New engine start up problems
- Thread starter Blue 2000 TJ
- Start date
New battery 12.86 volts New exhaust from head pipe to tailpipe minus converter All grounds reattached factory positions and scraped clean Thanks for the thoughts
This morning I went to start it and it won't Cranks over had 20# fuel pressure when key turned on jumped to 46# while cranking Would a code PO351,2,3 cause a no start condition? What am I missing Last nite it would start n stop n restart w/o any ressitation It ran a little rough but ran
When you replaced your crank sensor did it have the spacer on it? If it's not spaced correctly, it will make contact with the flexplate.
Yes it did Replaced with SMP part # PC 176 about ready to put orig factory one back in Have to find some things cardboard to put on bottom of old one Thanks for the thoughts
https://www.carparts.com/blog/what-are-short-term-and-long-term-fuel-trims/
This is what he means by fuel trims
Check the wiring to the coil and the wiring that goes behind the valve cover. Unlikely all 3 coils would die at once.
This is what I came across today in my venture. Checked the TPS and was in spec. Replaced the new CPS with the orig one and found something interesting. The SMP part was shorter than the original because the cardboard was still on the end of it. Reinstalled the original one after building a spacer. Still no start. What haven't I touched? The coil rail. Checked the connection good n tight. Pulled the rail off the plugs to check spark plugs and found them gas soaked terribly. Grabbed my old HEI plug tester put it in a boot installed onto rail and turned the motor over and got weak/intermittent spark on 1&6 and 2&5 3&4 looked what I'd call normal but not great. I didn't suspect the coil earlier as it ran not great but ran. So I guess that the code reader was telling the truth so a new rail is in my future as well as another new set of Champions. While I have it this far apart I'll check the CPS to make sure that's in line where it's to be. Maybe someone would enlighten me as to how get the CPS in phase. I'm guessing the motors got to run so your scanner will read 0 degrees? Thanks again for all your insights and thoughts and hopefully next week I'll be able to drive it. "What a concept that" my wife says.
There's no adjustment on the crank sensor, just bolt it in.
The PCM looks at the cam sensor to crank sensor alignment and will tolerate a certain amount of misalignment.
Basically set the engine to TDC on 1 and then align the cam sensor per the FSM. My 06 has a different cam sensor than yours, so not sure what markings yours has. There are usually alignment holes in the base and tone ring that should line up when at TDC.
If your scanner supports the alignment, then fine tune the cam sensor to as close to 0 deg with the crank sensor as possible.
The PCM looks at the cam sensor to crank sensor alignment and will tolerate a certain amount of misalignment.
Basically set the engine to TDC on 1 and then align the cam sensor per the FSM. My 06 has a different cam sensor than yours, so not sure what markings yours has. There are usually alignment holes in the base and tone ring that should line up when at TDC.
If your scanner supports the alignment, then fine tune the cam sensor to as close to 0 deg with the crank sensor as possible.
A new week and a new outcome I hope. Back to my issue and here's where it stands. Took the coil rail off and inserted a spark tester into the boots and got a white spark intermittently around the tester. Found an article on another site regarding testing the coil rail with a ohm meter. So I'm going to try that this am before I run down to buy a new one and test it before installing it. Can you do the same with the Crank sensor and Cam sensor? I know I have fuel, 48# cranking, as the plugs are fuel soaked to the point of replacing them .I have compression by a known good tester. Going to recheck the initial install of the cam sensor/TDC mark. I have a CEL on, dash gauges work except tach when trying to start. I found that my new SMP crank sensor was to short to have the spacer wore off by the crank so I made my own .030 spacer and installed the one that came out of the old motor. Again this was purchased as a non run vehicle with no history other than a hole in the motor where one was not to be. I know I have to have fuel, compression, and spark to make it run. Am I going down the right path in a proper sequence or am I just running in circles? Thank you all for your insight and suggestions.
And timing. Fuel, spark, compression and timing.
I agree with chasing spark especially with wet plugs.
Need an oscilloscope to test Crank and Cam sensors. @hear wrote up how to do it with a $30 Amazon Bluetooth scope. Your scanner might be able to display the wave form.
We've had a couple of folks put Luk flywheels on having issues...I can't recall if they're keyed with the bolt pattern but the gaps in flywheel were in the wrong places for the PCM to get correct timing info. Let me know if you want me to search for that post.
-Mac
I agree with chasing spark especially with wet plugs.
Need an oscilloscope to test Crank and Cam sensors. @hear wrote up how to do it with a $30 Amazon Bluetooth scope. Your scanner might be able to display the wave form.
We've had a couple of folks put Luk flywheels on having issues...I can't recall if they're keyed with the bolt pattern but the gaps in flywheel were in the wrong places for the PCM to get correct timing info. Let me know if you want me to search for that post.
-Mac
Mines automatic used the original I saw the post on the LUK wheels Regarding the sensors do you check with motor running I remember using scope on a running engine
Mac you mentioned timing I was told that timing can't be changed in these engines Maybe I have a different concept of timing as I'm very old school born in early 50's So what is this timing you speak of? Thanks again for your help trying to get it running and sharing your wisdom.
The PCM controls the ignition timing. Nothing to set. The plugs are fired off the crank sensor in pairs. 1 and 6, 2 and 5, 3 and 4.
The mechanical timing of the cam to the crank can be off if the timing chain is off a tooth.
The cam sensor controls the sequential fuel injector timing.
The mechanical timing of the cam to the crank can be off if the timing chain is off a tooth.
The cam sensor controls the sequential fuel injector timing.
Coil rail test With meter set a 20k ohms the secondary where at 14.5to 14.8 within spec as I see it The primary was.01 on all three test spec says .71 to .88 so I say fail Agree/ disagree?
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