my first post, but, ca18det keeps cracking spark plugs and other issues

[ultra apostle]

hello to all. My name is brandon. I have been lurking on this forum for quite a while, and after a lot of research, I have decided to go with a ca18det.After the swap, and some maf issues, I got the car to run half way decent but would sputter terrible under boost. That was with an ecu tuned for 12 psi, bigger injectors, and n62 maf. After fixing that and getting an n60 maf, I socketed my other ecu, and burned an eprom for that particular maf. Now the car will crank and spin over, but if I hold down the accelerator, it will actually try to catch, like spinning really fast, but not fast enough to actually idle. And the main problem is the whole time, since actually getting the swap done, the plugs seem to crack at random. Sorry for the long post, but I am just about at wits end with this thing, I am tempted to drag this old car across the scale and pick up another hobby, like knitting or something.thanks

[themadscientist]

cracking plugs is detonation. I would hate to see the tops of your pistons.

[Buddyworm]

Methinks, it's your K constant. It's not right for MAF. Sounds like it's running rich if it'll attempt to catch when you press the accelerator. Generally you wanna adjust those things when you've got a wideband 02 handy.

Did you also input the VQ table for the new MAF when you made the .bin?

When you're doing the calculation for the MAF conversion what value do you use for the CA unit? 190? I read somewhere that it's actually closer to 240. Try that, see if she'll go.

It's tough to get your K-constant right without a WBO2, especially if you're tuning the K for both the maf and an injector change. Latency could also be an issue. Ideally you'd wanna do one at a time, get it to run, then fine tune it with the wideband.

As to the pinging, as TMS mentioned, back off on the boost. Assuming you're running the stock turbo, 12psi is a little much for the wimpy *** T25.

[ultra apostle]

My k constant is 012a, and this is ecu is a different one than the one I had tuned for 12 psi. I have not changed the boost on my new ecu. I did use 190 when I was trying to figure out the proper k constant though. I will get a wb02 and see what happens after I get off of work.Thanks for helping guys. I am totally a newb at this tuning stuff.Thanks for your patience and knowledge.

[ultra apostle]

while on my lunch break, I checked my tune, and my latency is 37 hex, and I do have the vq map switched to rb20det. I figured that was good, since I have the n60 maf. Also, I only have to change latency if I upgrade injectors right? The only mods I have is a fmic and that maf, and thats only because my swap did not come with one.

[Buddyworm]

Ok good, and you are correct, you don't need to bother with latency unless you've upgraded your injectors.

My calculations for your MAF give me K = dec 228 (hex E4)

That's using 240 to convert from the original MAF. And you've got the appropriate VQ table as well.

Try that, see if the car will run.

[ultra apostle]

Thanks buddy worm. I just tried that, and it still just spins over, but while holding the accel. it will run but barely for maybe 3 seconds like, its flooding out then it dies. I can smell the gas really good, and the exhaust smells strong like fuel too.

[Buddyworm]

Pull the codes from the ECU. See what it's tellin ya.

[boost_boy]

Some advice: While there's nothing wrong with wanting to learn to tune your own ecu, you should practice on a running car and a spare ecu before you/you guys end up making a mess of things. Over-fueling is nothing cool and your car not running will only lead to more posts like this one. While we are here to help, not everyone is on the level of trying tune their ecu themselves. Most people here are just trying to get their cars to run and/or run correctly. Since you're getting some help with this, make sure you keep your thread updated with results as to help others that may try to venture down the avenue you're going. Good luck with your car and take some of the advice given as it will help you along during your journey.

Dee

[ultra apostle]

Thanks boost boy I totally see what you are saying. I kept my little girl last night and today, so I have not had much time with the car other than checking codes As buddyworm suggested. Right now, I have no codes in the ecu. I have also rechecked the timing and its still good. I will check the fuel pressure regulator. The spark plugs are coming out soaking wet with fuel.The weird thing about it is the ecm I got with the swap was already socketed and was tuned for stuff I did not have, like bigger injectors, and a bigger turbo. I found this out later on though The car ran with this tune, just hard to crank and would terribly misfire under boost, basically undriveable. I have a totally stock ecm I switched out, and the car would run good for like 30 seconds, or until I pressed the accelerator(Im guessing that was because of my n60 maf)I was trying to get my car running good so I tried just tuning for what I had at the time.I think I will start from square one, and buy a stock ca maf to go with my stock ecu and go from there.Anybody have one they want to sell? Or trade for an n60 maf? I have plenty of those things....sorry for the long post.

[turbo-sil40]

why dont you just put everything back to completely stock from inj. to ecu and get the car to run perfectly and then modify it so that you will know everything is working correctly before you decide to modify. that is the advice that the master tech at the nissan dealership that I work for said and he has about 20 years of experience plus numerous projects such as vq35de supercharged in s13, twin turbo 350z, turbo ka, built my ca, rb20det swap in s14, all done with no help from outside shop. thats the best thing to do.

[ultra apostle]

I know its been a while, but I made a lot of progress on my 240.I finally found a stock maf and paired it with my stock ecu. The car would crank on the first try, but would not rev past 2000 rpm. After I tested my power wire going to the maf, and seeing 12 volts, I tested the ground side and it was getting 12 volts too! That particular wire is broken somewhere in the harness Im thinking, but after I ran the negative wire to the chassis(ground) the car cranks and runs perfectly.

[r34 gtr]

Good to hear man! Another AL CA18 up and running.

[biosehnsucht]

I'd try to get a fresh MAF wire if I were you, no telling how screwed up that is

[ultra apostle]

yeah, since im off tomorrow I may fool with it. Honestly though, I am just tired of working on cars right now. I had to change spark plugs out on my 200sx, it has eight, and the intake side is a pain! r34, If you ever come down to Mobile, give me a shout!