bigjeepinyj

Well I am about sick and tired of this TPI swap....

Here is what I have:

I swithced a 92 Trans Am TPI onto my older 350 Block...

I have replaced all sensors and have a new wiring harness. The computer is throwingno codes. I hooked it up too a scanner and everything is reading fine.

My Cam Specs:Comp Extreme 4x4 262/270 .462/.480 111 degree lobe sep...
Injectors 28lb. Accel

I am getting extremely low vac. and my MAF sensor is throwing low volts. I cant seem to get more than 14"... My plugs are wet and I have some fine glowing headers.

Any thoughts. I am about ready to throw the stock cam back in there...

92 zzz28

I would venture a guess that your cam is way off for a TPI application. You did not mention any chip tuning or changing so I have to assume you are using the stock chip. It will not promote strong idle vacuum, thus the computer thinks the engine is underload. You said you are using a 92 TA TPI setup, with a MAF!?!?!? What?? If you are using 28# injectors without retuning the chip then you are getting alot of fuel in there. The fuel is just puddling, as shown by the plugs. Your headers are glowing because the fuel is puddling, not burning.

bigjeepinyj

Well I guess I left some things out. To save myself from looking like an idiot. The PROM is reprogrammed and I meant MAP. It was done by Jims performance with all my specs.

Anyone else have any comments on the cam....


Anyone else with some suggestions.

kevinc

What does your timing light show w/ the ESC disconnected?

Bort62

You can forget trying to get that thing to run right with out doing your own chip.

Whats the Duration @ 50 on that thing ? in the 220's ?

As an example, My cam (218/224) on a 110 LSA in a 305 Idles in the ~65 KPA range at idle.

It took me a considerable amount of "adjustment" to get the blms anywhere near right at idle (or anywhere else for that matter)

You are going to have much lower VE"s than stock untill higher RPM's, So the PROM is going to be very rich down low, just like mine was.

bigjeepinyj

First off Thanks alot guys!

KevinC: The timing with the ECS disconnected is about 8-9 deg. It does advance the timing with it plugged in. I have checked and re-checked everything...

Bort62: That is what I was afraid of... Jim told me that it wasnt that big of a deal, but everyone else that I have talked to said that it is has to big of a duration..

Now Bort62 if I put my stock cam back in there and use some new lifters (threw the old ones out...thought that I was set) I assume that I can still use my 28lb. injectors in there if I have the PROM programmed for a stock cam?

I really dont need the cam I was just looking for something different. Well I am going to have to kick the guy in the butt that sold it too me..

Anyone else....

Bort62

Well, Yeah if you do put the stock cam, or even another aftermarket with a tighter LSA and higher low RPM VE's in there, its gonna work better - but it still won't run that great.

But why not save yourself the hassle, and pickup the simple tools needed to burn yourself a few chips.

Not only will you be saving yourself the extra work of the cam swap, but you will gain the ability to actually get the engien tuned right.

And you can benifit from the added power of your cam.

If you can use a Scan Tool, You can do this. It isnt hard, trust me.

bigjeepinyj

Here is the .50 Spec:

218/226 at .050

Bort62

I would not expect that to idle properly in a Speed Density TPI 350 with a stock PROM.

bigjeepinyj

It is not a stock prom.......

Bort62

Right but what I mean is the PROM is not tailored by someone sitting there with your car at hand and observing what changes do what.

Over the counter we can get semi close depending on your combo, but the more differntiated it gets from something we Have experiance with, the farther off it gets.

For example, your cam is pretty similar to mine as far as Duration and LSA.

So I could take my PROM and adjust it for your injectors and cyl size, and it would probrably run o-k.

But It would need the fine tuning to be getting every last Hp out of it that can only be done with the exact car at one's fingertips

bigjeepinyj

Ok,
I am going to be rockcrawling with this. If I could get it to run without burning the motor up I would be happy. I have quite a bit of horsepower for the gears that I have.

I would just like to get something that would run close.

I am out of cash as far as that goes. I have 125 bucks wrapped up in this chip and want to get it right... I know that he will want to keep working with it...

With the cam that I have does 14-15" of vacumm sound about right? He just cant believe that is the vacum...... Thanks alot for all the help this is great.

Bort62

That Vaccum does sound about Right for the cam, Maybe a little on the low side but not rediculous.

If your rock crawling, you want something thats not gonna be coughing and sputtering at low rpms cause its rich and out of tune. Your gonna want a nice smooth torque curve.

for 125 bucks, You could have almost bought a PROM burner

bigjeepinyj

Well he sent me two more chips too try. I guess that I will try them out before I break down and try something on my own.


Anyone ever burn a chip for this exact cam?? (Long Shot) I would give a little for the settings.