turbo? Knock sensor? running lean?

[west_side_supra]

ok well ive put more gas in, and it was running fine for about 3 days then i pushed it hard and long and the check engine light came back on, did that slow down thing almost as if the clutch was slipping. but thats definatly not the case. so i went around asking my local shops and car peoples what they think it may be this is what i have gotten so far

1.Injectors
2.Fuel filter
3.Accordian hose (inlet pipe for turbo that ugly rubber thingy)
4.timing
5.CAT
6.oxegen sensor <that didnt make sense to me because if it was that the case then the light would be on all the time

[IHateHacks]

I'm telling you, you are running too much boost.

You can rule out 80% of what this "shop" told you.

You can check the resistance of the fuel injectors, 1.8-3.4 ohms for turbo models, but I already have the feeling you need bigger ones, and a bigger fuel pump running that much boost.

You should have replaced the fuel filter before you even started driving this vehicle so if you haven't yet, do it.

Accordian hose? Take it off and check for cracks. Better yet, check ALL vacuum hoses for cracks, i.e. ISC hose, PCV hoses, etc.

Like the fuel filter you should have set base ignition timing before you registered this vehicle.

You can test the O2 sensor voltage feedback. Connect a voltmeter to terminals Vf and E1 of the check connector. Voltage should fluctuate 8 times every 10 seconds.

And the cat, well you will have to take it off and look at it to see if its melted.

Or you can turn down the boost and see if thats the problem.

"did that slow down thing"- yeah thats the ecu retarding the timing, like I told you before.

[west_side_supra]

ok well i dont wanna sound stupid but where is the fuel filter on this car, im use to working on old chevy motors getting use to the import thing

[IHateHacks]

Bolted to the body, above the fuel tank.

Hope you have small hands and a 14mm flare nut wrench.

[west_side_supra]

ok well i have taken the 2nd cat off going for the 1st one

does it look clogged?

[west_side_supra]

anyone???????????

[jfunez]

cant really tell...

[ddouglas77]

Originally Posted by SideWinderGX

knock is the preignition of gasses in a cylinder. it happens if you ahve too high of an octane in your car, or if you mix them.

although, i dont think mixing gas matters as long as its the same octane. maybe it was a bad batch from one station that messed up yoru entire system.

um, if the blow off valve is leaking, thats obvoiusly not a good thing, although im not sure how that would relate to knock or anything messing up.

No, preignition happens if your octane level is too low, not high. The higher the octane, the cooler the burn, which is why it is only supposed to be used for boosted, nitro or high compression engines.
The BOV leaking under vacuum will more than likely leak under boost, which will cause a lean condition.

[new288sup]

Originally Posted by IHateHacks

I'm telling you, you are running too much boost.

You can rule out 80% of what this "shop" told you.

You can check the resistance of the fuel injectors, 1.8-3.4 ohms for turbo models, but I already have the feeling you need bigger ones, and a bigger fuel pump running that much boost.

You should have replaced the fuel filter before you even started driving this vehicle so if you haven't yet, do it.

Accordian hose? Take it off and check for cracks. Better yet, check ALL vacuum hoses for cracks, i.e. ISC hose, PCV hoses, etc.

Like the fuel filter you should have set base ignition timing before you registered this vehicle.

You can test the O2 sensor voltage feedback. Connect a voltmeter to terminals Vf and E1 of the check connector. Voltage should fluctuate 8 times every 10 seconds.

And the cat, well you will have to take it off and look at it to see if its melted.

Or you can turn down the boost and see if thats the problem.

"did that slow down thing"- yeah thats the ecu retarding the timing, like I told you before.

Alright, Knock sensors Detect ANY knock, Rod, crank, or cylinder (pre ignition/detonation) running to lean (not enough fuel) causes Detonation which is basicly the fuel igniting before it is supposed to Because the piston/cylinder walls are TOO hot. Pre ignition is similar but it is normally caused by carbon/deposits on the intake valves getting hot and falling into the combustion chambers and could also cause (if hot enough) the intake valves to ignight the fuel on the way in.....RICHER IS better on boosted engines. anything more then 12ish pounds on stock fuel system is asking for trouble. In my humble opion replace your fuel pump, and regulator first.
the more pressure/flow you can give your injectors, the less the injectors have to work for the same amount of fuel....
Also Look up "top tier" fuels in your area, and try to stick with them.

If you are still having issues, then its not your fuel. ITs an engine knock.
Could mean 2 things, Wear on your bearings from too much boost and not enough oil pressure, or just not enough oil pressure for the boost you are running (pumps create FLOW NOT PRESSURE) (resistance to flow creates Pressure).....there is a thread im still looking for on here that mentions replacing the pump spring in the factory oil pump with one from a SB chevy, im still looking for the exact details.

Now keep in mind i am build a 600HP 7m, Using MsEfi, and a few other tricks... no, its not done yet, but if the math works out, i can make it 600 and a daily driver
Nick

[jrok]

check for short to ground in the knock sensor wire