1990 240sx cranks, but does not fire!

[Bay Dog]

The car cranks and cranks, but does not fire. I looked at a checklist for "Hard starting when Cold" (from the 240sx.org web page) and here is what I have done.1. Replaced Fuel filter.2. Replaced Spark plugs.3. Replaced Plug wires from distributor to plugs and ignition coil to distributor.4. Replaced ignition coil. Got one from a salvage yard, but it does put out better spark then the one I had to begin with.(All of this has made a considerable difference in how the car cranks. It cranks MUCH stronger.)5. Checked ECM for codes. It displayed code 13 (Engine Temperature Sensor Circuit), and code 21 (Ignition signal missing in primary coil).

I do have a Chiltons manual, but it doesn't address the codes and where to begin with them. I am unsure as to where the engine temperature circuit is and I assume the ignition signal missing code means that my salvage yard coil is bad. ???

I have noticed there does seem to be a minimal amount of exhaust leaving the tailpipe when cranking so I believe this rules out the exhaust system as the issue.

I did pull the new plugs out after putting them in, so I have to believe the fuel pump and injectors are still working correctly. Could I be one of those rare cases where the ECU is the issue?

Any help would be GREATLY appreciated. Thank you!

[slw240sx]

wires on in correct order ? fuel pump working ? filter (fuel) working ?

[QuinGarcia]

just because your ecu says read that code about the ingition does not mean that your junkyard coil is bad. The ecu stores old codes until you erase them manually or leave the battery disconnected for over 24 hours. Your old coil could have left the code, and it is still there even though the new coil could be fine.

[drjohn]

Do you have fuel pressure, compression, injector pulse,are the injectors opening ???

[capt_dalton]

Ya gotta have fuel and ya gotta have fire. If you've proven to yourself that beyond a shadow of a doubt you have fire at every cylinder in the proper sequence, that one is out of the picture. You've demostrated to yourself that there is fuel being delivered to the injection system and to the fuel rail and to the injectors? Then that's not a problem either. Very weird things hapeened on a chevrolet 350 I once owned. After a particularly "fun" evening of driving wrecklessly, I encountered a very pronounced miss, like 4 out of eight firing. As it turned out, my crank was broken clean in half. What if, your crank is broken? Have you tried performing a compression check on every cylinder? Manual or automatic transmission? If auto, neutral safety switch? Just some weird guesses to give you something else to look at.

Good Luck in your dilema.Capt. Dalton

[Bay Dog]

Thank you all for your suggestions. It ended up being a myriad of things. Whomever replaced the distrib. mounted it 180 degree different, so the wires were all screwed up. And the ignition coil needed replacing. It seems to run fine now. Except I have noticed that when I start it and it tries to die backing up, if I don't immediately push in the clutch and rev the engine, it won't start. Just like before. If it dies before I get it into 2nd gear, I'm done.

Not too sure what this is, but it does concern me a bit. Possible faulty clutch switch when starting??

Anyway, thanks again!!