My Turn To Rant

[DevilMB3017]

Cliff Notes At Bottom:

So after fixing so many issues plaguing my car for so long, I was finally able to start driving it a lot recently. I drove it to work (50 miles round trip) four times last week to see how well it was holding up. Some minor adjustments to things like the fuel pressure and double checking all kinds of things all the time led me to be very, very happy with the way the car was running.

And then came a dyno-day on Sunday. I was so excited to see how much horsepower my car was really making. It's on a DynaPack dyno, so I knew not to expect crazy numbers. My car peaks at about 17 pounds of boost on the dyno. The most it's ever hit. The dyno read out 257 rwhp.

Luckily we had the consult port hooked up to a laptop the entire time. My TPS died. Knock sensor fault code. The timing was pulled back like crazy after about 4,000 RPM. So all in all I was upset that I only hit 257rwhp, but amazed I did that with the timing going all over the place and with no TPS and a bad knock sensor. I'm hoping to fix both of those problems and call this one a mulligan and try again.

And then I see some coolant. One of my hoses is leaking by the clamp. A teeny tiny pin hole were coolant was coming out in a stream. Great. Easy to fix, but annoying none the less. One less hose in the way of the knock sensor process though, right?

And then the car dies on the way home. I only live about 5-10 miles from where the Dyno Day was being held. Check fuses. Fuel pump fuse has popped. Replace. Go about 100 yards. Fuse pops. F-bomb. After probably an hour of messing with and testing the relays, fuel pump, fuses, etc., we said screw it and limp home with the fuel pump connected directly to the battery.

Cliff Notes1) Car drives fine 200 miles during week2) Dyno comes, TPS and knock sensor die3) Lay down 257rwhp with no TPS and knock sensor code4) Coolant hose is no good5) Stuck on side of road with no fuel pump6) Limp home with fuel pump directly connected to the battery

[kouki_hmongster]

damn that realy sucks, what caused the TPS and knock sensor to go out?..should i replace it now so that i wouldnt have to worry about it later? you have enthalpy ecu right?

[DevilMB3017]

The TPS has given me issues before.

As for the knock sensor, just a fluke thing I guess. Sometimes they last, sometimes they don't. I'd suggest talking to your ECU tuner about removing it. In a performance car, they aren't always a good idea.

[kouki_hmongster]

i'm getting an enthalpy tune so that mean i wouldnt need it? i just hate playing the waiting game w/enthalpy. right now i'm just waiting for a reply so i can send in my ecu...Honestly as long as the tune is good i dont really care.

[spooled240]

i get a CEL from my knock sensor with my JWT, it's just a fluke because I have no CEL with my stock ecu. I would check your ecu and some sensors, maybe the popped fuse was a safety precaution to your CEL issues.

[DevilMB3017]

The thing is there is no CEL. Consult port is showing a faulty knock sensor. I think it might actually be bad, lol.

It wasn't showing that code as of a week ago, or two weeks ago...

[spooled240]

my cel showed up the second I fired the car up with the jwt ecu, but the car drives fine.

I heard that the knock sensor only controls timing in the lower rpm ranges, to safeguard the engine against lousy gas. I suspect all your issues are connected to one problem, since it happened all at once.

knock sensors are 140ish brand new last time I checked.

[DevilMB3017]

Well my datalog shows the timing at 3.5K or so and up going to hell in a handbasket. :p

Maybe the Enthalpy tune is different.

Also, I'm sure the TPS isn't good. My guess is the ECU is staying in open loop at WOT. Combined with the knock sensor fault, and the car is in safe-mode.

I picked one up on eBay super cheap this moring. Thanks :p

[480sx]

What a strange way for a dyno to pwn a car..

Just sounds like a bunch of little things that kinda blew up all at once. Shouldnt be a big deal to fix that stuff. GL though, the fuel pump fuse should be the fun one.

[DevilMB3017]

I know man, it's unreal. This car pulls hard as hell all week, and then TPS and knock sensor combine to demolish my dyno runs.

At least my motor is still 100% AFAIK. It didn't even run rich/lean on the dyno, it just pulled timing. Impressive fuel maps, IMO.

Seeing my wideband read 'air' when the fuel pump wiring shorted scared me.

Thank God it didn't happen at full throttle on the dyno...I guess I should take whatever luck I can, right?

[spooled240]

yeah you are a lucky bastard if you look at it that way lol

I bet the fuel pump fuse was a safeguard like I said before it seems very unlikely that you short-circuited somewhere. I'd say get that knocksensor in and change the fuel pump fuse and see how she runs

[DevilMB3017]

We did change the fuel pump fuse...On the side of the road. I have no lights, horn, or blower motor right now... haha

They all popped. 10 and 15 amps just to limp home. Plug connector from fuel pump directly to battery in the trunk, and drove home.

When I think about it, I'm REALLY lucky. If the fuel pump stopped at like 6K RPM...that'd be bad news man. Oh well. I'll fix it and keep on boosting till I break something else. lol

[WDRacing]

Damn bro...quite the event

Fix and retest...that retarded timing is killing you. Crazy about the fuel pump...any idea's yet?

[DevilMB3017]

Damn bro...quite the event

Fix and retest...that retarded timing is killing you. Crazy about the fuel pump...any idea's yet?

KA-T...Always an adventure.

I keep pouring over these logs. The more I look at the way the ECU was responding, the more I'm sure my TPS has had problems for a while. I bet a lot of drivability and throttle response problems will be gone.

All the relays appear to be testing OK. I'm going to limp the car to the shop later this week.

New Question

Anyone know adverse affects of wiring the fuel pump directly to the battery (with an inline fuse of course) and putting a switch on that near the driver seat? I can't see the relays controlling anything else in the FSM... This also is theft prevention, lol.

[480sx]

Ghetto but it works. Its actually a recommended mod for a 240 to hardwire your fuel pump(at least for a s13), something about the stock lines and relays having the possibility of not being able to deliver enough juice to a high volume pump.

[KFL]

KA-T...Always an adventure.

I keep pouring over these logs. The more I look at the way the ECU was responding, the more I'm sure my TPS has had problems for a while. I bet a lot of drivability and throttle response problems will be gone.

All the relays appear to be testing OK. I'm going to limp the car to the shop later this week.

New Question

Anyone know adverse affects of wiring the fuel pump directly to the battery (with an inline fuse of course) and putting a switch on that near the driver seat? I can't see the relays controlling anything else in the FSM... This also is theft prevention, lol.

Yep the dyno pulls sucked..I was expecting some big numbers from your setup. I have a s13 tps if you need. Knock sensor is a ghost code always has been to my knowledge on maximas/240s similiar. Basically it doesn't throw a CEL for it, you have to scan for it. I think in later 96+ obd2 there is a chance of it throwing a CEL thoughCorrect way to hard wire a fuel pump.. http://ka-t.org/s14_walbro_rewire.php

[DevilMB3017]

Hey Alex. Did you end up running your car or not? Having problems still?

Tommy said he's got a bunch of TPS's lying around the shop. He just has to remember where, lol. I found a dirt cheap knock sensor on eBay and plan on dyno'ing this thing in the next week or two again.

480SX, I've heard that but never had a problem. Looks like I'm in that boat now.

As for the fuel pump wiring, the stock trigger is not working. The pump power line in the back of the car is not getting power. I'm thinking of eliminating the stock wiring.

It'll go like this...

Battery --> 10Amp Fuse --> Relay --> Fuel Pump

That relay will be on when the ignition is on. Alternate idea is...

Battery --> 10Amp Fuse --> Switch --> Fuel Pump

This why there is one less possible failure AND the car can't start without that switch... lol

[spooled240]

the second setup will require a heavy duty switch to handle all the voltage and amps directly from the battery.

how about

battery --> 10 amp fuse --> relay --> fuel pump

**with the relay getting 12v power from a small, low amp hidden switch somewhere.

[480sx]

I would do the relay and the switch, a FP kill switch is a really sweet anti theft device. 240's are a target for thieves, s13's are so easy to break into and hotwire. Never can be to careful.

[DevilMB3017]

I would do the relay and the switch, a FP kill switch is a really sweet anti theft device. 240's are a target for thieves, s13's are so easy to break into and hotwire. Never can be to careful.

This is going to be the most likely.

Now the fun begins of tracing the entire fuel relay wiring...

[KFL]

Yeah I fixed my small leak..after it cooled down.. I did what I figured I would. Will post tommorow most likley..Going to help buddy with his ka soon though, bad ks also I think. Your next dyno will be awesome number..

What are you using to data log afrs or actually timing you logged also. I want to log timing on my friends car as well as mine.
Modified by KFL at 2:57 PM 9/27/2008

[kouki_hmongster]

KA-T...Always an adventure.

I keep pouring over these logs. The more I look at the way the ECU was responding, the more I'm sure my TPS has had problems for a while. I bet a lot of drivability and throttle response problems will be gone.

All the relays appear to be testing OK. I'm going to limp the car to the shop later this week.

New Question

Anyone know adverse affects of wiring the fuel pump directly to the battery (with an inline fuse of course) and putting a switch on that near the driver seat? I can't see the relays controlling anything else in the FSM... This also is theft prevention, lol.

When i bought my injectors from Deatschwerk they gave me a hardwire kit which you can part your own and how to install for the s13 chassis. i took a lot of pictures hopin to find time to make a install thread but i'm starting to get busy since school started. so if you want pictures of how i did it and what the parts required then email me at [email protected]