Expert: Roland Finston - 6/9/2011

Question
QUESTION: I replaced my engine in my 02 Chrysler 300M 3.5(G) engine with a 05 3.5 engine.Couldn't find any 02's with low mileage. At any rate the engine turns over real good, has fire to spark plugs but just will not start.Where do I start to look for what might be wrong. I've checked all my manuals but couldn't come up with anything.Hope you can help. Thanks Ron

ANSWER: Hi Ron,
If you have spark, do you have fuel? Do you hear the fuel pump run when you turn the key to the run position, for a about 1 second? It should do that, and then hum again when you turn the key to the start position.
The other way to look more globally would be to do a fault code readout. Turn the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapased time. Then watch the odometer window to see the mileage reading change to show 4-digit numbers preceded by a P. Let me me know the numbers and we'll go from there.
Roland

---------- FOLLOW-UP ----------

QUESTION: OK, Here is what came up. P-660, P-113, P-123

Answer
Hi Ron,
The 0660 is about the manifold tuning valve which may not be present in the '05 engine (unless it is a high output version) whereas it was in your '02. I would doubt that code/difference in the valve would prevent starting.
The 0113 says the signal voltage on the intake air temp sensor is too high, and the 0123 says the voltage on the throttle position sensor signal wire is too high. The air sensor is a variable resistor between the ecm pin 30 and sensor ground at pin 27. while the throttle position sensor is a voltage divider who is operated by a 5v signal on pin 1 of the sensor that originates at pin 29 of the ecm, has the same sensor ground wire on pin 3 and the signal is on pin 2 connected to ecm 21. I would look at those two sensors' harness wires for possible melt/short situation, check that the tps shows 5 volts on pin 1, and verify that the black/light blue ground wires at the sensors are showing 0V compared to ground. Somehow there is either a higher than normal 5v supply due to a short, or a common sensor ground that has some voltage on it or maybe is disconnected due to a short/or an open wire. Those situations could very well cause a no start.
Did you hear the fuel pump?
Roland
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