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2G Where to start? No Crankshaft Sensor!? Stutter? Newbie Help!

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vicks

Probationary Member
12
0
Sep 10, 2017
New York, New_York
Hello Guys!,

I just bought recently a 97 GSX, I am new around here and to the 4G63 realm all together. It has been a very steep learning curve with a new engine and turbo but I am holding on to it and coming up slowly but surely!

So I got a few issues I need to iron out but do not know where to start. I hope I can get some guidance from you guys, it will be totally appreciated. Also how can I figure out what injectors I have, and any other parts I might need to know. Cant tell what size turbo I have or none of that.

These are my issues:

1) When I rev (mostly 2nd gear or higher) above 3.5k rpm the car stutters real badly. RPM and speed keeps going up but the car keep stuttering a lot ( like going up on a cobblestone road) Only happens at 75% or WOT and it happens regardless after 4k rpm.

2) I got CEL! The shop that previous owner used to take it to told me the car only needed a Camshaft sensor after getting one, replacing it and clearing the codes, CEL P0340 keeps popping up. (Is there any special procedures to install a Camshaft Sensor?

3) Now trusting this so specialized performance shop that had worked on this car several time, I had pulled the codes on my own and find out that I am getting P0335 and try to follow the a disconnected cable (after looking at diagrams, pics and vids) down towards the crankshaft sensor, guess what? No Crankshaft sensor wire? Attached a picture to see if you guys could confirm whether I am missing it or not.

4) Having issues downloading the ROM. I took a plunge and even though I am new to all of this I lost my trust on the shop the previous owner took me to, specially after making me wait 4 hours to tell me he would not be able to help me that day and over hearing him having an argument with a customer just because the customer had no updates about his car and it had been weeks of broken promises. That said I bought an openport 1.3u was able to connect and download the ROM but it tells me unknown ROM. I downloaded several Tephra XML definitions to no luck. I can open Tephra ROM but not the one I downloaded.

5) Car does not start up like stock, or right up. It takes a bit of cranking to start up. I changed the IDLE valve Sensor and it did not do much. Any other suggestion?

Pardon if it is a lot of information. I really like the car and Im working on it to get it to a base level before I can embark on the real project for it. I hope this all makes sense as it might or might not sound so newbie but I just did some reading before post as I did not want to come here clueless. Please let me know if you guys would like any additional information that I can provide. I have logged the car and attached the file. Im still learning how to read them. I can understand some, but cant see the how each thing related to another just yet.

Thank you very much in advance, I really do appreciate it.

Here is a pic of the connector without mate
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  • EvoScanDataLog_2017.09.23_13.27.06.csv
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It sounds to me link the car has a 1G CAS installed which would provide both the cam angle and crank angle signals to the ecu.

Also tephra mods would only be used if you have an evo or 3g ecu, it is more likely that you have a blackbox ecu and thus would be using ceddy mods.
http://ceddy.us/ceddymods/

The stuttering you are experiencing is also most likely from using the 1G cas with a 2g ecu. To fix this one you will have to disable misfire detection via the Periphery bits table (292) to disable the P0300 code in ecuflash; using the estimated crank signal from a 1G cas provides a close but slightly different from stock cam to crank timing than an actual crank sensor would provide and this messes with the misfire detection causing the car to cut off 2 cylinders that it believes are misfiring, disabling this with the Periphery bits table should fix it if your are in fact using a 1G cas

If you could post a wider shot of the engine bay with the CAS in view, I can try to help you further diagnose your issues.

Also the wire you are holding is probably the AC switch which would go to the compressor behind the block. It looks like the crank angle sensor connector is the one sitting under the brake fluid reservoir in the picture with one yellow wire coming out of it, which should be going to the CAS if it actually a 1G cas.
 
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Here is a close up of the CAS
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@Spiro2k6 I do not know if I am using a 1G CAS on a 2G. Shine some light, I replace the sensor with the one the shop had told me I needed to get. I had gotten another round one all metal and the guy turn me away telling me it was not the one I need it. After that I order another black top and replaced it myself.

As far as the ROM. So usually is ceddymod regardless of it being a 2g with Evo 8 ECU?
 
@vicks Yes, you have a 1G CAS so not having a physical crank sensor is normal an not an issue. A 2G CAS is not adjustable. 1G CAS' are commonly used when swapping to a cam that is not tapped for a 2G CAS or if a 6bolt motor was swapped in.

Some good information on a 1G CAS in a 2G can be found here: http://www.roadraceengineering.com/1gcasin2g.htm.

For proper installation of a 1G CAS the shop should have locked the ECU timing at 5 degrees BTDC using Evoscan and rotated the CAS until the crank timing mark also reads 5 degrees BTDC with a timing light.

EDIT: i did not see that you are using an evo8 ecu. In that case, it probably is Tepra that you will be using, I do not have any first hand experience with Tephra on an Evo ECU but there should still be a table in ecuflash you can use to disable the misfire trouble code/detection

It also looks as if one of your exhaust manifold studs has been replaced with a bolt. It may be fine as it is if its not leaking any air but you may want to replace it if you ever have the exhaust manifold off.

You also should replace the busted pressure gauge on your fuel pressure regulator so you can verify that your base fuel pressure is set correctly

@vicks Try downloading the "All Evo XML Pack" from the second post on https://www.evolutionm.net/forums/ecuflash/451836-tephramod-v7.html and make sure you change the rommetadata folder in the ecuflash settings to where you extract the xml pack to or copy the xml files to the default rommetadata location. Hopefully one of the xml files will match up to the ROM that is currently on the ecu.
 
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Thanks for the tips Spiro. Ill be reading the links you sent.
I already bought the gage and will be replacing it shortly. I replaced myself the CAS, so I guess I did not do it properly. This is a picture of the ecu that is in the car. When I looked it up it said 2004 Evo VIII
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Ill definitely check that stud out and replace it. As far as the XML pack, I tried with the same pack. Ill try putting the packs in all metadata folder see if that change anything. Any other suggestion on my other issues?
 
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