Random misfire occurs @ 6000 rpms, need help.
I just got my car back and the CPS cured my problem! The car runs smooth as can be, all the way to 7800 rpms! In addition to changing the CPS, my car was in for a tranny rebuild/ upgrade (double synchs, Evo IV MR 5th gear,etc) & I'm running the evil RP 75/90 W synthetic oil, upgraded two motor mounts, swapped out Tanabe 2.75" for a MR 3" DP to more closely match my full 3.5" exhaust. We want to try swapping back in the old CPS to see if the misfire returns, but I wont be able to do that until later this week.
The car is a frigen freight train in 5th gear now, I just about never have to down shift.
The car is a frigen freight train in 5th gear now, I just about never have to down shift.
Glad the CPS fixed your issue Sgt Blamo!
Still haven't gotten a chance to swap in another AEM on this car but hopefully soon. Been busy getting ready for the return of my engine from AMS and getting my car back on the road.
BTW swapping the CPS takes less than 5 minutes, it's one 10mm bolt that holds it on.
I'll update once we get time and figure out what is wrong with this car. I have done a fair amount of tuning on the car and it runs very well everywhere else though, and when it happens to not misfire its a monster.
Still haven't gotten a chance to swap in another AEM on this car but hopefully soon. Been busy getting ready for the return of my engine from AMS and getting my car back on the road.
BTW swapping the CPS takes less than 5 minutes, it's one 10mm bolt that holds it on.
I'll update once we get time and figure out what is wrong with this car. I have done a fair amount of tuning on the car and it runs very well everywhere else though, and when it happens to not misfire its a monster.
Good to hear you found your problem Sgt Blamo.Itzwolf - We too have changed the CPS and had luck for a bit and then BAM out of no where it started up again. We are going to send the AEM back to have them check it out as the owner wants to eliminate all possibilities.
Keep us posted!
Good to hear you found your problem Sgt Blamo.Itzwolf - We too have changed the CPS and had luck for a bit and then BAM out of no where it started up again. We are going to send the AEM back to have them check it out as the owner wants to eliminate all possibilities.
Keep us posted!
Also I resurrected a thread about the BBK 75MM Throttle bodies, (linkage, brass buschings, IAC provision) mind posting an update to the questions there? (Dont want to clutter this thread.)
The CPS is about $65 plus tax from the dealer, usually there is 1 in stock.
No on the dealer warranty, I didn't want to waste my time. The car is running incredible, the new tranny w/ the MR 5th gear is great! It's SO nice to drive it with no misfire!
Hope you guys get your cars squared away. keep us posted.
Hope you guys get your cars squared away. keep us posted.
Here is a list of possible reasons of P0300:
1. Bad CPS. Replace it and see if the misfire goes away
2. Check the voltage supply to the CPS from the CPS harness and from the ECU
3. Check your fuel trims. The STFT should be within +/- 20 and LTFT should be between +/- 12.5. Test them @ 2500 rpm.
4. Check the spark plugs and make sure that you have a strong spark. Better yet replace them with new plugs.
5. Check the resistence on the plug wires. Make sure they are below 19 ohms. Better yet replace them with new ones.
6. Disconnect the injector connectors and make sure that the resistence is between 2-3 ohms.
7. Check the harness connection from the injectors to the ECU. Make sure that there are no loose wires or connectors.
9. Check the timing belts for a skipped tooth
10. Check the EGR and see if it is working properly
11. Check the compression and make sure it is up to spec.
12. Replace your injectors if they are bad.
13. Finally, if all else fails replace your ECU.
I suspect that the reason Blamo is getting the misfire is the AEM EMS. Go back to the stokc ECU and it might solve your problem. The ECU can handle the power levels that you are running with ease.
1. Bad CPS. Replace it and see if the misfire goes away
2. Check the voltage supply to the CPS from the CPS harness and from the ECU
3. Check your fuel trims. The STFT should be within +/- 20 and LTFT should be between +/- 12.5. Test them @ 2500 rpm.
4. Check the spark plugs and make sure that you have a strong spark. Better yet replace them with new plugs.
5. Check the resistence on the plug wires. Make sure they are below 19 ohms. Better yet replace them with new ones.
6. Disconnect the injector connectors and make sure that the resistence is between 2-3 ohms.
7. Check the harness connection from the injectors to the ECU. Make sure that there are no loose wires or connectors.
9. Check the timing belts for a skipped tooth
10. Check the EGR and see if it is working properly
11. Check the compression and make sure it is up to spec.
12. Replace your injectors if they are bad.
13. Finally, if all else fails replace your ECU.
I suspect that the reason Blamo is getting the misfire is the AEM EMS. Go back to the stokc ECU and it might solve your problem. The ECU can handle the power levels that you are running with ease.
Call Marco @ :
http://www.billetdesign.com/home.php
That's where I had it done. I've been dealing with him for over a year now, he's a bit hard to get in touch with but I fully trust his workmanship. I love how smooth it shifts and the MR 5th gear swap is great. The only thing I would possibly do differently would be to swap in a Evo IX 1st & 2nd gear, keeping the VIII 3rd & 4th, but still adding the 5th gear out of an MR.
http://www.billetdesign.com/home.php
That's where I had it done. I've been dealing with him for over a year now, he's a bit hard to get in touch with but I fully trust his workmanship. I love how smooth it shifts and the MR 5th gear swap is great. The only thing I would possibly do differently would be to swap in a Evo IX 1st & 2nd gear, keeping the VIII 3rd & 4th, but still adding the 5th gear out of an MR.
UPDATE!
If you've had issues with strange misfiring, especially if it occurs once the engine gets hot(not overheated) and you've replaced the CPS w/ no results, then you may want to check the CPS factory plug and/or harness. I had this strange problem occur only after the car would reach normal temps, it would start to bog below 4500 rpms, if I revved it it would be fine. To make a long story short, i found the source to be my CPS (cam position sensor) plug and/or harness, as soon as I wrapped some electrical tape around the plug as it plugs into the CPS, the problem disappeared completely for the past 5 days now with all sorts of different driving conditions. I hope this info may be of some use.
If you've had issues with strange misfiring, especially if it occurs once the engine gets hot(not overheated) and you've replaced the CPS w/ no results, then you may want to check the CPS factory plug and/or harness. I had this strange problem occur only after the car would reach normal temps, it would start to bog below 4500 rpms, if I revved it it would be fine. To make a long story short, i found the source to be my CPS (cam position sensor) plug and/or harness, as soon as I wrapped some electrical tape around the plug as it plugs into the CPS, the problem disappeared completely for the past 5 days now with all sorts of different driving conditions. I hope this info may be of some use.
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