Ignition and detonation problems
03-11-06, 08:52 PM
#1
Savanna Rx-7
Thread Starter
Ignition and detonation problems
Still in the process of sorting out my 13bt swap, and seem to have run into some possible timing issues: it seems that my timing is somehow off, even though the marks are lined up properly
I get horrible detonation when I go into boost, the engine is a S-5 with the front end plate swapped to the S-6 version (bigger front thrust bearings) and an S3 front cover.
Currently I am useing the S3 front pulley and it just hit me the timing marks MIGHT be different between the two, (S3 vs S5) anybody know if they are different? this might explain why I am getting the detonation when I boost....
currently I have a PFC hooked up and the computer settings for the timing are very conservative but I still get detonation, when I remove the trailing plug wires the detonation drops down to almost nothing (one line on the pfc) and you would not notice it except for the guage
car is S-3 with the following setup: engine S-5 stock ports, stock turbine, catback FMIC stock injectors with the fuel pump from a 3 rotor cosmo mounted intank, fuel pressure is fine at idle and I am getting ready to check it while driving. ECU is PFC base maps are stock, and I have since retarded the timing in an attempt to get rid of the detonation.
kenn
I get horrible detonation when I go into boost, the engine is a S-5 with the front end plate swapped to the S-6 version (bigger front thrust bearings) and an S3 front cover.
Currently I am useing the S3 front pulley and it just hit me the timing marks MIGHT be different between the two, (S3 vs S5) anybody know if they are different? this might explain why I am getting the detonation when I boost....
currently I have a PFC hooked up and the computer settings for the timing are very conservative but I still get detonation, when I remove the trailing plug wires the detonation drops down to almost nothing (one line on the pfc) and you would not notice it except for the guage
car is S-3 with the following setup: engine S-5 stock ports, stock turbine, catback FMIC stock injectors with the fuel pump from a 3 rotor cosmo mounted intank, fuel pressure is fine at idle and I am getting ready to check it while driving. ECU is PFC base maps are stock, and I have since retarded the timing in an attempt to get rid of the detonation.
kenn
03-12-06, 06:56 PM
#4
Savanna Rx-7
Thread Starter
Originally Posted by RETed
Confirmed with a timing gun?
-Ted
-Ted
Yes I checked it with a timing light, and the power FC says 20 and 5 for the "idle" timing also so computer and timing ight agree. thats why I thought it might be the front pulley.
Tech,
the trailing timing will generally introduce detonation earlier (from being advanced to far) than the leading ignition assuming all else is equal. and like I said I removed the trailing, and the detonation all but dissapears, I am at a bit of a loss at this point the only thing left (ignition wise) is the pulley.
another forum member pmed me with the opinion that if my secondary injectors were not coming on line properly that the lack of fuel could be casueing the detonation.... but I would think that that would be present regardless of the presence (or lack off) trailing ignition ????
he said that the engine didn't make enough power without the trailing hooked up to require the extra fuel from the secondaries hence the lack of detonation when they were removed. any ideas???
kenn
03-13-06, 04:28 AM
#6
Lives on the Forum
Originally Posted by kenn_chan
Yes I checked it with a timing light, and the power FC says 20 and 5 for the "idle" timing also so computer and timing ight agree. thats why I thought it might be the front pulley.
-Ted
03-13-06, 07:08 AM
#7
HAILERS
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A S3 timing mark is at TDC for the lead mark, if it came off a carb model.
S3 meaning the first generation????? Then if it was a first gen carb model, the pulley won't bolt up because one of the four attach holes would be *off* and not align..............unless some *adjustment*was made by you to make it align.
S3 meaning the first generation????? Then if it was a first gen carb model, the pulley won't bolt up because one of the four attach holes would be *off* and not align..............unless some *adjustment*was made by you to make it align.
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03-13-06, 05:45 PM
#8
Savanna Rx-7
Thread Starter
Originally Posted by HAILERS
A S3 timing mark is at TDC for the lead mark, if it came off a carb model.
S3 meaning the first generation????? Then if it was a first gen carb model, the pulley won't bolt up because one of the four attach holes would be *off* and not align..............unless some *adjustment*was made by you to make it align.
S3 meaning the first generation????? Then if it was a first gen carb model, the pulley won't bolt up because one of the four attach holes would be *off* and not align..............unless some *adjustment*was made by you to make it align.
Yes itsa first gen, but the car was originally a 12a turbo (I live in japan) so the stock 12at was a curious blend of n/a and turbo technology, kind of a mix between the S-3 GSL-SE and a S-4 FC
Ted, the timing marks move when reved I don't remember which direction they went but they did move.
kenn
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