Timing randomly being pulled in upper RPMS
Sep 23, 2013, 05:29 PM
#16
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This is a long shot, but the ECU adjusts timing to 5 degrees if it gets the start signal input. Maybe there is some wiring fault/short that causes that input to go "live" at higher rpm due to vibration etc. You could disconnect the pin from the ECU connector as a test and see what happens.
Another possibility would be if the vss is working intermittently and the launch maps are enabled and happen to have 5 degrees in those load cells (I have seen something like this before).
Another possibility would be if the vss is working intermittently and the launch maps are enabled and happen to have 5 degrees in those load cells (I have seen something like this before).
What pin in the ECU should I disconnect? I'll try it out when I get back from Cali on Thursday, as well as replace the knock sensor. The CEL does flash occasionally for knock, usually during spool up or certain part throttle scenarios. The car drives great other than that.
Next thing on the list is to replace the trigger plate. I inspected it after the stock motor blew and it looked fine/flat, but i guess it could still be messed up somehow.
Sep 25, 2013, 04:55 AM
#17
This is interesting as this car did have a UTEC in it at one point in time. I do have a slight rattle in the dash, and the previous owner did a hack job on wiring in the old gauges he put in the dash. I re-did everything when I put the AEM gauges in, but I didn't poke around very much.
What pin in the ECU should I disconnect? I'll try it out when I get back from Cali on Thursday, as well as replace the knock sensor. The CEL does flash occasionally for knock, usually during spool up or certain part throttle scenarios. The car drives great other than that.
Next thing on the list is to replace the trigger plate. I inspected it after the stock motor blew and it looked fine/flat, but i guess it could still be messed up somehow.
What pin in the ECU should I disconnect? I'll try it out when I get back from Cali on Thursday, as well as replace the knock sensor. The CEL does flash occasionally for knock, usually during spool up or certain part throttle scenarios. The car drives great other than that.
Next thing on the list is to replace the trigger plate. I inspected it after the stock motor blew and it looked fine/flat, but i guess it could still be messed up somehow.
Sep 27, 2013, 11:02 AM
#18
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I tore into the dash last night. All the wiring to the ECU is untouched. I did find the rattle in my dash, one of the brass nuts that holds my gauges in place came off the bracket and thats what was rattling. I don't think that would cause the issue however.
The existing wiring that I used when I wired in the AEM gauges is hooked into the harness for the radio as well, so no issues with that that I can see with as its not hacked into the stock harness at all.
Also my ECU is being loosely held in place by 2 zip ties, not sure if thats a bad thing or not. I'm going to put the new knock sensor in but I don't think thats going to fix the issue. I guess next on the list is the trigger plate.
The existing wiring that I used when I wired in the AEM gauges is hooked into the harness for the radio as well, so no issues with that that I can see with as its not hacked into the stock harness at all.
Also my ECU is being loosely held in place by 2 zip ties, not sure if thats a bad thing or not. I'm going to put the new knock sensor in but I don't think thats going to fix the issue. I guess next on the list is the trigger plate.
Nov 13, 2014, 10:33 AM
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Its at stock filter uptop at 20 and the roms set to flash cel at 3 counts low and 6 counts high.
no we haven't tried to jack the filter uptop high to see what it does. i dont think thats going to fix this issue but worth a shot. we will try it then report back. knock voltage is normal no spikes.
i personally think this is something to do with the trigger plate / crank / cam signal.
or maybe bad ground or ignition.
no we haven't tried to jack the filter uptop high to see what it does. i dont think thats going to fix this issue but worth a shot. we will try it then report back. knock voltage is normal no spikes.
i personally think this is something to do with the trigger plate / crank / cam signal.
or maybe bad ground or ignition.
Nov 14, 2014, 07:16 PM
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Thanks for the replies everyone. The issue is sort of fixed. I had the injectors cleaned back in june and the car started making cleaner pulls, the timing is still jumping around from 7/8* to 5* in the 7k rpm range. It doesnt feel like its breaking up but I guess it could be and Im just not noticing it. I ended putting a new trigger plate on as well. I havent checked the tps sensor and Ive thought about adding some more grounds as the car does have a mini battery. Im getting ready to re do the exhaust and do a few more performance related things, Ill add in some ground wires and check out the tps sensor as well and check back in to this thread with the results.
Last edited by sublime44; Nov 14, 2014 at 07:19 PM.
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