at the end of my rope, what the h3ll is wrongggg

[ca18det240hatch]

ok, ive been having mileage/power/hesitation issues for a bit....its never run right since the rebuild....lack of power, sometimes poppy coming onto boost, BAAAD fuel mileage, like 200 km to a tank of fuel...

what ive done to try and fix

Adjustable FPR, set to 38 psi444cc injectors and a rb20 maf, with a tune to suit itwalbro 255 was installed when motor was installed. checked for codes, 55, nothing wrongchecked for boost leaks, tightened all clamps, checked all hoses, theyre fine. Checked timing, 14 degrees btdc, corec? cam marks im pretty sure are dead on, itll rev out, no problem, its just not right, and its verrrrry rich....i need a wideband to verify, but it stiiiinks...but it pulls pretty good, just not like it did before

so....any ideas? WTF WTF WTF. i just dont understand it....compression is fine too, 140 across all 4.....

help

[driftin8ez]

fpr should be set to 36 psi. Im sure it's not going to solve your problems but it could help. Also what is your bov game like? Maybe it's leaking or not holding the boost properly.

[ca18det240hatch]

running an arc PROF bov, to atmosphere, im pretty sure its holding fine. at idle it doesnt open or close ever, and if i rev it up in neutral, i can get 5 psi atleast, so i hold my hand in front of the bov and theres nothing coming out.

[driftin8ez]

How did you check for leaks. Did you make a leak tester or did you just go around and re tighten clamps? To me it sounds like un-metered air is getting in an out somewhere. What about your maf? Do you have another to test for a while to see if maybe it hasn't bit the dust? You didn't list it but i assume you replaced your o2 sensor with a quality ntk unit right?

[ca18det240hatch]

does oxygen sensor have ALOT to do with mileage/running condition on the ca18det?

i dont mean to be stupid, its just that i owned a rx7 turbo II before my ca18 and it's oxygen sensor did diddly Fck all

[driftin8ez]

I would say so. Also get ready for this thread to go south as everyone here chimes in and says they used to have a turbo II.

That car was such a blast!

[ca18det240hatch]

yah i lovvvved mine too, but i just couldnt handle the mileage anymore, and i knew it had a cracked seal....which i disclosed to the buyer naturally.

eh, time for greater things.

so oxygen sensor=very important? is there any way i can test mine?

[driftin8ez]

ya it got pretty expensive with the 10 mpg's and the 2-stroke oil i had to mix in every fill-up. Check the fsm. There is a way to test the o2 sensor through the ecu. I've been having some slight mileage issues myself. I just ordered an ntk sensor off ebay to see if that will help. Also pick up a new water temp sensor. It's like $10 and it cant hurt to have a new one. If that is bad your motor will run way rich, most of the time it wont even throw a code. Wouldn't the 450cc injectors lower your fuel mileage a bit aswell? I wouldn't be looking for more than 300 miles to the tank with those bad boys in. One time i made a 220 miles round trip to look at an s12 i eventually bought on a half tank. I was amazed that i actually made it 110 miles on a 1/4 tank and was confident i could make it back.

[ca18det240hatch]

the injectors shouldnt affect my mileage THAT much off boost i dont think...should it?

[driftin8ez]

ya thats true. Do the o2 sensor test and definitely pick up a coolant temp sensor if you didn't replace it already. That should help. Also back to the maf. Do you have a spare you could test out or possibly give it a good cleaning. I'm sorry i cant just tell you oh it's your flux transcoupler that is out of whack but i'm just trying to tell you some of the things i would check. Do you have a boost leak tester?

[ca18det240hatch]

i had a ca18det maf on it, a ka24e maf on it, and now the rb20 maf, all teh same problems....so i can eliminate maf.

i have a brand new coolant temp sensor for a ka24 in there, pretty sure theyre all the same..

oxygen sensor is definately something i should look at....

im reallllllly leaning towards my microtec now..........i hate working with the cruddy ca18 electronics.

[driftin8ez]

yep the ka24 cts is the same. I do have to tell you. Th eo2 sensor will only help you during closed loop operation.(cruising on the highway) The computer doesn't even look at the o2 sensor at wot. So that might not solve all your problems. You said it's a fresh rebuilt. Is it broken in yet?

[ca18det240hatch]

yes, it is broken in, but i think its coming apart again....my compression SHOULD be 160 psi, but its 140 if that, so thats not very good. I think i effed up on clearancing the rings bigtime. Ah well, atleast i know my bottom end is right, oil pressure is still 70 psi at cruise, 15 psi at idle.

but still, even with 140 psi, i should be able to get HALF decent mileage. this 160~k to a tank is total BS.

i read how to check the oxy sensor, ill check tomoro. it said in mode 2 it should blink on and off more than 9 times in 10 seconds.

[driftin8ez]

yep thats what it is. I remember trying to count to 10 seconds in my head while i put a dot on a piece of paper every time the light blinked... it made my head hurt.

[roplusbee]

You guys always have great information to give. I have negleted checking my sensors, so now this thread has motivated me to just go ahead and get new ones. I have not installed my Z32 MAFS, 550cc injectors (and supporting fuel system mods), and tuned ECU yet, because I am tring to ensure that all is well first. By the way, what is the leak tester that you are talking about? I do all of my work at the Auto Hobby Shop on base (they are very helpful), so I would definitely have to check to see if they have one or purchase one. Thanks

Good luck with the fuel economy hunt. Let us know what did the trick, that is, if you can get better fuel economy out of it.

[boost_boy]

I'm going to comment on this thread, you guys will hear what I say again in another thread that I'm going to make for everyone to read. You want your car to run right, take out the supposedly upgraded computer you got from god knows where, put your stock injectors in, and put your stock AFM back in. You should never put strange engine management combinations on a fresh rebuild because you don't how the computer is going to act. Your ecu is more than likely causing your car to run stupid rich, fouling plugs, rinsing down your cylinder walls with raw fuel which is in turn prematurely wearing out your new rings. Take my advice and change that crap out or you'll continue to whine and be very dissatisfied with your swap until you are forced to scrap and sell it.

Dee