S13 ca18det will stumble and misfire when warm engine

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Trimmer19
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Joined: Mon Jul 16, 2018 6:59 pm
Car: Nissan 240sx s13 300bhp gangster

S13 ca18det will stumble and misfire when warm engine

Postby Trimmer19 » Sat May 11, 2019 10:16 pm

Hi well the problem now is, starts up fine.
- once warm, normal cruising if I let go off throttle andreapply will jerk. Like it's misfiring if slowly applying throttle/cruising. If I give it gas and let revs go up it will pick up boost and drive fine. BUT Only under load. Yet, when warm starts to run rough like it's misfiring.

- checked plugs weak spark. But fires ok.Moved coil igniter about and revs drop low drastically if igniter pulled back a bit and let go revs are back to normal???

- boosts ok but runs rough when warm it's ok cold.
Temp sensor resistance seems fine.

Of course consumes more fuel now. Starts fine cold though or warm. Just very rough driving when warm touch throttle to cruise and misses quite bad almost as if its surging?

Could it be a case of needing colder plugs??? Ecu code 55 btw.

Thanks team appreciate the help...


Trimmer19
Posts: 10
Joined: Mon Jul 16, 2018 6:59 pm
Car: Nissan 240sx s13 300bhp gangster

Re: S13 ca18det will stumble and misfire when warm engine

Postby Trimmer19 » Sat May 11, 2019 10:18 pm

Trimmer19 wrote:
Sat May 11, 2019 10:16 pm
Hi well the problem now is, starts up fine.
- once warm, normal cruising if I let go off throttle andreapply will jerk. Like it's misfiring if slowly applying throttle/cruising. If I give it gas and let revs go up it will pick up boost and drive fine. BUT Only under load. Yet, when warm starts to run rough like it's misfiring.

- checked plugs weak spark. But fires ok.Moved coil igniter about and revs drop low drastically if igniter pulled back a bit and let go revs are back to normal???

- boosts ok but runs rough when warm it's ok cold.
Temp sensor resistance seems fine.

Of course consumes more fuel now. Starts fine cold though or warm. Just very rough driving when warm touch throttle to cruise and misses quite bad almost as if its surging?

Could it be a case of needing colder plugs??? Ecu code 55 btw.

Thanks team appreciate the help...

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NukeKS14
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Car: 1995 240SX SE - KA24DE-T
2014 Camaro SS 1LE

Re: S13 ca18det will stumble and misfire when warm engine

Postby NukeKS14 » Sun May 12, 2019 7:03 am

Do you have a wideband? 55 is no fault detected by ecu. Sounds like it's running rich.

What do you mean by "resistance seems fine" on the CTS? Did you pull it out and perform the actual test to validate it or just Ohm it out with a DMM in the car? If you did the latter, you can't call it definitively good. Single point resistance check won't tell you whether it's responding along the temp/resistance curve like it should.

Have you done a boost leak test?

In the factory service manual, EF&EC page 125 has your procedure for testing the ignitor, if boost leak test doesn't yield anything I'd do that next.

Trimmer19
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Joined: Mon Jul 16, 2018 6:59 pm
Car: Nissan 240sx s13 300bhp gangster

Re: S13 ca18det will stumble and misfire when warm engine

Postby Trimmer19 » Mon Jun 24, 2019 4:39 pm

Thanks for this reply Nike haven't got wideband, but installed a new boost controller today.. revs mazes out at around 55000 whilst boosting.

Problem I've got is took off the air pipe that connects to rocker cover from the air filter pipe and revs drop if put back on revs are up to 1400 on idle

Revs increase as temp goes up🤔
When it's warm it misfires pretty bad, id let go of throttle and reapply it's not smooth it's very rough driving unless I put my foot down it runs smooth but steady cruisin really bad misfires...

Checked coils by pulling an off 1 by 1 changed plugs??? Pretty lost now. Really appreciate the help thanks

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MeanGreenS13
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Re: S13 ca18det will stumble and misfire when warm engine

Postby MeanGreenS13 » Tue Jun 25, 2019 4:48 am

Moved to CA18DE/CA18DET Forum Section. There are a ton of very knowledgeable CA18 guys there and may be able to help you quicker.

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float_6969
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Re: S13 ca18det will stumble and misfire when warm engine

Postby float_6969 » Tue Jun 25, 2019 7:02 am

If you're moving electrical components around and the engine behavior changes, you probably have a grounding issue. Remove all of the grounds, clean, and re-tighten. If that doesn't change anything, then post of a list of your modifications. That will help me to try and figure out what might be causing the issue.

Trimmer19
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Joined: Mon Jul 16, 2018 6:59 pm
Car: Nissan 240sx s13 300bhp gangster

Re: S13 ca18det will stumble and misfire when warm engine

Postby Trimmer19 » Fri Jun 28, 2019 1:23 pm

Thanks float,
Sorted igniter took off wires and reconnected etc that's working ok now. Just reinstalled the ecu and took got drive still misfiring bad when cars warm only on cruise though if I give it throttle itll pick up and no misfire but tharvmeans boosting and driving on high revs..

Here's the mods,
Stage 2 turbo noz ecu
370cc injectors I say this coz they're just grey white colour heads I believe 444s wouldve been yellow. But maybe because they're same code as 444s a404 so not too sure.
Gt2871r Turbo
R33 intercooler
3pin maf
3 inch exhaust straight through

One thing is though float it's never ran o2 sensor sincecive bought it, because wires were broken off the sensor and previous owner never bothered. I've now got another o2 sensor been looking at wiring but couldn't locate the 3 wires needed to connect o2. You probably know more about this where would I find the o2 wires? I know they've been broken off the o2 but need to find em in the wire loom.. searched the fsm but publication of these wires apart from connector.

Could it be that there's no o2 connected so it runs fine cold but when temp rises as car gets warm and starts misfiring pretty bad like stuttering on cruise, hard acceleration take foot off and give it gas itll be very rough jerky whilst reapplying throttle, bad has mileage btw???

Also if I take off the air pipe connected to rockerhose pipes coming off the air filter trunk that goes straight to rocker cover pipe itll reg a bit low soon as that's connected revs are raised..
Thanks float really appreciate the help.

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float_6969
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Re: S13 ca18det will stumble and misfire when warm engine

Postby float_6969 » Mon Jul 01, 2019 4:06 am

The engine should run fine with no O2 sensor, you'll just have crappy fuel economy.

Try turning the engine off, unplugging the MAFS, and see how it acts.

Trimmer19
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Car: Nissan 240sx s13 300bhp gangster

Re: S13 ca18det will stumble and misfire when warm engine

Postby Trimmer19 » Tue Jul 02, 2019 6:05 pm

Doesn't seen to be maf got a clue though, if I turn idle conttol valve all the way down meaning no air at all it still idles pretty high and as temp moves idle also goes up. But if I open idle control nut 10mm to increase idle, idle will increase. So this could mean a problem with the idle air control not making any difference when its completely closed but makes a difference if opened??? Ever had a problem like this? Maybe the gaskets leaking 🤔

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float_6969
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Re: S13 ca18det will stumble and misfire when warm engine

Postby float_6969 » Thu Jul 11, 2019 6:12 am

What about the fast idle valve, under the throttle body? They're terrible about sticking and doing dumb stuff. It feeds air in right behind the throttle body, on the engine side. Try removing that line from the manifold and capping it on the manifold side and see what happens.

Trimmer19
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Joined: Mon Jul 16, 2018 6:59 pm
Car: Nissan 240sx s13 300bhp gangster

Re: S13 ca18det will stumble and misfire when warm engine

Postby Trimmer19 » Fri Jul 12, 2019 10:54 am

Are you referring to this pipe that comes off the intercooler t piece off cold air reg that goes straight to iacv behind throttle body, can't attach photo for some reason?
I've got a slightly larger pipe coming off intercooler that goes in here, then t piece, then 1 too cold air reg and 1 straight to iacv. If i pinch the 1 off intercooler then revs drop.. possibly that pipe may be too big but then it's a bigger intercooler.

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float_6969
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Re: S13 ca18det will stumble and misfire when warm engine

Postby float_6969 » Tue Jul 16, 2019 8:37 am

We can't host pictures here, you'll have to upload it somewhere and link it.

Yes, there should be one hose that comes off the cold pipe, goes to a Tee, with one side of the Tee going to the AAR (Aux. Air Regulator) that's located right under the throttle body, behind the upper radiator hose. It looks similar to this;

Image

The the other side should end up feeding the idle control assembly on the side of the intake manifold. It contains the IACV and the FICD.

Image

If you're pinching the hose before the Tee and the idle drops, then one of the 3 idle control valves that Nissan used on this engine is stuck open. Try pinching the hose shut that goes to the air regulator, which is the valve under the throttle body, behind the upper radiator hose. It's very common for them to get stuck open and cause problems.


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