jethrobodean

I need to change the sig. I am currently trying to shake the car down running the stock 24's to make sure everything is working then I am going to get the tune done by madz28 where we email back and forth info until we get it right. I have a week to tune and I didnt want any major problems that would have to be fixed in a hurry.

jethrobodean

Yes it has a MAF. It was descreend by the PO

Injuneer

And it will run on the MAF. But if the MAF dies, the PCM will default to speed-density. If it has the wrong displacement and VE tables that are way off, it won't be able to calculate the mass air flow, and it will fuel the engine incorrectly.

jethrobodean

Ty injun for the explaination. I plan on checking fuel pressure tonight and its good I am going to have to check the cam alingment somehow. Maybe a magnetic dial indicator and piston stop in the spark plug hole and measure the lift to see if both valves are closed at TDC?

I pullled the 1 and 3 plug because of ease of removal and took pictures that I will post later. They didnt look lean. They had a nice toast (yellow/brown) look building up on the arches.

jethrobodean

fuel pressure 38# w/vac 45-46 w/o New reg or fuel pump or both?

Injuneer

Neither..... that is within spec. 42-47psi with no vacuum (43.5psi preferred), and the pressure will drop in proportion to intake manifold vacuum when you reattach the vacuum line. A 7-8psi drop would not be unusual with a small cam.

Dave C. '97 Z28

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fuel pressure 38# w/vac 45-46 w/o New reg or fuel pump or both?
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That's about what it's supposed to be.

Check to make sure the cats or muffler isn't plugged up like a previous poster said. As well, another thing to check is make sure your header (or exhaust manifold) gaskets are sealing properly. If they're loose the exiting exhaust can draw oxygen in and cause heating.

Another thing is that maybe the car is not going into closed loop due to the CPS code or something, which would cause it to stay on SD mode. In this mode, the computer would not be able to compensate as easily for the non-stock parts.

jethrobodean

I will take a look at the headers tonight. I have a new Cps coming tonight so I will see if that helps. I have made contact with the tuner and setting up a tune. I appreciate all the help. Would you guys recommend running the stock TB or the 58?

ACE1252

I see no need for the 58 right now. Don't use it, unless you already have it.

ACE1252

Here is the underside of my 1996 Z28. I still have the stock exhaust manifolds and stock y-pipe on it. From the end of the y-pipe back is a catback system.

jethrobodean

The new CPS did not fix the P0336 code. Upon further investigation it will cherry the manifolds while idling. Hopefully the tune will find and correct the problem

96capricemgr

A bone stock motor benefits greatly from tuning. A modified motor should not be run atall on a stock tune.

I know the injector thing was already covered but just to make this absolutely clear if you put 30lbs injectors on with the stock 24lbs tuning you will likely wash the cylinders down destroying ring seal then if you keep going you will wash out the bearings.

You have done everything so badly to this point you need to stop running the car and start understanding things before you break it again.

Not trying to be a jerk just trying to make a point that you are at serious risk of doing damage if you continue as you have to this point.

MikeGyver

If your manifolds are glowing usually it's because the timing is retarded too far. What is it at? some electrical failures will drop timing to zero degrees and the manifolds will obviously light up.

purple 95 z28

The second one is right below the manifold. You can see it in the top right of the picture.

ACE1252

Yep. It hangs right on the drivers side exhaust manifold.