AJs91camaro

Hi everyone. I have a few questions about some mods I did with the car and how it is now performing. I had an original 91 rs 5.0 I got from texas. I redid the whole top end of the car. Installed a new summit racing stage 1 intake manifold put the tbi adapter on it, installed 062 vortec heads, new lunati roller cam, new roller lifters, open air filter and headers. Now I just got done installing all theese mods and it starts up and idles ok. When I drive it after about 10 minutes it idles reall bad engine light comes on and it begins surging in the idle. Any information or thoughts would be apreciated.

AJs91camaro

Also since I installed the intake manifold my temperature gauge does not work. I bought and installed a new temperature sending unit still no temp readings

UnderCover89TBI

iTrader: (25)

Ok so the car runs pretty good in open loop. When the vehicle is not being computer controlled. it switches to closed loop and runs bad. you are going to need chip tuning. How big of a cam did you go? This all affects the computer tune. You will need to do extensive computer tuning. www.dynamicefi.com is an ecm you can tune yourself. Otherwise you can buy tuning hardware to burn you own custom chips. or contact tbichips.com and get a custom chip burned. but that option will leave you waiting for chips as it takes several burns to get it properly tuned.

as far as the temperature gauge. you changed the sending unit on the drivers side cylinder head between #1 and #3 cylinders? that is your temp. sending unit. the sensor on the intake manifold is your coolant temperature sensor for the ECM/Computer.

AJs91camaro

my cams lift is .465 and .471. Do you think it could have to do with the EGR? since my intake manifold is non egr could it be running rough because of that?

AJs91camaro

I tried contacting tbi chips for a custom chip and they told me they would not make me a chip for a 305 they only do chips for 350s for customized chips. might have to switch it to carb. This will be a cheaper route I think then trying to get someone that is not racist to 305's. since a vacuum distributor is 50 new on ebay, fuel regulator 100 and carbs are dime a dozen for holleys at 50. I guess what i need to know is whether the problem I have is computer or mechanical somewhere.

UnderCover89TBI

iTrader: (25)

well if the EGR is not burned out of the computer.That would deffinately change things.

In that case you can burn your own chips or use the dynamic efi EBL flash system.

It seems like Brian is getting more and more picky on the stuff he does. He probably just figured it is easier to tell you he doesnt tune 305. he probably doesnt wanna do it.

I am not goign to tell you that you should not go to carb or whatever. It has crossed my mind many times. But a tuned proper tbi will get the same power and more fuel mileage than a carb setup.

A poor running tbi will get the same to worse fuel mileage and not even have close to same performance.