All hail NGK gods

[asian312]

U think I'm joking Well I'm not. About 9 months ago I began seriously tuning my GST, building in reverse order in preparation for a new turbo. It quickly accumlated to AFC, AVCR, intake, exhaust, FMIC, BOV, TT . . . but at this point I was getting a hesitation/bogging sensation when building boost. Well I was able to narrow it down to 3 possibilities:

1) Ignition system
2) BOV leak or IC leak or Venting to atmosphere
3) T25mall was dying a horribly painful death

Well I changed the spark plugs (Boshe Plats - I know I'm a fool), and checked everything else and still could not come to any solution. That is of curse until the fine ladies and gents here at DSMtuners wrote that thing up on spark plugs and the warning on Boshe Plats. I quickly ripped them out and slapped in some NGK BRP7ES. At first it was an antique V8 grumble and die idle which really had me confused, but then I realized I didn't check the gap. Well they came set at ~.040, so I regaped them to .030. Let me tell u, LIGHT and DARK baby. Happy to say I'm pumping every ounce of juice from that T25 (runnin bout 18-19 psi, but itching for more) and wow. Normally I'ld line up to a honda, pray, tribal dance, and cross fingers to win, but I was hunting GTs this past weekend. So in lamens terms, CHECK YOUR PLUGS. specially to all those who experiance "hesitation/bogging." And Thank you to all members who make this forums what it is --> DSM paradise!

Sorry so long. It's late . . . . ZZZZzzzzzz

 

[Megaman]

Originally posted by asian312
So in lamens terms, CHECK YOUR PLUGS. specially to all those who experiance "hesitation/bogging."

i will if it ever happens.

 

[larryd]

hence the reason plugs/wires are one of the first things you should change on the car

 

[MaineDSM]

Same thing happened to me. I had put in some NGK platinum plugs without gapping them, and my car was running like crap for over a year before I put in standard NGK BPR6ES and bought a $3 gapper from Sears. Gapped those bastards to .028, and everything ran like it was new.

This is what happens when you have someone who's car experience ends at changing the oil start modding a vehicle.

Ah, well, live and learn. I can now swap turbos, so I guess I've progressed.

 

[Newlogics]

Well, can someone explain this then:

Friends '90 GSX started bogging like crazy from about 4K to 5.5K rpm under WOT. We checked for any boost leaks - perfect.
Wires are magnecores, so I thought they shouldn't be a prob.
We took sparkplugs (NGKs) out and they were gapped at about 40 (makes sense, since specs were switched around with N/Ts in the manual, so whoever installed them last, gapped them wrong)
I regapped them to 28. Car started idling like a v8. Took 'em out again, regapped at 30-31. Idle is perfect, but RPM gauge jerks, however, the bogging at WOT decreased signifficantly.
We increassed gap to about 36, and that alkmost fixed RPM gauge needle jerking, but added to hesitation at WOT.

It seems like a trade-off between idle and WOT, the only problem is that it's mostly stock (only boost at 15) and shouldn't have that problem. We even tried silver plugs just for comparison, but got identical results.

 

[CL MaNTis GST]

hmm... i might need to pick up a set soon.

where can i find the NGK BRP7ES? any autoparts store? or do they have to be ordered?

thanks!

 

[L2RTSiAWD]

They mostly have to be ordered but you can order them from any parts store.

Let me tell you my BPR7ES contimued to work even with #1 plug well full of oil.

 

[asian312]

Newlogics - What plugs did u get, 6 or 7. And what level of modding/tuning? Mine idles normally and just ramps at WOT.

CL MaNTis GST - I got mine from pepboys for about $7.00 if I recall. The total bill was $11.00 and the only other thing I bought was a Puraltor oil filter

 

[Newlogics]

Originally posted by asian312
Newlogics - What plugs did u get, 6 or 7. And what level of modding/tuning? Mine idles normally and just ramps at WOT.

CL MaNTis GST - I got mine from pepboys for about $7.00 if I recall. The total bill was $11.00 and the only other thing I bought was a Puraltor oil filter

The plugs are 6s.
This 90GSX has been a mystery all the time.

My 91 GSX doesn't show any sign of idle or WOT hesitation with same xact plugs.

On this crooked 90GSX, we've played with gaps for several hours, and simply couldn't get a normal idle without WOT hesitation. I know for sure that gap plays some role here, because we did get better idle with higher gap, but better WOT operatio with lower gap, but there must be something else contributing to this.

What else can do this ? Faulty ignition coil ?

Some ppl suggested a fuel cut, but there is absolutely no reason for a fuel cut. boost is only 15psi. On my 91GSX i run 18psi with richened SAFC settings, and still don't see a single sign of fuel cut.

 

[asian312]

Sounds like a problem with in the ignition since your experiancing this from idle. Or possibly something with your idle setting?? I'm a novice tuner and just upgraded from oil changes (ok so I've ripped most of the car apart as well) but that's where i'ld start.