CA18DEt Experts please help!!

[MrAlex]

Hello ,

ive been around this website just looking really never post , but i can't seem to figure out my problem and im tired of doing one thing over another . i have search many forums and gone over everything over and over again ,

here is what my problem is :

on cold start my car hesitates to start and usually , have to rev it up at least once or twice for the motor to idle by its self , put after that it peers like a kitten , and will not have that problem after warm .my other issue is that my car will not boost past 2-3 pounds at all specially will not go anywhere in full throttle , it wont sputter or stumble , just feels like it hit a power block, but if i let of the throttle a little and let boost drop below 2-3 pounds its fine . accelerates just fine also and will rev past 6k no problem unless i go full throttle .

when not under load i can rev the motor to about 5k , and it stops by its self and sounds like i have a msd 2 step , but if i let of the gas a little and let boost build just a slit then i can rev past 5k under no load .

My Set up , is all stock not after market parts other then a sard blow off valve that is not recirculating .and a walbro 255 with a fpg . and a z32 filter .

What i have replace is , Tps , coils, spark plugs , CAS , pvc valve , timing belt water pump .

no codes on ecu at all , i have code 55 .my knock sensor is hook up with a 1m ohm because i had an issue with it , but acted way better when i did the 1 ohm thing to ground .

i can see my waste gate move , slightly when not under load , ( i can't see it when driving the car) .turbo has no shaft play what so ever and you can hear it spin nicely , all my vacuum lines are hook up and my second butter flie work just fine . they open (move) then you apply throttle .

my car has no over heating issues , and im running stock inter cooler and piping , i feels and hear no leaks when not in load , if i apply full throttle when in load is sound like the noise your car did with an intake , it whistle lol if you know what i mean.

i have also taken the blow off valve off and ran it with out , has no change to the motor at all , and run no cat

other then that i dont hear any noise,

i know its lots of info and i might have some miss spelling i there , but im only asking for help please dont try and burn me with stupid comments ..

thank you all for your help in advance

please help if you have ran in to a problem like this before

O

[meminto]

Two things to check..

The first one is the wastegate, sounds like the diaphram or spring is shagged to display the moving symptom...

Second, if it has a catalytic converter, take it off the exhust and check that it hasn't collapsed..

Hope this helps..

Although there are others here more experienced than myself, wait for a couple of answers before rushing too it
Modified by meminto at 1:06 AM 3/12/2010

[MrAlex]

OKAY UP DATE , SO THINKING IT WAS THE WASTEGATE PROBLEM I SWITCH MY HOLE TURBO TO A SR 25T , A LITTLE BIGGER AND A DIFFERENT WASTE GATE , CAR STILL RUNS THE SAME

ALSO NO CAT , STRAIGHT PIPE

[float_6969]

Cold start issue's are due to the cold start valve located under the throttle body. Part number is located in the FAQ.

Are you 100% sure you don't have ANY leaks in the intake system anywhere? If so, what MAFS are you using? Have you checked the ignitor? The process for checking it is in the FSM .

[MrAlex]

I HAVE GONE OVER IT ALL , I SEE NO SIGNS OF LEAKS OR CRACKS , I HAVE A NEW IGNITOR , AND STOCK CA18DET MAF, AND NO CODES

[ca18detgabby]

I remember Dee talking about making no power because the walbro over powered his stock FPR and killed it.

I would be very cautious of any USED wastegate. It is how many years old now? at the very best it is 12 years old........

beyond that I would be checking the exhaust gasket and verifying that the gauge itself is accurate.

[MrAlex]

Well I have an adjustable fuel pressure regulator , also my waste gate is new as well as the turbo and new exhuast gaskets , plus I know the wastegate is working for sure because it won't build past 2-3 lbs and well I sure feels like it doesn't .

Please more ideas

[r34 gtr]

Hate to ask, but the waste gate doesn't have a 3psi spring in it, does it? I remember having that happen to me once, and boy did I feel dumb. Worst part was that it took me months to finally figure it out.

If you pull the line off the waste gate, does it make more boost? It should. If it doesn't, I would check the ignition coils, the intake tract for leaks, check for vacuum leaks everywhere, my ignition timing (fo sho!), and possibly add a few ground straps for good measure.

If none of that fixed it, I would probably break down and cry. Once I was done crying, I would buy a 1991 Toyota Tercel and get out of the modifying cars business.

[bentvalves]

its obvious you have a knock sensor circuitry issue.

I say this because you mentioned having added 1 ohm to ground or something or other to the knock sensor circuit and the problem getting better but not going away.

reading comprehension pwns everyone, except the OG poster

[r34 gtr]

Ah, well then.

Greg you know I don't read.

[bentvalves]

its like you guys are on autopilot or something, which equates to -

boost leak

vac leak

bad MAF

did you unplug MAF and see what it does

timing is out, no not that timing mechanical timing

and the list goes on

[MrAlex]

I DID HAVE A KNOCK SENSOR PROBLEM , BUT THAT HAS GONE AWAY AND CODE HAS NOT CAME BACK , AFTER PROBLEM FIX ,

THE WASTE GATE IS A STOCK SR20DET WASTE GATE SO I DONT THINK ITS A 3 LBS SPRING , UNLESS NISSAN HAS A 3LB WASTE GATE FOR THE SR . I HAVE RAN THE WASTE GATE WITH OUT A VACUUM LINE AND NO IT WILL NOT MAKE MORE BOOST ,

COILS AND IGNITION COIL ARE NEW NO VACUUM LEAK CAR , IDEALS FINE IF THAT HELPS , TIMEING IS ON THE MONEY CHECK IT 5 TIMES ALREADY I HAVENT ADD ANY EXTRA GROUND WIRE , BUT I THINK ILL BE DOING THAT TONIGHT WONT HURT .I HAVE UNPLUG THE MAF AND CAR WILL RUN LIKE SH%& IF UNPLUG , + MOTOR REV PAST THE 2K MARK , SO I KNOW ITS ATLEAST WORKING ..

I HAVE ON AN IDEA ON HOW TO CREATE BOOST AND SEE IF I CAN HEAR ANY LEAKS , ILL BE DOING THAT TONIGHT FOR SURE ..

PLEASE ANY OTHER INFO WOULD REALLY HELP ....

[bentvalves]

I STILL THINK IT HAS TO DO WITH YOUR KNOCK SENSOR BECAUSE WHERE DID YOU HEAR OF THIS OHM TO GROUND MOD, I HAVE NEVER HEARD OF ANYTHING LIKE THIS BEFORE AND IT SOUNDS LIKE A BANDAID. AS FOR NO CODE NOW, I DONT KNOW WHAT TO SAY, MAYBE THE OHM TO GROUND IS TRICKING THE ECU INTO THINKING ITS FINE?

ISNT IT PAINFUL READING THIS, ITS ALMOST LIKE I AM SCREAMING AT YOU RIGHT?

[r34 gtr]

Greg you are such a d!ck. Helpful and insightful, but still a d!ck.

OP, do what ks13 says, he knows.

P.s. I will be in NH this summer for sure. I just took a job there. Should be there from July-September. I will be bringing the YZ50 Death Machine (that I got from PapiChulo on here) so shenanigans will be had.

[sjbsuperman1425]

I STILL THINK IT HAS TO DO WITH YOUR KNOCK SENSOR BECAUSE WHERE DID YOU HEAR OF THIS OHM TO GROUND MOD, I HAVE NEVER HEARD OF ANYTHING LIKE THIS BEFORE AND IT SOUNDS LIKE A BANDAID. AS FOR NO CODE NOW, I DONT KNOW WHAT TO SAY, MAYBE THE OHM TO GROUND IS TRICKING THE ECU INTO THINKING ITS FINE?

ISNT IT PAINFUL READING THIS, ITS ALMOST LIKE I AM SCREAMING AT YOU RIGHT?

I was thinking the same thing, both on the knock sensor, and the CAPS

[MrAlex]

I was thinking the same thing, both on the knock sensor, and the CAPS

I will be rewiring my knock sensor tonight , to see if that changes anything , but i have seen many write ups on how to by pass the knock sensor .

also im sorry about the caps , i use caps at work all day and forget to take them off when not useing it at work ... sorry that is such a big problem for everyone , didn't think such a little thing would bother people ... thank you

[r34 gtr]

Don't sweat it man, it can just be hard to read when someone types all in caps. Having to type in caps at work is a completely legitimate excuse. Some people do it just to be annoying, the jerks!

[MrAlex]

rewire my knock sensor , and still same problem

[r34 gtr]

Well s***...

[ca18detgabby]

I still think the adjustable FPR is bad. how do you know what pressure the FPR is set at?

PS what ECU are you using?

[MrAlex]

I have a gauge set at 37 psi and I have a stock ecu , I have also already swap ecu and have not seen a change at all

[busteds13]

I know it might sound uppity, but, might your fuel system be having problems, it sounds like it might be blowing out spark at boost? mebbe you should double check your spark gap? mabey your dropping resistor is slowly pooping itself under load and your injectors are oversaturating?Mebbe its as simple as the quality of your gasoline, you might need to run like 94 and some injector cleaner. those grounding straps might fix it.then again i havent found a solution either my car wont run good in boost till shes warm, like refuses, completley to boost around 3000 rpm. but once warm the throttle evens out and is all sortsa sexy.

recentley while looking for a new ignitor i came across an old thread in which dee mentioned something about something solid state pooping itself and such and lots people trying to pass off bad parts as good.... for redundancy's sake, and also your own peace of mind, mebbe you wanna run all the rudimentary electrical checks on all systems associated with the suspect parts. if theyre good you will know for sure, and when they do indevitably die youll know xactly where to look. and if theyre no good then mebbe ittl fix your issue.

Come to think of it my TPS plug came off abit and acted all weird intermiddently, and the ECU refused to pick it up, proly couse it sorta got a signal somehow. i figured that one out by wiggling harness plugs for a bit.

I know these sorts of issues can be a b1tch but its totally worth it.

[MrAlex]

blowing out spark at boost? please explain ? also , all my harness plugs are plug in fine nothing lose , on quality of gas - well we dont have 94 in california best we get is 91 also i have change out my plugs not because my old ones where bad but because there cheap and i might as well done it to see if that might of been a problem and they are gap to 1.1 mm like the fsm said .and my car wont boost even if warm ..

today i will start testing everything again with a ohm reader ,

does anyone know how to test the o2 sensor ( i have no code for it but want to test it )i have read the fsm but dont understand the part where it said the ecu should blink 9 times in 10 sec , and that it must be in mode I or II and rev at 2k rpms , but if i have my car on and i try to put it in mode I or II it does nothing ?

can someone explain this test ?

[busteds13]

Im sorry i got in to a long winded disertation and forgot to mention the O2 sensor, when i first put my swap in i spent about a week ripping my hair out cause sher wouldent start or stay running, bought a new O2 sensor and its all good, they get clogged, and they burn out and such, and they're under 60$

I would suggest testing the hardware, like the O2 sensor itself for proper resistance 12V signal ect. as it says in the manual, and if that checks out then try the self diagnostic mode. I only use that for mode III but thats cause the other ones confuse me.

also you might wanna try resseting your ECU as you go about making changes, cause itll still think sensors are missing, or hasent corrected itself, our ECU is basically playing pong in there, its old. then again you might be doing this allready.

oh, and by blowing out spark at boost i was thinking, that your gap was too big, and you didnt get enough boom cause the compressed air coming in is too much for the spark.

it sounds like youre bogging or leaning out at one point, and the engine corrects for itself, there was a thread recentley that mentioned the diffrence between EDM and JDM CA's and setting timing to either 15 or 10 degrees BDTC. but i dont remember exactly. Dee or TMS would know, mebbe even Gabby.sometimes the CA idles sexy, but stumbles all over itself in boost, for siplicitys sake, i vote for the O2 sensor.

[busteds13]

i just re-read your OP and that wistling noise sounds like a boost leak, sometimes the silicone couplings will develop a crack, that looks like its not there, but under boost in load opens up and leaks, but you dont notice it cause it doesent look like it exists. that happened to me one cold winter night and i had to get a tow home, at like 3AM, still buzzed, and was angry at myself later on when i wiggled all my Silicone connections and dicovered the crack in a coupling. xspecially cause youre running a stock IC. easiest way to check that is ghetto-rig a straight pipe from turbo to trottle body, and if it runs good then you know where your issue is.otherwise you would prolly wanna build a boost leack tester.Good luck

[MrAlex]

i know my o2 sensor does work , it new for one ,another i dont have a code for it in mode III and mode I and II is to test the O2. so that why im truying to figure out how to test the o2 via ecu.

also i have check all piping , and have pressure tested everything, the noise was coming from my throttle body ,sounds like its coming from the butterfly , i can't feel any air .. just a little from the shaft , but im sure thats normal ,and yes i have already done that and by past the intercooler and all piping , and still same result , no change

and i clear my ecu , when ever i replace any sensor

and my timing is set at 15 bdtc

[ca18detgabby]

IIRC it was the EDM was set to 5BTDC or 0....... I cant remember, not the JDM 15BTDC.

where exactly are you leaking?

back in the day I remember tim had issues w/ one of this butterfly valves stucking open and making all kinds of issues. maybe tim would chime in...

[MrAlex]

How could I know if my motor set is edm or jdm ?

[ca18detgabby]

it was discussed and Idk if anyone for sure confirmed this.

JDM vs EDM

8port head vs 4port head

there is other stuff, but that is very basic level.

[r34 gtr]

No no no,

Euro 4 port CA18DET used 15deg BTDC base timing, and

JDM 8 port CA18DET used 10deg BTDC base timing.

I always had my JDM CA at the 15deg Euro timing, and I never noticed a problem.

You see, the only FSM we have in English is one from the UK that, subsequently, everyone uses because it is written in English. So everyone (me included) sets the base timing wrong and so on and so forth.

So try resetting base timing to 10deg, and see what it does for you. No guarantees though.
Modified by r34 gtr at 10:35 PM 3/27/2010