HELP! Stumped!

[Mike98GSX]

First off, I'd like to say prior to this incident, my car was running flawless.

Last night around 8PM, I started my car up (1998 GSX) and let it idle up to operating temperature before taking off to my destination. The car started and idled just fine to operating temperature. I was approaching the exit to my apartment complex, and out of no where the car sounded like it began to run on 3 cylinders and lost power. I pushed the car home (in the middle of winter) through my apartment complex back into my garage and began to see what was wrong with it.

- I have spark
- I have fuel
- Checked the timing which appeared to be on time
- Did compression test (150, 145, 145, 150)

Now I've pulled the plugs out and have them sitting right here. They look pretty fouled out, each is well caked with carbon build-up. I'm a skeptical person as it is, I find it hard to believe that all that is wrong, is these plugs are bad. Is there anything else that could or would happen that would cause my car to do what it did? Or should I just go grab another set of plugs, bolt them in and hope it works? I guess I'm looking for more of an answer. I've been through hell and back as it is with this car and my old GST.

My dad is saying that it might be the crank sensor. I've replaced the cam sensor earlier this year, which I don't think that's the issue because the car would start even with that sensor being bad. I really don't know what's wrong with the car and I'm just looking for some answers or ideas. If anyone has any, PLEASE! Let me know!

Thanks in advance for the help!





EDIT: (Mod-List)
BOTTOM END:
-4G64 block .20 over (87mm), align bored & honed
-Eagle ESP H-beam rods
-Wiseco 8.8:1 pistons
-Polished & deburred UNTURNED 4G64 crank
-.004" (~.1mm) piston-to-wall clearance for expansion
-ACL Race tri-metal main & rod bearings
-Concept Racing [CRCO] MBCAD [main bearing cap alignment dowel] kit
-All new OEM seals (front/rear main etc)
-Balance shaft elim
-ARP 2000 rod bolts
-ARP mains

2G HEAD:
-Crower 101200 cams (FP2/272 copies)
-Fidanza adjustable cam gears
-Cometic MLS high pressure head gasket (C4235HP)
-5 angle valve job and very light porting/runner cleanup
-All valve stems and guides replaced
-ARP head studs
-Greddy catch can
-3G lifters

HAIRDRYER:
-GT3076R, anti-surge comp cover, internally gated, 7cm ported turbine housing
-2G exhaust manifold, heavily ported and tapered at the collector to 7cm
-Earl's oil filter fed from head location with restrictor fitting
-10AN oil drain, billet oil pan fitting, Aeroquip hose
-Hallman MBC @ 15psi

DRIVELINE:
-ACT 2600
-Fidanza flywheel
-SS clutch line
-B&M short shifter
-Redline in diff & T-case
-Cruise delete cable (have all OEM cruise components)

SUSPENSION:
-Ground Control coilovers
-Tokico Illumina 5-way adjustable shocks
-Energy Suspension motor mounts
-New front axles (lifetime warranty)

EXTERIOR:
-VIS Racing G-speed carbon fiber hood
-6000K HIDs (8000K bulbs included)
-New front bumper freshly painted
-Color-matched center taillight
-Rota Subzero 18x8s
-Fuzion ZRi 225/40 tires (70-80%)
-Smoke clear corners

INTAKE:
-Apexi Hybrid FMIC (off an Aussie Skyline GTR)
-2G intake manifold ported to 60mm (1G TB)
-Forced Performance 4" intake w/ recirc
-Magnus phenolic intake manifold spacer
-1G throttle body w/ new seals
-2.5" SS piping w/ all T-bolt clamps
-Forge RS BOV

FUEL:
-Aeromotive FPR
-STM fuel filter to rail feed line
-FIC 950cc injectors
-255lph 'quiet' fuel pump
-New OEM fuel filter

COOLING:
-Koyo radiator (2x stock thickness)
-12" SPAL fans
-170deg thermostat

EXHAUST:
-VRS 3" O2 eliminator, downpipe, catback, Magnaflow muffler w/ silencer
-Magnaflow high flow catalytic converter (not installed, bolt-on, for inspection)
-O2 bung welded into 3" test pipe for Bosch wideband

ELECTRONICS & MISC:
-DSMLink v2.5
-EPROM ECU
-Zeitronix wideband w/ 52mm LCD gauge (shows Lambda, AFR, boost, EGT)
-TRE EGT probe & 3bar electronic boost sensor (for Zeitronix)
-ProSport 52mm white/amber fuel pressure gauge
-ProSport 52mm white/amber oil pressure gauge
-Energy Suspension shifter bushings
-Brass shifter cable inserts
-Remote oil pressure sender
-Optima Red Top battery in trunk
-Pioneer MP3 head unit w/ XM add-on
-Dual (Best Buy) 6.5s & 6x9s

 

[mickdragracer]

What injectors are you running and stock maf ? Etc fuel pressure plug brand. I had a similar issue with my 90 Gsx and I ended up having a cracked injector so hit me up and ill do what I can to help but need to know what mods you have done as well to help diagnostics

 

[ramsack]

If you have spark and fuel then your crank and cam sensor are just fine. How did you verify you have spark? How did you verify the injectors are spraying fuel? I'd get new plugs just for the hell of it if they look old.

 

[Mike98GSX]

I've added the mod list in my original post. To verify spark, I took the current plugs out of the cylinder head, plugged them into the plug wire, held them close to metal and watched all 4 create spark.

I'd also like to add that I have had a bad AFPR for the past couple months as well. I have the gauge in my car and every time I hit the gas the gauge peg's out to 100PSI, so I always assumed that the AFPR was probably bad or the diaphragm was bad. So could the AFPR fouled the plugs out to make the car stop working?

 

[ramsack]

Yes, that is likely. Why not just rebuild it?

 

[Mike98GSX]

Yes, that is likely. Why not just rebuild it?

I'll have to either rebuild it or get a new one, for sure.


I'm going to grab some new plugs the next couple days, I'll see if that works. I'm hoping that I don't have anything else going on.

 

[ramsack]

I wouldn't bother doing anything until you rebuild that AFPR or get a new one. I see no reason to get a new one unless it's some off-brand. Even nameless ones are copied identically from name-brand ones enough to where the name brand rebuild parts will work just fine.

 

[92AWDHX40]

fpr you have one so your set on that.

 

[90dsmboy]

I'm thinking bad tps and result of improper open throttle reading. Might be flooding your cylinder.

 

[CrawlinZX14]

I would start with your AFPR. But as your boosting your fuel pressure will rise. Thats what that vac line on your AFPR is for. As you add boost you add fuel pressure to compensate for the added use. If you take your base pressure, add what your boost is set at, and that should be about where your AFPR should read out. So say you have a 50psi base and 15psi boost, you should see 65-70psi on the gauge at boost.

After that I would suggest checking your TPS and MAF. either of those not metering properly can cause all kinds of issues. TPS telling your ecu your more or less on the throttle will cause all kinds of issues. And a maf feeding misinformation about how much air is in there can do the same.