Help please
#1
Help please
I have a 2001 Chevy Blazer 4x4 LT with 173367 miles. I replaced plugs, wires, and Distributor in March, no issues, then 2 weeks ago I had the crankshaft and camshaft position sensor codes set off, so I checked the harnesses and found they was good but so I did a relearn on the crankshaft sensor and got into all kinds of crap. Got a P0300 after running through a new MAP and MAF sensors, new cap and rotor (AC Delco), new spider and intake gaskets as the original spider was all kinds of screwed up, new crankshaft sensor also as the end was grooved out by the reluctor wheel. My misfires seem to be on bank 1 (1,3&5 cylinders) with a few on the bank 2 (2 & 6). I am stumped my next step is to check fuel pressure and compression test. I have noticed the Camshaft Sensor Retard is -9 degrees. Also replaced all 3 O2 sensors as they looks fried like burnt bacon.
#2
That's a mouth full. Lets take this oneish issue at a time:
George
- What brand crankshaft sensor did you install?
- Did you inspect the reluctor wheel for damage from impact?
- Did you shim the new sensor as needed for proper clearance?
- Did you do a relearn after the new sensor was installed? Did the process complete correctly?
- Did you check the reference voltage and ground at the sensor?
- You need to get CMP retard in spec
George
#3
That's a mouth full. Lets take this oneish issue at a time:
George
- What brand crankshaft sensor did you install?
- Did you inspect the reluctor wheel for damage from impact?
- Did you shim the new sensor as needed for proper clearance?
- Did you do a relearn after the new sensor was installed? Did the process complete correctly?
- Did you check the reference voltage and ground at the sensor?
- You need to get CMP retard in spec
George
2) No I forgot to will be checking that when I dive back into it again
3) Yes I did
4) Yes and the relearn took according to the scanner
5) Yes I did check for that and continuity also at both ends of the harness
6) How do I go about getting the CAM Retard back in spec? Not much room to wok back there and I have large hands..
Note: I have pulled the plugs and the ends are black, not oily from engine oil, but black like burnt toast..
#4
Either wallow out the distr hold down bolt opening to make it oval to get more distr rotation or pry the original off and replace it with an adjustable hold down as I did:
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
Your also going to need to do a fuel pressure leak down test.
George
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
Your also going to need to do a fuel pressure leak down test.
George
Last edited by GeorgeLG; 05-13-2024 at 04:44 PM.
#5
[QUOTE=GeorgeLG;753019]Either wallow out the distr hold down bolt opening to make it oval to get more distr rotation or pry the original off and replace it with an adjustable hold down as I did:
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
You’re also going to need to do a fuel pressure leak down test.
George
The plugs where black before the O2 sensors as the Fuel Spider (which was the original) failed so it was replaced with the AC Delco (MFI version).
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
You’re also going to need to do a fuel pressure leak down test.
George
The plugs where black before the O2 sensors as the Fuel Spider (which was the original) failed so it was replaced with the AC Delco (MFI version).
#6
[QUOTE=matthewsjeremiah1983;753020][QUOTE=GeorgeLG;753019]Either wallow out the distr hold down bolt opening to make it oval to get more distr rotation or pry the original off and replace it with an adjustable hold down as I did:
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
You’re also going to need to do a fuel pressure leak down test.
George
The plugs were black before the O2 sensors as the Fuel Spider (which was the original) failed so it was replaced with the AC Delco (MFI version).
**Note: I just got back to working on it today in between rains and figured out my reluctor wheel for the cam is of set, and I can’t pull it off to re clock it, this I know will fix the timing issue with the camshaft
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
You’re also going to need to do a fuel pressure leak down test.
George
The plugs were black before the O2 sensors as the Fuel Spider (which was the original) failed so it was replaced with the AC Delco (MFI version).
**Note: I just got back to working on it today in between rains and figured out my reluctor wheel for the cam is of set, and I can’t pull it off to re clock it, this I know will fix the timing issue with the camshaft
#7
[QUOTE=matthewsjeremiah1983;753062][QUOTE=matthewsjeremiah1983;753020][QUOTE=GeorgeLG;753019]Either wallow out the distr hold down bolt opening to make it oval to get more distr rotation or pry the original off and replace it with an adjustable hold down as I did:
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
You’re also going to need to do a fuel pressure leak down test.
George
The plugs were black before the O2 sensors as the Fuel Spider (which was the original) failed so it was replaced with the AC Delco (MFI version).
**Note: I just got back to working on it today in between rains and figured out my reluctor wheel for the cam is of set, and I can’t pull it off to re clock it, this I know will fix the timing issue with the camshaft
George
I got the blazer put back together and no misfires and got the crank sensor relearned again. Below is my fuel trim numbers so far:
Sounds like your running rich. Did those plugs turn black before or after the new O2 sensors?
What are your 4 fuel trim numbers?
You’re also going to need to do a fuel pressure leak down test.
George
The plugs were black before the O2 sensors as the Fuel Spider (which was the original) failed so it was replaced with the AC Delco (MFI version).
**Note: I just got back to working on it today in between rains and figured out my reluctor wheel for the cam is of set, and I can’t pull it off to re clock it, this I know will fix the timing issue with the camshaft
George
I got the blazer put back together and no misfires and got the crank sensor relearned again. Below is my fuel trim numbers so far:
#8
Those fuel trim numbers are a mess. The engine computer is trying to compensate for a perceived rich condition.
George
- Can your graph you O2 sensors so that we can see if they are switching OK?
- In the morning when the truck is cold go to key on and capture: IAT, ECT, Baro or MAP and note the ambient conditions for temp and atmospheric pressure
- What is your MAF value at warm idle and again at the moment of a full throttle 1-2 shift
- Does the truck warm up to 190F when you are driving?
- We are going to need that fuel pressure leak down test
George
#9
This is what I have so far, I am going to do a leak down test but the issue I a now running into is this engine will not fire again. I can crank all day long but it’s hits hard one time and then nothing