ok so i have an 88 camaro i bought it a few months ago off a guy that had already swapped a 350 block into it (i checked the casting numbers). My problem is it runs super rich i can smell gas every time I'm sitting at a light and theres a lot of dark smoke from the exhaust and the occasional back fire if i really hit the gas from a dead stop. Now i know the right injectors are in there and the spray pattern looks good (mist not stream or drip). Could he have never changed the ECM? If so what ecm/chip would i have to get i heard or read some where that 88 ECMs are different from other f-body model years.If thats true i'm guessing that the Caprice chip won't help. One last thing the car is straight piped and i don't think the O2 was relocated anywhere was probably just cut at the harness i assume. any help is greatly appreciate thanks guys

First of all, are we talking about TPI or TBI here? Since you said you can see the spray pattern, I'm going to go out on a limb here and say that you're talking about TBI.

Either way, I had a similar situation when I first did my 305-350 swap on my car. In my case it was a TPI setup, but I think some of what I learned may help here. I swapped to the bigger motor, so I also swapped to bigger injectors. When you swap to bigger injectors but don't update the tune with the proper injector constant, it thinks you still have small injectors, so the pulse width of the injector firing winds up being too long, and you get too much fuel. Most likely that's what's happening here. I'm guessing that the previous owner may have swapped a bigger throttle body on there, but didn't update the chip, so now it runs rich. Either that or they tried to compensate for the bigger motor by bumping fuel pressure and they went too far.

I would try to determine what size injectors you have, check your fuel pressure, and also crack open the ECM to see if you still have the stock chip or something different. Once you figure out these 3 things, chances are you'll know what's going on.

it is a TBI sorry i didn't specify. I'll check the fuel pressure as soon as i get a chance but how would i check if it's a stock chip? and would the lack of an O2 sensor cause me any problems like running on "open loop"?

btw i love those rims man

uh... thanks. They're the stock IROC wheels.

To check the chip, pull the computer down (up behind the passenger side dash) and remove the access cover that's held on by 2 screws. If it's an aftermarket chip, it should have either somebody's brand name on it, or an aftermarket socket holding the EPROM.

Not having an O2 sensor will certainly cause you to run open loop and somewhat rich, but not enough to cause black smoke in the exhaust.

really lol? they look bigger for some reason deff bigger then the stock 16's maybe my eyes are just goin lol but i'll check out the chip first chance i get and let you know aha i find. one more question what should the fuel pressure be on a 350 TBI?

I'm no TBI expert, but I think anywhere between 9-12PSI is considered "Good enough" by GM.

ok so it turns out theres a 91 TBI 4.3 S10 computer in there. I'm assuming with the 91 S10 chip.should i try to find a 88 camaro ECM and then do a chip swap or continue using the S10 comp and a chip swap

bump

Do some reading on your truck # 16144288 ECM .It doesn't have a removable chip
http://tbichips.com/ecminfo.htm