detonation

[.38 special]

Recently my car was popping and detonating at full boost. Fuel pressure gauge showed fuel pressure dropping. So I replaced the 3 year old walbro with another and replaced my stock injectors with 50#. That got rid of the popping and falling on its face, but the detonation is still there. I am running very rich and the boost is at 14 pounds to be safe. but it is still detonating at high rpms. The car is also smoking--maybe unrelated--I suspect turbo seals are going out. Could the detonation be caused by bad valve springs? If not, then what is causing the detonation and what else could be causing the smoke? Leak down show good compression.

 

[TT/Ameasap]

Prolly rich KR. Turn FP down and get 02's in 780-820 range.

Check your plugs,02 sensor and cat.

 

[.38 special]

02's are good, cat is empty, and plugs and cables are new.

 

[alex]

Pull the up pipe off and see if there is oil. If you are running
passenger valve cover breather and there is oil in the up pipe,
then the compressor side seal is probably bad. If thats the case you pushing oil to the engine. Oil reduces octane causing you to knock and smoke.
Alex

 

[.38 special]

There is oil in the up pipe. I know that, and I think that is where the smoke is coming from. But the bucking and popping quit when I changed fuel pumps. The detonation is what I'm worried about. Would the oil cause it to detonate? Please, Alex, explain to me why the passenger side breather would have any thing to do with it.

 

[alex]

Oil will lower octane rating, when you boosting your car
you pushing a lot of air and oil with it. Not enough octane = knock.
If you have a stock set up then the fumes from valve cover are
vented in to the turbo inlet bell. After a while you can collect quite a lot of oil in intercooler. If you still have the stock set up take it off and install valve breather then clean the intercooler and up pipe and drive it for a while ... If you get oil again than its a compressor seal. Makes sense?
Alex

 

[.38 special]

Yeah that makes sense Alex. I do already have the breather instead of the stock setup. I just didn't understand what you were saying on your last post, thanks for clarifying. I did fix the problem yesterday though--I stopped the detonation. It was the chip. I bought a new chip with the new 50# injectors. It was a 93 octane street chip, but apparently the timing was just too aggressive. I replaced it with another 93 street chip and it stopped the detonation. However I don't know why the car wouldn't handle the timing--after all it is a popular Conley's programmed chip. And my car is still much slower than it should be. SIZE=3]anyone got any ideas[/SIZE] maybe its just slow because of the seals in the turbo and the oil in the combustion chamber.[