help with ca18det in 200sx, gremlins

[ca18det240hatch]

Welll i just helped a friend swap in a ca18det into his s12, got all the new relays wired, etc. Wiring is correct, im sure of it. The problem is this, the car will rev to like 4500 rpm and then go back and forth between that and 4000rpm (im guessing, no tach you know) and break up, backfire, etc. It had the problem, so i checked the timing, it was 2 teeth off on both cogs, so i redid it, now its dead on, problem is, same problem, altho it sounds a bit healthier

We have tried a different ecu, no change, different maf, no change, so whats next.....

could this maybe be a coilpack problem? Injector problem? Heres another funny thing, it idles better with the maf unplugged than it does with it plugged in, and i can rule out boost leak im pretty sure because for diagnostics purposes we went straight from the turbo outlet to the throttle body, bypassing any intercooler piping.

any ideas guys? Thanks alot in advance.

[Myetball]

Sounds alot like a fuel supply problem. Did you put a new pump in or still running stock pump?

[boost_boy]

Welll i just helped a friend swap in a ca18det into his s12, got all the new relays wired, etc. Wiring is correct, im sure of it. The problem is this, the car will rev to like 4500 rpm and then go back and forth between that and 4000rpm (im guessing, no tach you know) and break up, backfire, etc. It had the problem, so i checked the timing, it was 2 teeth off on both cogs, so i redid it, now its dead on, problem is, same problem, altho it sounds a bit healthier

We have tried a different ecu, no change, different maf, no change, so whats next.....

could this maybe be a coilpack problem? Injector problem? Heres another funny thing, it idles better with the maf unplugged than it does with it plugged in, and i can rule out boost leak im pretty sure because for diagnostics purposes we went straight from the turbo outlet to the throttle body, bypassing any intercooler piping.

any ideas guys? Thanks alot in advance.

Check for your boost leaks, check for issues with the crank angle sensor, check your grounds, and get the tach hooked-up correctly or get it repaired.

Dee

[Tr0uble]

Don't mean to be a jackass but this sounds identical to at least 2 other guy's on here.





Also whoever figures it out first help the others out So igniter chip is the problem eh?
Modified by Tr0uble at 2:37 AM 8/27/2007

[boost_boy]

Don't mean to be a jackass but this sounds identical to at least 2 other guy's on here.





Also whoever figures it out first help the others out

When someone tells you they've done all the complicated stuff correctly, that stumps the rest of us. Unfortunately, we are not there to properly diagnose the problem, but I'm very sure it's something simple or something botched. These guys are not the first and sure as hell won't be the last. Dee

[trevr]

Had similar issue on my engine, but wasn't able to rev much over 3k rpms. Had a faulty igniter chip, which was not firing cylinder #1.

Also, my ca18det does not like to rev when its cold. It purrs like a kitten when it is warmed to operating temperature. Quite sure this is because I'm using ka24e MAF.

Best of luck!

Here is a video of what mine was doing.

http://www.youtube.com/watch?v=1t7fwfrwep0
Modified by trevr at 7:58 PM 8/26/2007

[ca18det240hatch]

yah, this one purrs like a kitten at idle....as long as the maf is unplugged....as soon as you plug it in, it idles like crap, and doesnt rev out.....i can pretty much eliminate boost leak unless i have a major one at the manifold. Like i said in teh post, were running a pipe directly from the outlet of the turbo to the throttle body (with the IAC pipe run to it, i know, you need it)

were going to try another igniter just to be funny, and maybe a different dropping resistor, as he had to wire in a 1st gen dsm one. Dropping resistor maybe problem? Dunno, gonna play elimination.

[syphrus]

Yeah, check air fuel problems, also make sure your not 180 out.... Make sure your at the mark for tdc on the crank, and your first piston is tdc. You probobly already know, but just in case.. Good luck!

[progman]

Yeah, check air fuel problems, also make sure your not 180 out.... Make sure your at the mark for tdc on the crank, and your first piston is tdc. You probobly already know, but just in case.. Good luck!

A car can run 180 out??? Wouldn't the exhaust values be open when the piston is on the intake stroke?

[ca18det240hatch]

Nop, not out im pretty sure, i put it to the second mark from the left on the crank pulley...that should be 0 degrees cyl 1 corect? After i set that, i looked at the matchmarks on the cams and the backplate, they were 2 teeth out, so i got sneaky, and fixed it, now when crank is second mark from the left, the two marks on teh cams mark up with teh marks on the back plate.

still runs like *** tho, seems a bit more sluggish.

[syphrus]

Dunno, i guess even in theory the car wouldnt start at 180 out, but ive heard of cars running like this, i just get the tdc mark on the crank, and shine a light in the first cyl, with the plug out, make sure its tdc. ive never had it at 180 out, but ive heard it will run just backfire like crazy.. and barely run at all, this also came from a v8 guy, so i dont know if that makes a difference?

[PapaSmurf2k3]

If the car is 180 out it would be backfiring like crazy, shooting flames through the throttle body, etc. It would probably not be able to rev to 4000 RPMS and probably wouldn't be able to hold an idle either.