hey thirdgeners i am having a problem with my 89rs it came with a 305/700r4 i pulled the tranny n engine n replaced them with a 383 stroker from performance chevy and a 700r4 stage two from b&m . my problem is in the afternoon ride home the car gets up to around 23+ on the gage then all of a suden it starts losing power it chokes and trys to die. i give it some gas and it sputters and blows out black smoke. when i open the top of the stock intake it has some smoke/steam (not too sure )in the tbi unit . i will turn the gas cap and it will spit out gas n vapor for a few seconds. is it a sensor? i had replaced the fuel sending unit and fuel pump last year . i dont know what it is doing, everything under the hood is new exept the stock tbi unit. i know it is a lil small for the new 383 but would this be my problem? i had a bored out 454 tb on it when the motor was put in but it ran so bad i took it off . can anyone help me out? has anyone had this problem in your maro or bird?

 

To start I would check your vent line on the fuel tank, also the charcol canister lines. Your tank shouldn't hold pressure like that.

I am guessing that your 23+ is the tach. If so that sounds like what my car did when the fuel pump went. Eventually it wouldn't start.

Blowing out black smoke would be running rich.
Did you get a tune when you put the 383 in? That could also be a big factor.
Do you have any engine codes?

 

SORRY i ment 230 degrees + and no i didnt get a tune i know it needs one but i just dont understand y i can shred thru traffic most of the time no problems . its a beast , but every once in a while(more latley)it starts acting up. where is the charcol canister? and what does it do? i know i need a new breather filter for the fuel tank it is kind of dirty. do you think that is my prob?

 

When my temps hit 230 it was due to the internal corrosion of original radiator after 20 years. I was second owner at about 5 years prior to failure. A stock aftermarket replacemnt radiator dropped temps about 10 deg overall from my best numbers ever. Being in AZ it would appear you need to replace unit or have it professionally cleaned.

As far as "acting up" does it show a code? I suspect one might be sitting in ECU. Mine threw a code when I modded engine with no tune. code was lean! No reason why you can run stock TBI with 55 or 65 lbs injs. Just need to crank up FP and get a "tune". Granted the stock 305 tbi will restrict intake flow but all that hurts is performance. DIY PROM(stickies) or contact TBIchips.com(Brian) to make it better.

 

I have all new radiator it seems like some kind of cpu or sensor acting up is there a temp sensor for incoming fuel? mabie when a sensor gets to 230 degrees it makes the cpu runn leaner/richer to compensate for fuel temp????????????????