Help!! My SC'd Z is cutting out.
06-08-2011, 07:06 AM
#21
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New found Issues
Ok..so since i first posted this, I thought the car was back to normal after cooling fully. Well it was just because i was babying it after that scare. I now have a constant issue.
As soon as i put my foot into it, hitting 4psi of boost or bringing the rpms up quickly, around 3200 rpms, it will bog. This happens in any gear and the ambiant conditions do not affect it. It starts rough also. It will only crank over on the second key turn.
I have contacted stillen and theyre techs are on it and supposed to get back to me today.
It feels and acts as though there is some sort of fail safe that is kicking in as soon as the engine feels like it needs to perform.
As far as the cats failing, im not ruling it out, but wouldnt the OBDII have picked that up if they were bad?
As soon as i put my foot into it, hitting 4psi of boost or bringing the rpms up quickly, around 3200 rpms, it will bog. This happens in any gear and the ambiant conditions do not affect it. It starts rough also. It will only crank over on the second key turn.
I have contacted stillen and theyre techs are on it and supposed to get back to me today.
It feels and acts as though there is some sort of fail safe that is kicking in as soon as the engine feels like it needs to perform.
As far as the cats failing, im not ruling it out, but wouldnt the OBDII have picked that up if they were bad?
06-08-2011, 07:10 AM
#22
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What doenst make sense to me on all this is that when the issue hit, it hit hard to where the car barely made it to a parking lot. When it cooled a bit it ran enough to get it home. Now it only happens when trying to push the engine. I havent experimented and ran it for an extended period of time to try to recreate the failure of the first instance since i know i could damage something.
06-08-2011, 07:29 AM
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with out the proper information or logs its hard to diagnose a problem lke this. It could be a number of things.
I would suggest either going to a shop and have it diagnosed or find some one with cipher to data log it for you so we can have a better undestanding of whats really going on. Otherwise its all just a guessing game.
Not sure if it was mentioned but your fuel pump could be going out as well.... or fouled spark plugs.
I would suggest either going to a shop and have it diagnosed or find some one with cipher to data log it for you so we can have a better undestanding of whats really going on. Otherwise its all just a guessing game.
Not sure if it was mentioned but your fuel pump could be going out as well.... or fouled spark plugs.
06-08-2011, 09:20 AM
#25
be sure to remember which cyl. # each plug comes from since they won't always read the same!
06-08-2011, 09:41 AM
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Ok will do. Im changing those tonight and then Saturday morning Im taking it to a guy i know that can put a cipher on it aswell as a nissan OBD and see if we cant figure it out. Hoping that its a bad plug though. Ill post the pics.
06-08-2011, 11:02 AM
#27
with out the proper information or logs its hard to diagnose a problem lke this. It could be a number of things.
I would suggest either going to a shop and have it diagnosed or find some one with cipher to data log it for you so we can have a better undestanding of whats really going on. Otherwise its all just a guessing game.
Not sure if it was mentioned but your fuel pump could be going out as well.... or fouled spark plugs.
I would suggest either going to a shop and have it diagnosed or find some one with cipher to data log it for you so we can have a better undestanding of whats really going on. Otherwise its all just a guessing game.
Not sure if it was mentioned but your fuel pump could be going out as well.... or fouled spark plugs.
06-08-2011, 12:01 PM
#28
The OBDII will pick it up if the signal is the same within a set of parameters... Normally the O2's for pre and post cat are reading two different signals so the system thinks it is operating fine. In your case, you can still turn on the car and exhaust is obviously flowing through the car, and it may be enough to allow the difference of the two O2's to tell the ECU that everything is working. Depending on the year, I know alot of 03-04.5's you can remove the cats all together, put on a set of test pipes, and the O2 sensors will never throw a code. My brother has done this on his Z for 45k, although not boosted, he has never thrown a S1B2 or S2B2 code.
Fuel pump may very well be the issue too.
Fuel pump may very well be the issue too.
06-08-2011, 04:13 PM
#29
I think i know what the problem is you either have a bad fmu or a stuck 7th injector that is dumping fuel.The only problem i ever had was with the fmu that came with the stage 4 it made the 7th injector deliver fuel all the time even when not in boost and it ran like a pig.Pull one plug and see if its running pig rich,,,if you had an A/F gauge you would know instantly.
06-08-2011, 05:01 PM
#30
I think i know what the problem is you either have a bad fmu or a stuck 7th injector that is dumping fuel.The only problem i ever had was with the fmu that came with the stage 4 it made the 7th injector deliver fuel all the time even when not in boost and it ran like a pig.Pull one plug and see if its running pig rich,,,if you had an A/F gauge you would know instantly.
06-08-2011, 08:18 PM
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06-09-2011, 06:18 AM
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Well I didnt end up pulling my plugs last night. The guy im taking it to said we will end up doing that anyway Saturday morning so i figure i can just hold off till then. Ill post pics of what each cylinder plug looked like after that and HOPEFULLY the root cause to this whole mess so that we can edumacate others.
Quick question though..This is probably related..But what does getting terrible gas mileage, with the issues im having, mean? When i took it to work that cool morning i was running low so the "due to empty" guage read 34 miles. By the time i got to work it read 15 miles. My work is only 5 miles away. Then i filled by work and reset the avg. mpg. readout and I was averaging 13.5 mpg. driving grandma style. It normally reads 20.5 or so driving aggresive.
Quick question though..This is probably related..But what does getting terrible gas mileage, with the issues im having, mean? When i took it to work that cool morning i was running low so the "due to empty" guage read 34 miles. By the time i got to work it read 15 miles. My work is only 5 miles away. Then i filled by work and reset the avg. mpg. readout and I was averaging 13.5 mpg. driving grandma style. It normally reads 20.5 or so driving aggresive.
06-09-2011, 08:58 AM
#33
Well I didnt end up pulling my plugs last night. The guy im taking it to said we will end up doing that anyway Saturday morning so i figure i can just hold off till then. Ill post pics of what each cylinder plug looked like after that and HOPEFULLY the root cause to this whole mess so that we can edumacate others.
Quick question though..This is probably related..But what does getting terrible gas mileage, with the issues im having, mean? When i took it to work that cool morning i was running low so the "due to empty" guage read 34 miles. By the time i got to work it read 15 miles. My work is only 5 miles away. Then i filled by work and reset the avg. mpg. readout and I was averaging 13.5 mpg. driving grandma style. It normally reads 20.5 or so driving aggresive.
Quick question though..This is probably related..But what does getting terrible gas mileage, with the issues im having, mean? When i took it to work that cool morning i was running low so the "due to empty" guage read 34 miles. By the time i got to work it read 15 miles. My work is only 5 miles away. Then i filled by work and reset the avg. mpg. readout and I was averaging 13.5 mpg. driving grandma style. It normally reads 20.5 or so driving aggresive.
06-09-2011, 07:52 PM
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Well I didnt end up pulling my plugs last night. The guy im taking it to said we will end up doing that anyway Saturday morning so i figure i can just hold off till then. Ill post pics of what each cylinder plug looked like after that and HOPEFULLY the root cause to this whole mess so that we can edumacate others.
Quick question though..This is probably related..But what does getting terrible gas mileage, with the issues im having, mean? When i took it to work that cool morning i was running low so the "due to empty" guage read 34 miles. By the time i got to work it read 15 miles. My work is only 5 miles away. Then i filled by work and reset the avg. mpg. readout and I was averaging 13.5 mpg. driving grandma style. It normally reads 20.5 or so driving aggresive.
Quick question though..This is probably related..But what does getting terrible gas mileage, with the issues im having, mean? When i took it to work that cool morning i was running low so the "due to empty" guage read 34 miles. By the time i got to work it read 15 miles. My work is only 5 miles away. Then i filled by work and reset the avg. mpg. readout and I was averaging 13.5 mpg. driving grandma style. It normally reads 20.5 or so driving aggresive.
06-10-2011, 07:36 AM
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I actually have one sitting in my garage. Not sure the quality of it however but i know it will fit in my guage cluster. I have a secondary oil pressure ill swap it with.
So what do you guys think of the problem possibly being a cam sensor or a clogged PCV valve?
Im leaning toward a carbon issue since it hit hard..then got a little better. and now is better in general but still thirsts for power and will bog when in high gears and i try to accelerate quickly.
So what do you guys think of the problem possibly being a cam sensor or a clogged PCV valve?
Im leaning toward a carbon issue since it hit hard..then got a little better. and now is better in general but still thirsts for power and will bog when in high gears and i try to accelerate quickly.