detonation, need new pistons
detonation, need new pistons
Well...here is the story,
I was pulling onto the highway in third gear. Floored the car and it boosted to 20psi. At around 5-6k rpms I felt a studder in the power. I glanced at the AFR meter and they are at 13.5 with full boost. I immediately lay off the gas. At this point the car is still running. I put it in fifth and go WOT from around 3500 rpm to see what the AFR's will do, it reached full boost and the AFR's go lean again. This is when the engine died and has not started since.
The car is tuned for 91 octane and afrs at 11.1-11.2 Data logging the car shows 10.8 AFR's at 7500rpm. Injector duty cycle at 93%. Something caused the car to go lean. I think it was the fuel pump. I just received the Walbro last week and had not installed it. I didnt have a problem with the stock pump at all. I still dont know if that is what caused it. I always run 100 octane in the car but could not get any since the gas station ran out this week. I filled up with 91 for the first time in two months last night.
Compression test starting with #1 150, #2 130, #3 120, #4 45.
Inside the #3 and #4 cylinders are small peices of metal. Presumably the ring land or parts of a valve. I wont know untill I pull the heads. I yanked off all the upper IC piping and turbo inlet hose. No visible damage to compressor blades and zero shaft play.
Oh well. I guess this is where I find out how good I am at building my own motor! I plan an in chassis swap of the pistons and rods as long as the cylinder walls are clean. Obviously ARP hardware through out.
Pics when I open up the motor.
25000 on the stock motor.
I was pulling onto the highway in third gear. Floored the car and it boosted to 20psi. At around 5-6k rpms I felt a studder in the power. I glanced at the AFR meter and they are at 13.5 with full boost. I immediately lay off the gas. At this point the car is still running. I put it in fifth and go WOT from around 3500 rpm to see what the AFR's will do, it reached full boost and the AFR's go lean again. This is when the engine died and has not started since.
The car is tuned for 91 octane and afrs at 11.1-11.2 Data logging the car shows 10.8 AFR's at 7500rpm. Injector duty cycle at 93%. Something caused the car to go lean. I think it was the fuel pump. I just received the Walbro last week and had not installed it. I didnt have a problem with the stock pump at all. I still dont know if that is what caused it. I always run 100 octane in the car but could not get any since the gas station ran out this week. I filled up with 91 for the first time in two months last night.
Compression test starting with #1 150, #2 130, #3 120, #4 45.
Inside the #3 and #4 cylinders are small peices of metal. Presumably the ring land or parts of a valve. I wont know untill I pull the heads. I yanked off all the upper IC piping and turbo inlet hose. No visible damage to compressor blades and zero shaft play.
Oh well. I guess this is where I find out how good I am at building my own motor! I plan an in chassis swap of the pistons and rods as long as the cylinder walls are clean. Obviously ARP hardware through out.
Pics when I open up the motor.
25000 on the stock motor.
Originally Posted by althemean
Well...here is the story,
I was pulling onto the highway in third gear. Floored the car and it boosted to 20psi. At around 5-6k rpms I felt a studder in the power. I glanced at the AFR meter and they are at 13.5 with full boost. I immediately lay off the gas. At this point the car is still running. I put it in fifth and go WOT from around 3500 rpm to see what the AFR's will do, it reached full boost and the AFR's go lean again. This is when the engine died and has not started since.
The car is tuned for 91 octane and afrs at 11.1-11.2 Data logging the car shows 10.8 AFR's at 7500rpm. Injector duty cycle at 93%. Something caused the car to go lean. I think it was the fuel pump. I just received the Walbro last week and had not installed it. I didnt have a problem with the stock pump at all. I still dont know if that is what caused it. I always run 100 octane in the car but could not get any since the gas station ran out this week. I filled up with 91 for the first time in two months last night.
Compression test starting with #1 150, #2 130, #3 120, #4 45.
Inside the #3 and #4 cylinders are small peices of metal. Presumably the ring land or parts of a valve. I wont know untill I pull the heads. I yanked off all the upper IC piping and turbo inlet hose. No visible damage to compressor blades and zero shaft play.
Oh well. I guess this is where I find out how good I am at building my own motor! I plan an in chassis swap of the pistons and rods as long as the cylinder walls are clean. Obviously ARP hardware through out.
Pics when I open up the motor.
25000 on the stock motor.
I was pulling onto the highway in third gear. Floored the car and it boosted to 20psi. At around 5-6k rpms I felt a studder in the power. I glanced at the AFR meter and they are at 13.5 with full boost. I immediately lay off the gas. At this point the car is still running. I put it in fifth and go WOT from around 3500 rpm to see what the AFR's will do, it reached full boost and the AFR's go lean again. This is when the engine died and has not started since.
The car is tuned for 91 octane and afrs at 11.1-11.2 Data logging the car shows 10.8 AFR's at 7500rpm. Injector duty cycle at 93%. Something caused the car to go lean. I think it was the fuel pump. I just received the Walbro last week and had not installed it. I didnt have a problem with the stock pump at all. I still dont know if that is what caused it. I always run 100 octane in the car but could not get any since the gas station ran out this week. I filled up with 91 for the first time in two months last night.
Compression test starting with #1 150, #2 130, #3 120, #4 45.
Inside the #3 and #4 cylinders are small peices of metal. Presumably the ring land or parts of a valve. I wont know untill I pull the heads. I yanked off all the upper IC piping and turbo inlet hose. No visible damage to compressor blades and zero shaft play.
Oh well. I guess this is where I find out how good I am at building my own motor! I plan an in chassis swap of the pistons and rods as long as the cylinder walls are clean. Obviously ARP hardware through out.
Pics when I open up the motor.
25000 on the stock motor.
--Josh
wasnt logging when it went. I was just relaying the info so people would know how the car was tuned.
I personally didnt tune the car. I am sure the knock control was all done. I asked for that feature to be there. I dont even own a laptop. I would have to drag my desktop to the garage to retrieve my tune. I will try to get it from my tuner on Monday.
Fact remains that the car ran great for one week with NO PROBLEMS of this nature. Believe me, I have been keeping my eye on the AFRS like a hawk. This happened all at once this afternoon. That was all it took. Some severe detonation to make it crap a piston.
I wish I wish I had installed that damn walbro. The main reason I didnt was because I wanted to get the base tune done before I started adding more parts. I was making sure all the part throttle stuff was taken care of first. If anything, the car still ran rich in some parts of the maps.
I personally didnt tune the car. I am sure the knock control was all done. I asked for that feature to be there. I dont even own a laptop. I would have to drag my desktop to the garage to retrieve my tune. I will try to get it from my tuner on Monday.
Fact remains that the car ran great for one week with NO PROBLEMS of this nature. Believe me, I have been keeping my eye on the AFRS like a hawk. This happened all at once this afternoon. That was all it took. Some severe detonation to make it crap a piston.
I wish I wish I had installed that damn walbro. The main reason I didnt was because I wanted to get the base tune done before I started adding more parts. I was making sure all the part throttle stuff was taken care of first. If anything, the car still ran rich in some parts of the maps.
I am just curious myself. The internal log usually logs realtime all the time. So you might just want to pull it to check it out.
Evo stock pistons are crap. My 2nd cyclinder blew too. Now I have a fully built motor that I did all myself. It was def. an experience. I did it all in a garage on the floor with jack stands.
Goodluck to ya.
--Josh
Evo stock pistons are crap. My 2nd cyclinder blew too. Now I have a fully built motor that I did all myself. It was def. an experience. I did it all in a garage on the floor with jack stands.
Goodluck to ya.
--Josh
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Originally Posted by SwiftEVO
I am just curious myself. The internal log usually logs realtime all the time. So you might just want to pull it to check it out.
Evo stock pistons are crap. My 2nd cyclinder blew too. Now I have a fully built motor that I did all myself. It was def. an experience. I did it all in a garage on the floor with jack stands.
Goodluck to ya.
--Josh
Evo stock pistons are crap. My 2nd cyclinder blew too. Now I have a fully built motor that I did all myself. It was def. an experience. I did it all in a garage on the floor with jack stands.
Goodluck to ya.
--Josh
The cylinders that went on my car were #4 and #3.
Well, tomorrow morning I will drag the desktop into the garage and see what I can pull out of the EMS logs then. Thanks for the advice. I will probably be in touch with you via PM's since you did the R&R the same way I was planning on, if you dont mind.
Local tuner. I dont know if he wants his name out. But the man knows what he is doing. It wasnt the tune. Believe me. I saw all the logs and the final tune was spot on.
Something caused the car to go lean.
Do these cars have a fuel filter? If so, where is it at? I looked in the service manual and didnt see anything under fuel filter. Of course I didnt look that hard yet.
Something caused the car to go lean.
Do these cars have a fuel filter? If so, where is it at? I looked in the service manual and didnt see anything under fuel filter. Of course I didnt look that hard yet.
Fuel filter is part of the fuel pump assembly (search the Walbro install at http://evomoto.com/tech_info.php?tPa...8086dfda3cf417) Section 10 and 13 show good views.
I seriously doubt the filter was clogged at all...it would take a heap of crap to clog it.
I seriously doubt the filter was clogged at all...it would take a heap of crap to clog it.
Originally Posted by 56Hotrod
Fuel filter is part of the fuel pump assembly (search the Walbro install at http://evomoto.com/tech_info.php?tPa...8086dfda3cf417) Section 10 and 13 show good views.
I seriously doubt the filter was clogged at all...it would take a heap of crap to clog it.
I seriously doubt the filter was clogged at all...it would take a heap of crap to clog it.
I need to rule out all variables that could have caused this condition. I dont want to put new parts in and have the same problem occur again.
I figure I am going to go AMS Ross pistons and Eagle con rods. My HP goals are only 350-400whp.
Last edited by althemean; Apr 1, 2006 at 11:29 PM.
This happen to me a month back now i got a build motor and its the best money ive spend so far. The pieces that your shop saw where pieces of your piston good luck with your build.