Revs cut, backfires on 15° normal mode, 20° is ok
Posted: Fri Apr 01, 2022 4:22 am
Hi guys,
Sorry for that weird description
Well, my problem is that I am having issues with the timing and rev cuts around 1.8k-2.5k rpms.
Also, I can’t set the timing marks fine because on diagnose mode, when I put engine in 10°BTDC engine backfires and sounds horrible, if you try to press throttle sounds like knocking and hesitates like engine is not getting any kind of fuel, so I have to set timing on diagnose mode in 15°BTDC on diagnose mode, so in normal mode it’s like 20°BTDC.
I might think there’s a leak somewhere, because idling in quite high for me (1.3k-1.2k rpms) after idling a lot of time and fans were on for a long period. On cold startup sounds like a vacuum over a carpet but after couple of minutes idle goes down and I can barely listen to it. No trouble codes on EFI. TPS sensor changed. Fuel pump were changed like one or two years ago. I tested the pressure on the rail and there’s more pressure idling than the minimun required, when rise the rpms it barely goes up but there’s more pressure that toyota says for full throttle, but in a fast throttling engine sounds like knocking and hesitates for a second and then revs up.
I changed the ignition module (I have 2 old ignition modules) and also swapped the coils. Nothing. I bought a NGK coil for previous Celica 2.0 engine that is like 4age but about 0.5mm narrower and 1cm larger. Nothing. All spark wires were changed and they are new (not original). Distributor cap is new and rotor is new too.
Alternator regulator was changed and outputs 14.5v. Ground and positive wires were improved. The only thing that seems not too good is the battery that is a 60Ah batt when toyota recommends 45Ah batt and I have a battery checker on the battery itself (its a bluetooth module) and seems a bit worm out 54% or so.
What I notice is, when engine is warm up and in operative mode 80°C and above, I have a device that reads values from stock EFI (toyocom) and I can see that when EFI voltage is lower than 13.3v it starts to do that weird rev cut in the range of 1.8k-2.5k rpms.
While driving everything seems fine, but on a traffic light, when I start to drive again I have that annoying problem.
Any ideas?
Thanks in advance!
Regards,
Julio.
Sorry for that weird description
Well, my problem is that I am having issues with the timing and rev cuts around 1.8k-2.5k rpms.
Also, I can’t set the timing marks fine because on diagnose mode, when I put engine in 10°BTDC engine backfires and sounds horrible, if you try to press throttle sounds like knocking and hesitates like engine is not getting any kind of fuel, so I have to set timing on diagnose mode in 15°BTDC on diagnose mode, so in normal mode it’s like 20°BTDC.
I might think there’s a leak somewhere, because idling in quite high for me (1.3k-1.2k rpms) after idling a lot of time and fans were on for a long period. On cold startup sounds like a vacuum over a carpet but after couple of minutes idle goes down and I can barely listen to it. No trouble codes on EFI. TPS sensor changed. Fuel pump were changed like one or two years ago. I tested the pressure on the rail and there’s more pressure idling than the minimun required, when rise the rpms it barely goes up but there’s more pressure that toyota says for full throttle, but in a fast throttling engine sounds like knocking and hesitates for a second and then revs up.
I changed the ignition module (I have 2 old ignition modules) and also swapped the coils. Nothing. I bought a NGK coil for previous Celica 2.0 engine that is like 4age but about 0.5mm narrower and 1cm larger. Nothing. All spark wires were changed and they are new (not original). Distributor cap is new and rotor is new too.
Alternator regulator was changed and outputs 14.5v. Ground and positive wires were improved. The only thing that seems not too good is the battery that is a 60Ah batt when toyota recommends 45Ah batt and I have a battery checker on the battery itself (its a bluetooth module) and seems a bit worm out 54% or so.
What I notice is, when engine is warm up and in operative mode 80°C and above, I have a device that reads values from stock EFI (toyocom) and I can see that when EFI voltage is lower than 13.3v it starts to do that weird rev cut in the range of 1.8k-2.5k rpms.
While driving everything seems fine, but on a traffic light, when I start to drive again I have that annoying problem.
Any ideas?
Thanks in advance!
Regards,
Julio.