/C im not driving it much, since we got another car, she drives the honda, and i drive the jeep.

 

Thanks for the offer. I doubt I will take you up on it though.
I think tonight I will get the battery tested and the ICM.

How do I tell the pin numbers? There are at least 3 sets of wiring harnesses that hook up to the engine computer. My Haynes book doesn't show a diagram of the puter, heck it doesn't even have a wiring diagram for the CSEFI engine. The wiring harnesses are labeled White, Black, and I dont know what, or something to that effect. About the only one I remember is white. and I think the other is black, and I didn't look at the one underneath.