hesitation when cold

[pegliobaglio]

Right chaps wonder if anyone can help?
I took the car out a couple of days ago and all was fine,then yesterday took it out again and was a weird hesitation when the car was warming up,felt like it wasn't engaging the power properly,kinda hard to explain. Felt breathless and juddered a little .
What would you suggest I check first?
Thinking maybe mani gasket ?
Any ideas would be much appreciated

 

[pegliobaglio]

Any ideas guys?
Feels like its holding back/struggling on light throttle around 2.5k rpm gonna check the gaskets tomorrow any other ideas?
Gonna check the plugs too ,don't know how I would go about checking the coilpacks without replacng them which is on the to do list anyways.

 

[S15AK]

yeah I would say its spark related, so either coilpacks and your spark plugs are on the way out. Its quite cheap to replace your plugs so if they are not that new I would start with them.

 

[pegliobaglio]

Cheers mate, I changed my plugs to iridium about dec last year so prob a good bet they could need replacing.Are the iridium the best plugs to go for or does anyone have any better alternatives?

 

[S15_SAM]

Hey peg. I had similar issues on light/partial throttle, it would almost hesitate and stutter. For me it was my AIr flow meter, I bought a second hand one from a chap on here, fitted it 6 months ago and haven't had a problem since. As I didn't change anything else.

Its a common issue on subarus, which I work on and mine had identical symptoms.

I was told S14 ones were the same so if you can find a cheap good 2nd hand one then try it. Or if your brave then clean it with electrical cleaner solvent but I'm not keen on that. Might be worth it to test it.

Also plugs whys then I run NGK bcpr7es copper plugs and change them every 3-5000 miles. I oonly did this as before it was mapped 2 of my iridiums melted and I got put of by them. Only because coppers when they melt will do less damage. But iridiums for a standard boost car will be fine. Iridium are defo the BEST plug but are expensive and don't like any poor running.

 

[pegliobaglio]

Cheers for the info mate,ws considering the afm as I have recently fitted a apexi filter so could be something to do with that.
I have only done about 8k miles in 2 years in my car I think this will be my 2nd or 3rd set of plugs so I might give the ngk a try,my car runs about 1.1-1.2 boost ,would I need a colder rated plug or would these still be ok?

 

[LuPix_S15]

Hey dude - I'll have a look at this with you on Thursday

Turbo related gaskets failing - you can usually check by putting a piece of silicone hose against one ear and the other end around the gaskets like a stethoscope. Where it's leaking you can hear a 'chuggy/flapping' type noise (lol). You can also smell fuel/fumes when pulling up or even driving if it's getting worse!


I thought Iridiums are meant to last for a while?? So could be coilpack (the one nearest bulkhead is usually first to give up) as if you've changed yours within 12 months it seems unlikely to me. Worth checking though as everyone says...

 

[pegliobaglio]

Cheers buddy! That would be cool,I have done my turbo to elbow gasket and every gasket from there back when I did my elbow. I have the mani already so just need to get gaskets and that will eliminate those then as well.
Need to check when I last changed my plugs may have been just over a year thinking about it,be worth changing them anyways as not an expensive job really.
After changing both these if there is still a problem I guess time for uprated coilpacks and a z32 maf lol any excuse ha ha

 

[S15_SAM]

Well I run 1.1-1.2 boost, mine were in when they were mapped my Horsham. So whatever was in there when yours was mapped would be the safest bet!
I would have thought the bcpr7es are ok for yours, I have mine gapped to .28 thousands or .711mm. But its personal preference so stick with iridiums if they've been good for you!

Mine runs apexi air filter too and iduction kits have always been bad for AFM, so defo worth a shot. Coilpacks are aalot more harsh when they shut down. And generally on full throttle.

 

[LuPix_S15]

Yup if it's process of elimination, start with the cheapest then move towards the ones that are part of your modding plans lol :wack:

 

[pegliobaglio]

Cheers guys. Might stick with iridiums then as they have done me alright so far,the car was nismo tuned before it came over and I had a full service /fluid change etc when it arrived so don't know what were originally oin there,but as you say these have been fine so will prob stick with them for now,might clean the maf and whack my old air box on to help the elimitnation process,if its the induction messig the maf will wait till my z32 is here and get it remapped at the same time as I also have a fmic mani and fuel pump to go in