s13 ca18det idle and driving engine problem

[pktheo]

Hi All

Im new to this forum and i have spend days looking for advice on what could be causing the problems on my car.

When its hot the idle varies by about +-80rpm and it makes a popping noise from the exhaust, the engine is also shaking quite a bit i'd say about 1cm of movement you can feel it from inside the car whilst driving it hesitates at 2500 and 3500 just before boost, i'll give you as much info as possible.

I bought the car in feb 2011 with 223000kms on the clock it had had a full rebuild at 200k and in april 2011 wrote off the front end (only stuctural engine wasnt touched) in an accident, rebuilt the front end, and made the folling modifications, fmic, t28bb from s14, alu rad, hks back box with 2.25" straight through system, ported ecu with stage 2 chip, added gauges and a few other bits, once she was back on the road again had no problems apart from the turbo over boosting but then this problem started so i changed the plugs for ngk iridium hr7 and still the problem persists, i thought it might have been the ecu so i reverted to the original one that came with the car and all was well but as soon as the car was hot started the same thing again.

I dont know if the timings out or the mixture is wrong or if its something maybe more?

if anyone can help me it would be greatly appreciated.

Many thanks

Theo

[Hashiriya415]

If you can plug in scan tool and check to see what coolant temp your ecu is reading. If not then check fsm how to manually test coolant temp sensor and wiring from sens to ecu.
Check coils for damage, burnt surface/cracks/ etc..
Look at spark plugs, sounds like your running rich and see if all 4 are wet or just 1...
Fuel pressure check...
There is more to it, these are just some basic tests you should do.

[pktheo]

Hi, thanks for the swift reply, I will be able to plug in to a computer in a few days, Coolant is reading about 1mm about half way on dash and she's running normal oil temp, just replaces plugs about 5 days ago, if she's running rich how can I adjust the mix and by how much do you think?

Many thanks
Theo

Sent from my HTC Desire HD A9191 using Tapatalk

[smokescreen240]

use an safc and an aftermarket fpr

[pktheo]

I have a fpr installed but I don't have an safc or the budget to buy one right now is there any other way of doing it?

Thanks again
Theo

Sent from my HTC Desire HD A9191 using Tapatalk

[Hashiriya415]

You haven't heard what I said. Check your ECU'S READING. Not your gauge.
I don't care if you replaced your plugs 5 minutes ago. Check and see what they are now. Google "how to read spark plug". You will find 100's of pics and description to each one.
And absolutely do not start changing your air fuel mixture. First get your engine running right then tune after that.

[pktheo]

Sorry I misunderstood you, my friend has a computer he should be able to plug in to get the reading but it won't be for a few days yet I'll check plugs at the same time and report back, thanks again for the advice
Theo

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[g35gabby]

Sounds like you have a vac leak.

The CA isn't something you can plug in and read, it is not that advance of a ECU(OBD0). you can set the ECU into code mode and watch the flashing lights to monitor for fault codes.(sometimes you get lucky, but it rarely worked for me)

I would be doing a boost leak test, followed by checking my CAS and make sure it isn't pulling timing. The usual suspects state side are harness issues and vac issues, but being an OEM harness it shouldn't be a problem.

Ps your tune? it is a dyno rom tune? or just an off the shelf deal?

[pktheo]

Damn I thought I would just be able to connect it, would a boost leak be audible? What should it read at idle? and what's the best way to test for leaks and most common places?

Many thanks
Theo

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[Hashiriya415]

If the car is fine after 3500 then its not a vac leak. From the way you described its just 2500-3500 where it hesitates.

[pktheo]

Yes bang on 2.5k it hesitates then 3.5k then it goes on boost fine, there is another thing it's doing but I don't think it's related, its got a hks evc boost controller and when boost rises to 1.1bar under half throttle the boost cuts and it's like getting hit in the face with a sledgehammer but under full throttle it only does it occasionally and most of the time the controller just cuts the boost like it should.

Thanks
Theo

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[ch1873857]

dead spot in maf.. seen it a lot with cas.. unplug your maf and see if it idles any better at all. the ecu will run in limp mode and wont rev over 2k

[Croustibat]

Yes bang on 2.5k it hesitates then 3.5k then it goes on boost fine, there is another thing it's doing but I don't think it's related, its got a hks evc boost controller and when boost rises to 1.1bar under half throttle the boost cuts and it's like getting hit in the face with a sledgehammer but under full throttle it only does it occasionally and most of the time the controller just cuts the boost like it should.

Thanks
Theo

Sent from my HTC Desire HD A9191 using Tapatalk

Your fuelling system is not up to the job. stock injectors are maxed with a 0.8bar boost on a T28. It means you are running LEAN. Which kills engines.
There also never were T28bb on S14, only on late S14a and early S15, so i guess you have a normal T28.

things to do :
1/ clean the AAC valve
2/ check the CAS splines, or just check your timing. If it does not stay at 15° your CAS / exhaust camshaft driver needs a change.
3/ get proper injectors and proper mapping ... forget about an SAFC, you dont know how to use it anyway.

The "sledgehammer" you are getting is a fuel cut btw... Get the boost down to 0.8bar or get ready to melt something.

[pktheo]

Hi there, yes it is a bb as I researched it online and said from a late s14 I was told the stock injectors will run 1bar so I guess I was told the wrong info I will check the things you said and I hope it works thanks again for everyone's advice :)
Theo

Sent from my HTC Desire HD A9191 using Tapatalk

Sent from my HTC Desire HD A9191 using Tapatalk

[pktheo]

Hey Guys, so sorry for the late reply, i managed to fix it thanks to you and a few other people, the problems turned out to be a cracked rocker cover hose, and the there were two vacuum pipes on the actuator which where the wrong way round, anyways now she drives like a dream.
Thanks again Guys
Theo