History
I put it on the road. Drove it daily for about 3 months and ran perfect. One day I pulled into a parking place and shut it off. Did my thing, got back in and started it, backed out of the space, put it in drive. All was normal. I drove 50 feet and the motor popped out the throttle body once and wanted to shut down. I put my foot to the floor and it stayed running but acted like it was running on 4 cylinders. Let my foot off and it shut down. Never to start again.
Symptoms
Crank it over and it loads out every revolution in the same place. For a split second sometimes it will fire enough to kick the starter out and then the starter slams right back in. For the older mechanics the symptom is exactly like the timing is over advanced just to the edge of not starting. If I were to hear it cranking on a 1970s car I would say the timing was way over advanced.
Work done
Since the symptom seems to be timing related I have replaced,
Crank sensor
Cam sensor
All 4 O2 sensors
Ignition module
Map sensor
Cleaned MAF sensor and tried a back up
Tests done
1 Checked fuel pressure, right on spec.
2 Checked for pinched or chafed harness
3 Tested spark
4 Compression test 145 to 170 with in 15% and only has about 3000 miles on new motor.
Thought maybe timing chain or bent valve issue but compression is perfect.
5 Tried different PCM, does the same thing
6 Checked all fuses
7 Checked all grounds
8 Pulled distributor to check teeth and gear pin and visually confirmed its rotating normal.
9 Tried starting fluid while cranking to see if the new MPI conversion went bad but any fuel at all added instantly floods it.
I thought maybe the cam for the crank sensor may have twisted but I cant wrap my head around that cause it on a key and sandwiched behind the harmonic. Grasping at straws.
At this point My plan is to get a timing light and see what the actual timing is when cranking and pull the whole harness and check every wire for continuity end to end from the PCM. My gut is saying its something simple and Im not seeing it.
An ideas would be awesome cause this is blowing my mind. Everything tested says this thing should run. Thanx!
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Saturday, June 12th, 2021 AT 12:35 PM