03 Duratec Won't Start, misfires

RogueInLA · Oct 23, 2014

Friend bought a 2003 Ranger with 2.3L Duratec, supposedly a rebuilt engine, but was never run. Tried to start it and it misfired badly, kicking back against the starter. Compression was 150/155/140/148. Pulled the valve cover, set the stop bolt in R/H front, and the cams were approx 2 teeth off, reset the cams, put the timing bar across the back, the Harmonic balancer was about 2 inches off also, so reindexed that, put a bolt thru the balancer into the timing cover, and tightened everything back up. Turned the motor over twice by hand, everything lined up properly. Compression is now 170/170/155/155. However, the motor still misfires just like before. By pulling plug wires able to determine that #s 1 2 and 3 are misfiring. Plugs were totally black fouled, so put in new plugs. I believe a bad cam or crank sensor would give no spark, not bad spark, right? Anyone have any experience with this? I'm certain from all I can see that the valve timing is correct (engine against stop bolt, cam bar in place, bolt thru balancer). I've been checking wiring, but I'm baffled at this point. I'm looking for crossed/bare wires, does anyone have a wiring diagram for this truck? 2.3L Duratec with manual trans.

Thanks in advance

orangealpine · Nov 3, 2014

Black, fouled plugs indicate too much fuel. So the question becomes what would cause the computer to dump fuel into the engine while cranking? The only thing I can think of is a bad or disconnected sensor. Unfortunately, that's as far as I can extend my"wisdom". The manifold absolute pressure sensor is my best (only) guess, especially as I know zero about how the computer uses that information.

However, the computer is supposed to cut fuel while cranking the engine if the throttle is wide open. Have you tired that?

Bill

dla · Nov 11, 2014

RogueInLA said:
Friend bought a 2003 Ranger with 2.3L Duratec, supposedly a rebuilt engine, but was never run. Tried to start it and it misfired badly, kicking back against the starter. Compression was 150/155/140/148. Pulled the valve cover, set the stop bolt in R/H front, and the cams were approx 2 teeth off, reset the cams, put the timing bar across the back, the Harmonic balancer was about 2 inches off also, so reindexed that, put a bolt thru the balancer into the timing cover, and tightened everything back up. Turned the motor over twice by hand, everything lined up properly. Compression is now 170/170/155/155. However, the motor still misfires just like before. By pulling plug wires able to determine that #s 1 2 and 3 are misfiring. Plugs were totally black fouled, so put in new plugs. I believe a bad cam or crank sensor would give no spark, not bad spark, right? Anyone have any experience with this? I'm certain from all I can see that the valve timing is correct (engine against stop bolt, cam bar in place, bolt thru balancer). I've been checking wiring, but I'm baffled at this point. I'm looking for crossed/bare wires, does anyone have a wiring diagram for this truck? 2.3L Duratec with manual trans.

Thanks in advance

Almost sounds like you are 180* off. I'd get another set of eyes to check your timing.

03 Duratec Won't Start, misfires

RogueInLA

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orangealpine

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dla

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