Good and Bad day today....

[Ghost_GSX]

So I got my 6-bolt motor in my 96 gst today. Took a few trys and she ran fine. Idle was at 2k but I wasn't too worried at that moment. Took a roll around town and she ran good as far as driving around (spun 1st and sometimes 2nd). Got back home and adjusted the throttle cable on the back of the intake manifold, and now she idles normal but has no go at all. When I rev it in neutral it climbs the rpms really slow.

But I did get it running.

I'm running a stock t-25, Greddy 24v fmic, 1g bov (yes its recirculating), 1g tb, 1g intake minifold, 99 flash-able ecu from my gsx

The worst thing was my starter went out and it was a freebie from a friend so now I have to go buy one.

Can anyone diagnose the problem?

 

[Ghost_GSX]

ok.. lets start over.

1. Check your timing, Barrow or buy a timing light. timing is a very important part. 2g's are 8 deg BTDC
2. You obviously have a boost leak for the 235434 time. Could be multiple things piping to FIAV to the TB needing rebuilt ect ect. This will cause the high idle, throttle problems ect.
3. Your RPM issue 2gs have two places it gets RPM signals, One is the Crank Angle sensor on pin 89. The other is the Ignition Pulse detect signal on pin 58.(ECU PINS) If your RPM is off You can check the cas that has been wired in. It now takes the place of your crank sensor, it may not be shielded.



I really don't know why you have not taken any of the advice given, and keep insisting all who have given advice are wrong. You must know alot more than i do.

Not saying that everyone is giving me wrong advice.
I was looking for something more in dept as you stated. It really gets annoying when all I see is do a BLT and thats it. Nobody stated potential problems that can be found while performing a test.
What do you mean the CAS may not be shielded?
Doesn't the power transistor tie in to the Tachometer somehow?

 

[GSXUAL]

If your boost/vacuum gauge is reading zero at idle, that means you have a vacuum leak or it's installed wrong. That's what the Gauge is for.
Until you rectify THAT issue, I can't help you.
Like I said @ idle you should have 20" of mercury with stock cams. My 272/272's give me 15" of mercury at idle.

You keep saying it's not a boost leak / vacuum leak. If you really have 0" of mercury at idle I would say you have a manifold vacuum/boost leak. Manifold vacuum is after the throttle body that's why I suggested it could be either a manifold gasket or injector o-ring,or even a vacuum hose that's split or popped off.

 

[Ghost_GSX]

If your boost/vacuum gauge is reading zero at idle, that means you have a vacuum leak or it's installed wrong. That's what the Gauge is for.
Until you rectify THAT issue, I can't help you.
Like I said @ idle you should have 20" of mercury with stock cams. My 272/272's give me 15" of mercury at idle.

You keep saying it's not a boost leak / vacuum leak. If you really have 0" of mercury at idle I would say you have a manifold vacuum/boost leak. Manifold vacuum is after the throttle body that's why I suggested it could be either a manifold gasket or injector o-ring,or even a vacuum hose that's split or popped off.

Installed the gauge to P on the TB as VFAQ said to be easiest way. Now I'm reading Vacuum around 18. If I tap the gas it jumps to 0 then falls to 23. And I'm only getting to about 5psi max boost. Yes I can see where everyone is saying boost leak with only getting to 5psi, but I'm spooling up at low rpms according to my Tach (which is reading incorrectly). I would like to know how to fix the Tachometer issue before hand so I can Idle correctly.
All my vacuum lines are brand new.
Just swapped Throttle bodies with new gaskets to see if that may have been it.
New intake manifold gasket.
re-did all my couplers to make sure none were popped off.

 

[GSXUAL]

So the gauge was routed incorrectly? Regardless it now sounds like your in business.
Stock tach or after market.
And your having idle and boost issues?
How is the boost controller routed and are you using a 2g Maf or 1g?

 

[Ghost_GSX]

It was indeed routed incorrectly.
I'm running a stock tach and 2g maf
When I first started the car after dropping the motor in it idled at 2k with the green top. Ran like a champ and pulled like no other. Then after a short ride its went crappy. Now I'm running a black top and still the same.
You can tell by the sound of the engine that the rpms are reading incorrectly. Especially when accelerating.

I have 2 hunches on what may be the problem.
1st (and not typically so sure as it will help or not) is to try a 95 or 96 ecu as I've only ran a 99 and 97. The cars wiring harness was set up for a 6 bolt swap and is a 96 model car, and I remember on here http://magnusmotorsports.com/wp-content/uploads/2010/02/1gina2g.pdf it was talking about moving moving pins around. I have not taken a look at this yet but will shortly.
and 2nd the wiring for the CAS may have shorted out or may be wrong.

I had a friend that keeps trying to point me to my mechanical timing being wrong but like I told him several times that it was perfect TDC#1

 

[counti41]

could be a bad power transistor!!!

 

[97gst_spyder]

The CAS or CAS wiring my be causing the issues. I'd check all the wiring going to it and look for cracks, etc. If that seems ok, test with a known good CAS.

 

[onefast2gdsm]

I have two good 97 cas's if you need one that is for sure good. I understand the 1g cas wiring deletes the crank sensor, as I've done it on my car, but it's just a suggestion

Sent from my PC36100 using Tapatalk

 

[GSXUAL]

So it's a 96'w/99 ecu,and a 1g six bolt?

First things first. Check and double check any wiring necessary to do the swap. That means if there's any crimp conectors or soldered joints make sure to tug at them to make sure they are all tight.Also make sure to pull on the wires coming out of the connectors because sometimes they can break inside the connector. Also while your at it, clean and tighten all chassis, engine and PCM grounds.

If you have a lab scope you can scope the cmp/cas sensor. I also remember on 2gs w/ a six bolt, something about inverting the cmp/cas signal and swapping plug wires. Not to sure on that tho as I run a 1g. Do you know about Any of that?

Before you start throwing parts at this car it's important to start with the basics. Until you've done a proper boost leak test your skipping a rather important diagnostic step.

Don't mean to come off snarky if you thought so. I can understand how frustrating this must be for you.I really am trying to help.gotta admit tho I don't know too much about the 2gs

 

[Ghost_GSX]

Power Transistor is good, as it was my first test to see.
I have a black top and like 3 green top CAS I could probably swap around and test.
I've redone a little bit of the wiring myself due to missing plugs but they are all in order.

According to Magnus, The cam signal is inverted. On 95-96 year ECU cars the injector trigger wires need to be switched to bring signals back into phase. Since I'm running a 99 ecu then I shouldn't worry about it as i assume. Nothing is stated about 97-99 ecu cars.
It also stated that the spark plug wires need to be switched around also. It doesn't state what years it needs to be done to.

My first test today will be to invert the spark plug wires after I check and re-check all the wires necessary. After that I'll start looking more into other things.

Yes I am very frustrated with this and sorry if I came out insulting anyone or doubting anyones knowledge. I mainly haven't done a BLT yet because I don't have any way of testing right now. The local shop here want $80 to do it so I walked out without giving them an answer.

Recent update: Checked the wiring for CAS and everything is kosher there.
Spark plug wire swap didn't work.
Will try swapping out CAS later to see if that may be that.