219GTP Knock Monster

[ProjectGTP]

Ok I'm posting for 219 GTP. We just got the car back from SDD/Rob. I'm sure everyone knows the deal with that. Here's what's going on. We got the car together, it has a ported gen 3 on a 3.4 pulley, s1x, slp headers. We took it for a test drive and under just half throttle it gets almost 10 degrees of knock. Rob says it is a fuel issue. We tested the fuel pump voltage and it was at 12.6 while idling. So I did the resistor bypass mod thing with the relay and its at 13.1 now. We just took it for another text drive and the same results happen. 02 readings are around 850+ at wot. Also the cars starts showing kr when the torque converter is in full lock up at half throttle. Anything else to measure? He has a aeroforce for scanning.

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[Mook]

is knock spiking immediately or gradually building? you sure something isnt rubbing or causing vibration? could be false knock. just a thought.

whats the injector duty cycle look like? i only ask because its being mentioned it could be fuel related.

 

[RICH17]

How is the car running tho? Check anything around the knock sensors and make sure theyre not loose and neither are the wires. Could be a false noise issue. hopefully.....

 

[PANDA]

what "tune" is on the car?

stock TCC settings?

 

[ProjectGTP]

The last time the motor blew up it was doing the same thing. It's running the same way. The cat gradually increases I'm knock up to about 9.8. I'm guessing its still Ron vogels tune on the car. I'm not sure if we can check the injector duty cycle on an aeroforce. Also it has 42.5 injectors so they can't be maxed out. I'm going to put a fuel pressure gauge on it to see what its at under throttle. And also check around the knock sensors.

 

[PANDA]

Didnt Vogel say u had a bad/weak fuel pump?

 

[ProjectGTP]

Didnt Vogel say u had a bad/weak fuel pump?

Yes. Him and rob both said that. That's why I was going to put a pressure gauge on it. And if the pump was bad wouldn't the o2 reading be extremely low? Its around 850 880 at wot

 

[smug]

Test fuel pressure first

Is it a L26 build or L67 build?

My car when it was non intercooled, L26, 3.3 pulley, XP cam, headers, ect would see up 8 degrees of KR around half throttle as if I would pass someone. If I would roll into the gas as if I am launching the car from a dig it would be fine. It was just an awkward high load lower rpm making the KR. An intercooler fixed that issue.

 

[ProjectGTP]

Sorry I forgot to mention its an l26. Sounds like the same issue u are having. but its gotta be another way to fix this

 

[DanJ]

Zzp tc table ft

 

[birdkillingtp]

I'm also posting for 219 gtp what should fuel pressure be at idle and wot

 

[ProjectGTP]

Ok we got the gauge and the car says 42ish psi at idle. Then under halfish throttle its around 53.

 

[ProjectGTP]

Also the o2 readings fluctuate and go as low as 35. Is that normal?

 

[Turbocharged400sbc]

KOEO/atmospheric is 48-52
WOT is that plus boost psi (1 to 1 rising rate fpr)
idle is less than KOEO

and yes o2 switches lean to rich .001 to 100v is normal
read up on efi dude

 

[ProjectGTP]

KOEO/atmospheric is 48-52
WOT is that plus boost psi (1 to 1 rising rate fpr)
idle is less than KOEO

and yes o2 switches lean to rich .001 to 100v is normal
read up on efi dude

Ok I thought it dropping that low was weird. The fuel pressure is good under load so the pump is fine right?

 

[smug]

sounds like the pump is fine.

Just my experience is that L26 do not like a lot of boost non intercooled and with the cold weather it makes the problem worse because the air is more dense. Anyways you do need to go through everything including what ever tune is on this car and make sure everything is is proper working order.

Or put a stock pulley on lol

 

[ProjectGTP]

What about the knock sensor module? Maybe that's a stupid question.

 

[smug]

only a 97 had a separate kr module

 

[ProjectGTP]

Oh ok. I wasn't sure

 

[ProjectGTP]

I think something is causing false knock.

 

[Wizconsoncheezin]

race gas will determine real or false....

 

[10sec]

850-880o2's at WOT is way lean. Needs more fuel under load, that's the problem.

 

[PANDA]

Needs WB readings

 

[Handsome Jesus]

NB tuning sucks

 

[10sec]

and