About a year ago I was driving and car shut down suddenly and would not start. I tested for a bunch of potential causes and it ended up being my ECM (engine computer) shorted out/went bad (I actually opened it up and saw burnt spot on circuit board). I changed my ECM back then (with a used ECM with matching numbers) and this fixed my previous no start issue. However after changing the ECM out code check engine light no longer came on and obd code readers no longer communicated with car. Car started and ran well for about a year like this though. No back to present. Car shut off again while driving and no start now.
Back to present. Driving on interstate and engine suddenly stopped running. Unable to ever restart and now just crank no start.
Thinking may be ECM again and bought another recycled ECM (again matching numbers) but this time did not resolve issue (I actually bought 3 different matching number used ECMs and none of them have resolved issue).
Now thinking maybe not ECM (but again current set up not throwing codes) and tried to start testing/changing out other items by process of elimination (trying to verify fuel, spark, air, and compression)
-Verified battery is good.
-Tested all fuses and relays and tested good.
-Unscrewed shield and verified timing belt appears to be in place and not damaged.
-Tachometer jumps up some at crank (I'm told this indicates compression).
-Changed spark plugs and verified spark at each of the four coils when cranking.
-Changed Crankshaft position sensor and changed cam shaft position sensor.
-Changed fuel pump assembly and verified pump turning on at car start attempt/crank.
-Sprayed starting fluid into intake manifold and attempted to start and again crank no start.
Also I believe fuel is reaching combustion chamber as I pulled out the recently changed spark plug and it smelled of fuel.
I am not sure what else to try. Based on what I have done it appears I am getting spark, fuel, and I think compression. If its not my ECM is there some other sensor or factor that can throw off timing/fuel, air, spark mixture? I guess it could be some kind of vacuum leak (hidden hose failure or something) but would I get an RPM jump at crank if that were the case?
Any thought or diagnoses would be appreciated.
have the same problem?
Friday, February 26th, 2021 AT 11:34 AM