4K hesitation... more like rev-limiter (I searched)
12-18-11, 06:12 PM
#1
4K hesitation... more like rev-limiter (I searched)
A couple weeks ago I started having the 4k hesitation issue that would cause my car to pop like its rev-limiting.
Since then I have redone all important grounds according to Aaron Cakes website. I have tested all the sensors according to the Fuel and Emissions portion of the FSM and they are all within spec. I rewired the fuel pump to a switch a couple months ago and with that I replaced the fuel filters lo and hi pressure. My actuators are not currently working properly because I have not wired in the RPM switches (S5 intake swapped on S4 block) but I have them wired open at this time. I know the injectors work and flow because I just had them cleaned.
I am out of ideas.
Since then I have redone all important grounds according to Aaron Cakes website. I have tested all the sensors according to the Fuel and Emissions portion of the FSM and they are all within spec. I rewired the fuel pump to a switch a couple months ago and with that I replaced the fuel filters lo and hi pressure. My actuators are not currently working properly because I have not wired in the RPM switches (S5 intake swapped on S4 block) but I have them wired open at this time. I know the injectors work and flow because I just had them cleaned.
I am out of ideas.
12-20-11, 02:14 PM
#4
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If your hearing a hissing then you have the problem I have. Today I gutted one of my cats cuz the insides were all over the place and put it back in and it helped but still not so good so im going to probably gut my other cat and hope its not too unbearably loud.
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12-21-11, 12:18 AM
#10
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"I rewired the fuel pump to a switch a couple months ago"
Is this just a fuel cut switch, or a switch to deliver power directly from the battery?
Is this just a fuel cut switch, or a switch to deliver power directly from the battery?
12-21-11, 11:04 AM
#11
12-23-11, 07:42 AM
#13
Jerd my plugs are fine.
Texas turbo: no dice no blockage
Hozzman: it's the latter so might this be an issue? I've had it like that for almost a year now and it was fine.
Kungfuroy: I did reground the wire to the block. So you are saying you grounded it to the block and it didnt help so you reground to the battery and problem was solved?
Texas turbo: no dice no blockage
Hozzman: it's the latter so might this be an issue? I've had it like that for almost a year now and it was fine.
Kungfuroy: I did reground the wire to the block. So you are saying you grounded it to the block and it didnt help so you reground to the battery and problem was solved?
12-23-11, 07:05 PM
#15
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Jerd my plugs are fine.
Texas turbo: no dice no blockage
Hozzman: it's the latter so might this be an issue? I've had it like that for almost a year now and it was fine.
Kungfuroy: I did reground the wire to the block. So you are saying you grounded it to the block and it didnt help so you reground to the battery and problem was solved?
Texas turbo: no dice no blockage
Hozzman: it's the latter so might this be an issue? I've had it like that for almost a year now and it was fine.
Kungfuroy: I did reground the wire to the block. So you are saying you grounded it to the block and it didnt help so you reground to the battery and problem was solved?
12-24-11, 02:10 PM
#18
So when I reconnected the wire to the fuel pump I remembered why I rewired in the first place. For some reason the fuel pump doesn't get constant power like it should and would randomly lose power and cause me to stop wherever i was be it the freeway or a parking lot. The way I rewired it was to get direct 12V from the battery whenever the switch was activated. I have been meaning to add a relay but hadn't gotten around to it.
12-24-11, 04:27 PM
#19
Wasn't the ECU bought a known good N326 and problem still occurs. I was intending on getting a 2.0 RTEK anyway and the convertibles N338 isn't recommended for the job.
Hozzmans solution is the best bet but unfortunately I do not know why in my particular case my fuel pump loses power intermittently while driving so I don't really feel like pushing my luck with it while testing.
I have also backprobed the secondary injector pins at the ECU (3H,3F) in my case and the main relay power (3I) to determine if the voltage saw a drop around 3800RPM as HAILERS2 suggested in another thread but instead found that they read 24 at idle instead of 12 like they should. I have no idea what this means and have a feeling Im doing something wrong. I have done the load test where you disconnect the pressure sensor and TPS and rev past 3800RPM and determined the secondaries don't fire. it isn't the injectors as I have tried several sets that are known to be good.
Also when resistance testing the injectors the 88FSM states that there should be a reading of 12-16Ohms but mine only read 3.2
Hozzmans solution is the best bet but unfortunately I do not know why in my particular case my fuel pump loses power intermittently while driving so I don't really feel like pushing my luck with it while testing.
I have also backprobed the secondary injector pins at the ECU (3H,3F) in my case and the main relay power (3I) to determine if the voltage saw a drop around 3800RPM as HAILERS2 suggested in another thread but instead found that they read 24 at idle instead of 12 like they should. I have no idea what this means and have a feeling Im doing something wrong. I have done the load test where you disconnect the pressure sensor and TPS and rev past 3800RPM and determined the secondaries don't fire. it isn't the injectors as I have tried several sets that are known to be good.
Also when resistance testing the injectors the 88FSM states that there should be a reading of 12-16Ohms but mine only read 3.2
Last edited by Sgtbaker; 12-24-11 at 04:49 PM.
12-24-11, 09:51 PM
#20
So for anyone that cares it turns out it was my injectors. I had swapped to a pair of Cosmo 720s for a few weeks and during that time soaked my 460cc stocks in acetone to clean them. DO NOT DO THIS!!!!!!!! It ruins the coil windings and causes problems such as my own!!!! When I swapped back to the 720ccs (which I had been correcting as much as safely possible with my SAFC2) I no longer had the problem.
12-24-11, 10:21 PM
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So for anyone that cares it turns out it was my injectors. I had swapped to a pair of Cosmo 720s for a few weeks and during that time soaked my 460cc stocks in acetone to clean them. DO NOT DO THIS!!!!!!!! It ruins the coil windings and causes problems such as my own!!!! When I swapped back to the 720ccs (which I had been correcting as much as safely possible with my SAFC2) I no longer had the problem.
