car runs bad cold, but seems fine when warmed up

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Tisk Tisk

New Member
Messages
28
Location
san marcos, texas
Hello i just picked up my 3rd sc400 dirt cheap ($2200) because it has a engine problem. When I first start the car in the morning it seems to be running on only a few pistons really ruff idle blue smoke out tailpipe smells strongly of fuel. As it sits there warming up it seems to pick up a few pistons and runs alittle better, and then when its fully up to operating temperature it runs great, faster then my other sc400 with no hesitation!

Ran the check engine codes and it is storing DTC 13 and 41. Since I have another running car sitting next to it I started swapping over components to test for the problem. TPS, IAC, both ignitors, MAF, coils... nothing made any noticeable difference. I have been reading on the forum that code 13 is the rpm circuit which originates from the crank sensor and uses both cam sensors to check the timing. My tach works fine so I assume the crank sensor is working ok, but I don't know about the cam sensors.

My question is first am I looking in the right direction? Has anyone else had this problem before? Is it more likely that the cams sensors are, broken, missing, bent, unplugged, or is it more likely that there is a wiring problem in the harness between the sensors and the ECU? Is it likely that the ECU has a problem?

Since the engine runs so well when its warmed up I can pretty much rule out that there is actually a timing belt problem, or other ignition problem. It seems to me that it must be some logic or sensor problem that either goes away when it gets warm or is only part of the engine warmup sequence.

Any thoughts are greatly appreciated,
-Jake
 

Peewee

New Member
Messages
2,637
Location
Perth, Western Australia
Have you reset the ECU and then rechecked the codes?

Reset the ECU, then check the codes. If anything comes up then its most likely a broken sensor and/or broken wire.
If it only comes up after running then its probably more serious.

41 is TPS error, check the TPS settings against manufacturers specs.


Hard to start could be a faulty CSI timer switch, or a semi blocked CSI.
 

Tisk Tisk

New Member
Messages
28
Location
san marcos, texas
Thanks for the fast reply!
yes i have reset the ecu and the codes both come up immediatly.
i have swapped the TPS with a known good sensor from my other car with no difference. so unless its in the harness id say the DTC 41 is only a symptom and not the true problem.

Thanks again!
-Jake
 
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