Let's play who's smart, and who's not...

Canada Nissan Automotive
1

here’s a trouvleshooting question for everbody with a brain, if you dont have one, please dont bother trying…

having a real problem getting a friends ca18det to run properly

symptoms

at about 4k, right when the motor is just getting under load (it revs freely, as long as there is no load) it has a sputter, and backfire, like a cylinder or numerous are not getting air fuel or spark, basically at 4k, a dead cylinder comes up

Ecu is throwing code 13, but that is not enough to do this. (eng temp code)

No boost leaks (unless the IC core is fucked)

Injectors. cas, coil packs, ignitor, and a few other parts have been changed out to nulify possible causes.

here’s my thinking…

I am beginning to think maybe the fuel filter is clogged??? cause every time the fuel system had the pressure releived, the car ran good after for a couple minutes.

and more to point at the fuel filter, it does not rev fast like other ca’s I have driven and worked on. It just has slow and gradual acceleration.

I have my doubt’s about it being the maf, I know it’s not a mechanical issure either.

ANy body ever had the same issue?? And anyone ever had a clogged fuel filter?? symptoms???

this is the mods to the engine
mines ecu, fmic, 440cc and 370cc injectors (we have tried both), 300zx tt fuel pump, ka24de fpr (I know it has like 3psi differece between stock ca one) hks exhasut, t28 (newer garrett unit, directly from garrett) seconday buterflies have been eliminated and removed, intake mani, and sec. mani have been ported, and I think thats aboiut it’

here’s the weird thing

when this problem first occurde, I changed the injectors out, and it ran perfect for about ten minutes.

I recently did the head gasket and a full gasket kit/timming belt for him, and when it was in the car it had about 1/2 hour idle time, and ten minutes of bagging (hard), then they were doing a brake stand, the car has a very minor stumble and they came back to the shop, and we found and Ic pipe had cameloose, fixed the ic pipe, and guess what the same stumble issue is now back.

so the only thing consistent to me is that both times it ran good was after the fule system had all pressure releived. maybe the filter has some matter in it???

give me some help guys.

peace
jason

I’m tired, hopefully this makes sense

and another one, found 2 sources listing different head stud torque specs for the ca18det, does anyone have an FSM?? I need to prove somebody wrong… he says 80 pounds… I dont think sooo… bu need a outside thrid party for him to beleive me anyway./

2

Check the spark plugs. My guess is that they are gapped to far, causing the car to misfire once boost hits.

3

What condition are your spark plugs in right now?

A vaccuum leak would not do this so narrow that one out.

How’s your fuel mileage? Regular or really low?

4

http://www.n-e-c-c.com/forum/viewtopic.php?t=4464

5

I’m also voting spark plugs… my CRX was doing pretty much the same thing (cept for that whole Boost thing), and changing the spark plugs and gapping them properly fixed it.

6

Coolant sensor could do it, it would change the mixture, My car was stumbling and surging and I took the MAF out, cleaned the elements, and it ran smooth after that. Plugs could be fouled too if its running rich, I’dd try cleaning the MAF, and changing and gapping the plugs to proper gap. 0.8mm or like 0.024" - 0.032".

On another note, how did you find out the code it was throwing, did you hook it up to a reader or is there a way to get the car to tell you w/o one?

7

re-gap the plugs to .028, get a new fuel filter(cheap and easy) then reset the ECU

You have tried everything else i can think of too…

8

I’m not very familiar with the ca18det but does it have twin coils like my ca18et? If so then I would check your primary coil seeing as it shuts down at around 4k. My car pulled the same trick, sputtering and coughing at around 3500-4000 under load. If it only runs one coil I can think of two other things to check. 1: check you fuel pump operation. no concrete reason but this seems to me like a fuel problem. That and if your pump is weak it will couse the desribed symptoms. 2: Seeing as you have replaced injectors and some other things check all you connections to assure they are snug and clean. I had an injector plug work loose and it did the same thing to my car. Ran fine until I put the boot to it past 3k, the coughing and farting. What messed me up wa the fact it was only loose so the misfire only occured under load.

Oh and I re-read your first post about replacing the coil packs so check the wiring to the coils if you are sure both coils are good. A loose or corroded wire to your primary coil could be giving you grief. Hope that helps.

Oh and it could possibly be an intermittent boost leak. I had a boost leak the only happened over 5psi. At idle it didn’t even become a vacuum leak. I removed and resealed all my charge pipes and the problem went away. (man my car has had a lot of problems huh?)

9

well guys thanks for all the advise but it was as easy as changing the fuel pump. Solved the problem…at least it seems to be gone for the moment :shrug:

10

im the dumb guy who decided to type even tho you asked him not to… I think that makes me team captian for the stoopidz… haha sorry i dont have any idea whats wrong with his car…

11

you have a probably sensor problem, replace your coolant temp sensor…

12

My car did that when the flux capacitor fell out back in '67 or was that in 2045? 8)

13

Probably because you couldn’t convert mph to kph :lol: 88 what now?