I have tried searching but don't really know where to begin so if anyone can help me with this it would be great. I have a 95 tbi 350. The motor starts and idles great, if you ease into the throttle in park it revs up fine as well. The problem is if you just give it gas quickly it practically dies and starts sputtering and won't do anything until you let off. The motor came out a truck I already owned and it ran fine in it before the swap which I didn't do. Any help you guys could give me would be wonderful I need this thing to run by friday. It is all factory except none of the o2 censors are hooked up. I have heard that might be it but it seems to simple.

 

Does it stumble when the engine is both hot and cold? O2's are only used when the engine is hot so if it does it when the engine is cold you should suspect something else.

 

just a stab in the dark, but almost sounds like the tps is unhooked. (i have done that before. )

 

Yea it does it the minute you fire it up hot or cold, I will check the tps and see what I find

 

check the vaccum hoses and egr too. Sounds to me like the last guy was right though tps sounds like it would be it. Btw those 02s need hooked up if you would like anything more than poor performance and gas milage (they realy do serve a purpose). Matter in fact metering the fuel is directly related to them which is the biggest difference between efi and carb. Anyways good luck with the problem and hope you fix it for tomorow!

 

Speaking of egr it could also be the other egr( Plugged exhaust).

 

did u put a 350 prom in or do chip work?

 

no like I said it came out of the donor vehicle everything was just swapped over. the thing is it ran great an hour before the swap and now it is awful, I don't see how a sensor could have gone bad that fast. I was wondering if fuel pressure could cause my problem if so I want to check the pump pressure throughout the rpm range but I don't know what pressures are optimal. needless to say it is still not fixed

 

well when it comes to this I am just stupid, I should add this swap went into a jeep so it isn't just a factory chevy I plugged it into, so I can't just hook up the computer and diagnose it that way, that is why I am having so many problems. Everyone I talk to acts like they are stupid without a computer to tell them whats wrong. I dont know how to check the egr for problems. Again sorry for being so stupid when it comes to this motor. I think bottom line it has to be fuel related or so I think. The tps is hooked up though

 

Your are not stupid if you can't see whats going on with the ecm, your just BLIND. FI requires working with the ECM no way around it. You can chase your tail for days and replace every sensor, but if you had a way to scan the ecm you could fix it in couple of hours, or even minutes. Other wise it's just guess and check.

A few things I ran into with FI motors in jeeps (I have a few friends with the swap). First off I assume you don't have a vehicle speed sensor hooked up? That causes problems, mostly with idle. What kind of fuel pump did you use? What is your fuel pressure? Also get your O2 sensor hooked up, that would help things greatly.

 

Well I am going to have the o2 censor hooked up today and get a new sensor, I have been told to get a heated one since it will be behind the collector.

It is running the stock fuel pump but I don't know if there is a pressure regulator on the lines. I may buy a pressure guage so I can monitor that. I was told to keep it around 14 is that correct?

I have a laptop and was wanting to find where I could download the program so I could hook my computer to my ecm and run my own diagnostics on it. Any help here would be great. Thanks for everything so far.

 

http://winaldl.joby.se/

Free software, you can build the cable for 5$, use the schematic at the bottom of the cable page. Or buy one from AKM for 50 somthin.

 

If your car originaly came with a 305 and you swapped in a 350 in its place you will need to use the computer or the prom for the 350 engine otherwise the engine will run lean, also make sure you get your 02 sensor hooked up, not having it hooked up will also cause problems.

 

is any1 Reading this whole thing?

The guy said it ran well enough to his liking before. Now it's not running good at all......

Anyways sorry to say i don't have any answers for you. I just figured i'd save you the hassle of reposting this, so others will hopefully see it.