Hi all! I'm new here and I live in Finland, so I hope you'll understand my grammatical mistakes..!
The reason why I have to ask you about, is that I don’t actually know what to do next. My car is 1991 Pontiac Grand Prix 3.1 VIN:T and engine doesn’t run at all.
Couple weeks ago I think that I have to replace new spark plugs because this is new car for me and I don’t know previous service history. I put a new plugs and that was the beginning for the problems. Before that it runs really good! I’m a car mechanic so I think that I know something about this. (Since then, I have already changed the second one spark plugs.)
So the engine won’t fire up anymore. At this moment it cranks good but won’t start. Sometimes when I try to crank it, the engine hit back like ignition timing would be too early. And sometimes it popping into the intake manifold. Exhaust gas smell like really rich mixture and smoke is gray-black.
Things what has been replaced:
-Repl. new crank position sensor. (there is only one for it)
-Repl. new coolant temperature sensor.
-Repl. new ignition module and also all coils.
-Repl. new fuel pump relay
-Repl. new spark plugs and also tried to new spark plug wire
-Repl. new battery
Things what has been done:
-Cleaned EGR valve.
-Cleaned throttle body.
-Checked all vacuum lines
-Checked timing mark
-Checked injectors resistance, one had to be replaced. Resistance was 5.1 ohm.
-Checked wire harness from ecm to injectors, map.. etc..
-Tested sparks (for all plugs)
-Checked fuel pressue
-Tested 5volt system
-Tested ICM ground and also main power socket (the driver side one socket)
-Tested TPS
-And many little things..
Any idea what to do next? We have sparks. We have fuel pressue. We have power to crank the engine and I have tired to try! All ideas are very welcome! So if you know something, please let me know!
Many thanks,
J-P