Stuttering On Decel/cruise

[kosmo90]

Hi guys, have a new problem.

As the title suggests, i get a stutter while cruising. It boosts and idles ok but i cant seem to find the problem.

It did happen about six months ago, i thought it was the fuel pump dying so i swapped it out and all was good until now.

ecr33

Nistune

Hypergear ss1pu

3inch exhaust 100 cell cat

660cc high flowed jecs

yellow jacket coils

Old fuel pump was walbro 341? new is walbro f9000267 400lph with the 12v mod

Things ive checked so far

AFM (z32)

changed spark plugs

changed fuel filter

vacuum leaks

The only thing that i haven't changed is the fuel pump sock/strainer, this is still the original Nissan one.

Has anybody heard of/had this problem?

I'm leaning towards the fuel pump sock being dirty but i'm not 100%. Just wanted some ideas of things to check before i stick my arm in fuel again

Any ideas? I tried google and i only come up with 4-5k rpm stuttering issues, cant find anything too close to my problem unless i'm typing it in wrong.

Cheers

[DVS JEZ]

Explain the issue a little more please.

If the fuel pump wasnt supplying enough fuel at cruise u would expect the same on boost which means ur issue would be on boost as well.

Im thinking it may be an 02 sensor issue.

Try disconnecting the 02 sensor and going for a cruise to see if the issue is still there

[kosmo90]

Hey mate, sorry I didn't mention but I did try disconnecting the oxygen sensor and it made no difference.

The stuttering is only light, it doesn't feel like it's cutting out and it doesn't throw you around the car if you know what I mean.

[kosmo90]

Just checked Nistune (which i should have done in the first place) and i have a code 51 injector circuit error.

Anybody have any ideas?

Cheers

[Dobz]

Put it on a dyno to check fuel mixtures. It sounds like they're leaning out on cruise.

Does it only do it at low rpm when cruising?

[kosmo90]

It seems to do it between 60-100 kph, that's all ive noticed. Guess im accelerating up to those speeds before then.

I'm due to go back to the tuners next month now anyway, i'll check the resistance on the injectors and try and troubleshoot anything else while im at it.

I was leaning towards the fuel pump strainer before i saw the code 51 but like Jez said, it would probably do it the whole time if it was blocked.

[DVS JEZ]

Let us know what the tuner finds

[kosmo90]

Yep, will do.

I changed the fuel pump strainer and the old one was filthy but no change.

Im also on the market for a new set of injectors, these cheap high flows were a bad decision i think.

Just looking at sard 550's and they come in one or two hole, both for r33. I'm assuming that that's phase 1 and 2?

I'm trying to google a bit of info on them, if anybody knows anything about which would be better or some general info. That would be great

[DVS JEZ]

Try and find some nismo 555cc or similar. Or any high quality injector. Even if u go 2nd hand. Just get them cleaned and tested

[kosmo90]

Ok, thanks for the help Jez