awesomenick

So, I'm running out of ideas of things I should look for on my 200sx with a CA20E. I got it in a trade a few months ago, and when I first got it it would run when it was cold, but not when it was hot. For example, I'd get in and start it, and it would run perfect, through the whole RPM range too. Then, I'd get to my destination, and it would just crank forever, and never start. Once I'd waited for a while it would start up, but it ran poorly. I would have to have it at WOT and it would run okay for part of a second, then feel like it was dying. Really jerky.

Some things the previous owner had replaced are spark plugs on the intake and exhaust side and intake side. He put on new Bosch spark plug wires, new cap and rotor, new distributor, and a new fuel filter. I recently replaced the coolant temperature sensor, but I don't think that is the problem.

I checked to see that it was getting fuel after the filter, and it is. The filter is also the correct way, not backwards. I pulled the exhaust side spark plugs, which are the main ones, and they're completely black, so it is getting fuel. I also pulled the pump out of the tank to see the tank's condition, and it looks brand new. Nothing in there should be giving me any problems. I can see the bottom and there are NO particles in it.

First, I used a spark plug wire tester to check for spark, of course I didn't totally trust it's results so I pulled the plugs out and grounded them, they make a spark. I also checked the gap and it's right. I made sure each wire was in the correct spot on the distributor as well, all of it is fine. Although they spark, I was wondering if it was a weak spark, so I tried using the MSD coil from my s13 in it, and it still had the same problems. I only tired the coil for the spark plugs on the exhaust side.

As far as air goes, I'm not sure how to find out. It uses an AFM rather than a MAF, and I don't know what to do to check it. The flap inside opens, and I checked that the connections inside were all good. It appears that it should work.

Now, a few things I haven't checked are the igniter, and the ECM. Just because I don't have spares lying around, and don't want to dump money into a CA20, when I have a spare KA lying around I could use. I was reading online about people having troubles with their igniters having a small break in them so that when they heat up they don't make a connection anymore, and when they're cold they do. The ECM is hard(ish) to come by for cheap, since I can't find an S12 in the local junkyards. Maybe the Stanza ECU will work, but I haven't confirmed it.

The ECM is giving a load signal "code." I'm not 100% sure what that means, but another person on club s12 had a problem with load signal, and his car was able to start with the a/c on. Mine doesn't have a/c, so I can't try that.

My car runs fine on ether, so that makes me think distributor timing is okay. I don't want to mess with it too much since it ran fine before. My theory right now is that I should go find an igniter in a yard somewhere, and try it in my car, along with new spark plugs. Maybe throw in two new coils while I'm at it, and see how it goes. Maybe it had a break inside of it, and now has gotten too bad to work at all, I'm not experienced enough to know about that. I started downloading the FSM, so maybe I'll be able to figure it out that way soon too.

Anyways, If you took the time to read all of this and have an idea. Thank you. -Nick

devnull

VG-swap!

Does it have a power steering pressure switch? That should bump up the idle like the A/C does.

I want to say it's an idle air controller problem. Not sure on your engine but on a lot of nissans it's temperature operated. It could be stuck in the warm position.

silver_s13

If your car "runs fine on ether" than its probably a fuel related problem. DO NOT spray ether into your intake. It is BAD for your engine. I don't care what anyone else says. Try pouring a little gas in the intake and see if it starts. If it does then its a fuel problem. Just because your fuel pump looks new doesn't mean its good. Its essentially in a cave for all its life hanging from the ceiling so its always going to "look" fairly good. As far as the runs fine when cold and doesn't start when hot situation that could be your ignition module, or fuel pump. Put a little gas behind the throttle body directly into the intake to determine which it is. Good Luck!

projectRDM

CTS? I don't know much about the early Nissan stuff but a bad CTS on newer cars would lead the ECU to think it's still in the cold fuel map, dumping fuel and running rich. That would lead to hard starting and poor power delivery. It's an easy thing to swap too.

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Hillkill

Check out Club-S12.org The people there know your engine.

awesomenick

Thank you for your replies.

Project RDM, that's what I was thinking too. But I changed it out a few days ago, and didn't have any luck. It could have been part of the problem. I wish I knew how much the ECU relied on the CTS on these, I just got the FSM for it so I'm going to start looking through it.

silver_s13, it could be fuel related, but I'm doubtful because the spark plugs have signs that it's been running seriously rich. Like I stated before, I have fuel pressure up to the rail.

devnull, I hadn't considered the IACV, maybe I'll mess with that a little.

and Hillkill, believe me I've spent a lot of time on there searching. Maybe I'll make a post now.