So im still workin out the kinks in my 92 RS 305 TBI. So far replaced fuel pump, fuel filter, sparkplugs, removed catalitic and welded on straight pipe in place of it. It idles fine no trouble but when u put it in drive it'll drop rpm's and die. Also when u get it goin u give it gas itll sputter and backfire in the headers. Ant idea's??

I'd like to hear more about this, I've been having the same problem
when I come to a stop in any drive gear it will stall, if I shift to reverse it will stall, and it bucks on the highway.
I have not done a fuel pump yet but I have a feeling it has nothing to do with that

jpstgermain, a possibility could be torque converter lockup is staying engaged which would pretty much be like driving without using the clutch on a manual. Just a suggestion though.

joseph80, what are you working the kinks out after? did you just buy the car and are trying to get it to run, or did you just install an aftermarket part(s) or perform some sort of upgrade?

I just bought it bout 2 weeks ago form a guy who couldnt get it running, ive got it runnin and idleing fine but this here is the main problem im having.

Also its running rich i can smell gas bad when i get on the throttle, thats when its backfiring in the headers

Is there a way to fix the torque converter??

[quote=TZFBird;4324752]jpstgermain, a possibility could be torque converter lockup is staying engaged which would pretty much be like driving without using the clutch on a manual. Just a suggestion though.

Thanks for the suggestion, it does seem like that.
A friend said torque converter lockup back when it was only stalling when in a drive or reverse, the bucking or hesitating is a kind of new problem, would this be another symptom of the torque converter problem?

I'm going to be doing an lt1 swap soon so I guess I'll add torque converter to the list of things to do along with upgrade fuel pump.

Edit: oh, and also its been showing a check engine light on and off, i used a scanner and it says VSS, i bought a vss and it's an electric setup, im wondering if i should install it and see if it helps with some problems, not sure if a VSS problem would come up along side the torque converter stuff

I don't think the converter lockup is your problem. I was just suggesting it to jpstgermain. Well, if you have the ability you may want to borrow/rent one of those scan tools and see if you can check your O2 readings. Maybe that is adding some fuel. I also know that coolant temp (160* thermostat) will dump in a considerable amount of extra fuel. It's ont until you get into PROM burning that you realize just how much a few degrees in temperature makes a big difference on how an engine operates. You could also verify your coolant temp sensors as well as intake air temp sensor. One of those not connected or reading wrong could throw things off. Does the motor die instantly when put in gear, or does it idle a few seconds and then start dying?
If you read through some of the PROM burning guides, the engine will add extra fuel when engine vacuum drops, so if you have a good sized vacuum leak, the ECM could be compensating with fuel and flooding itself as soon as a load is put on it... such as putting it into gear. So, you might want to go looking for a vacuum leak to start.

I'll have to keep thinking as to an explination as far as sputtering and backfire. That may be fixed when you get the idle/ putting it into gear problem solved.

[quote=jpstgermain;4324790]Torque converter lockup is done with a solonoid valve in the transmissions valve body. The solonoid gets a signal from the ECM which uses a speed setpoint to activate converter lockup. Somewhere around 50mph I think. Once the lockup valve is opened I believe it actuates a clutch inside the converter. So, it is quite possible that clutch is not releasing, but not as likely as the valve sticking open however.
You're on your own on the VSS code though. I know it goes from the sensor in the transmission tail housing to the ECM and at some point through a neon yellow box near the ECM. Not sure at what point it goes to the guagepod though. I've got my dash torn apart right now, so if I remember tonight after a few parties I'll look and try to get back to you on that.

I was having this same problem, with my 92, and the problem i had was the guy i bought it from let it sit for 3 years, i would go to drive it and soon as i put it into drive or reverse it would die, or when i came to a stop and left it in drive it would die, the fix was i rebuilt my throttle body and changed plugs wires etc, and it ended up fixing a miss that i didnt know was there, and now she runs perfect.

I have a 90 305 tpi, with a 5 speed that backfires only when my foot is off the gas, it smells of gas when running, and also died 2 times while driving it! I replaced cap, rotor, plugs, wires. I purchased the car in the summer and the guy I bought it from also didnt drive it much, he put 3,000 miles on it in the past 7 years. The car has high milage 170,000. I know that it has a chip and pullies I wonder if that has something to do with it? my check engine also comes on and off. Sounds like the exact same problem. I dont know wtf it is either.

im gonna buy a set of plug wires and a new thermostat and check the vacuum hoses i can find and see if that helps any

does anybody have a diagram of the vacuum hoses for the 305 tbi??

There is a hardline coming out of the side of the manifold that feeds the brake booster. You have lines coming off the front of the throttle body for the EVAP canister as well as PCV valve. If you have cruise, that's probably run off the front as well. On the rear you have a line for the EGR sensor as well as the heater control valve I believe. Off the fitting screwed into the rear of the manifold you should be running the MAP, heater/AC controls in the cabin, and the vacuum reservuior tank that I believe is mounted on the drivers side under the evap canister. I could be wrong about where some of those things in the rear are fed from, but that should be it though. Make sure to check the lines feeding the EGR system good because I had a few breaks in there when I first got the car.

I just wanted to throw this out there since it could help somehow.
Today I was going over spark plug wires making sure they were on tight and in the right order (and they were) then noticed the distributer could be turned by hand.
fixed it, tightened the bolt, and the car has been running perfect, I havent had a chance to drive it much to really test if it has solved the hesitation at highway speeds but it no longer stalls when coming to a stop or shifting to D or R fron P or N.
Check that out, I hope it is that easy for you.
I have a feeling it has been loose the whole time since i bought it and just from shaking and bumps it turned a little at a time till the timing was so far off it didnt want to run well.

does anybody know the size of the vaccum hose right off hand i mite as well just buy a roll and redo it all too make sure

also getting a new set of plugs put on if this rain will quit

done the spark plugs checked the vacuum hose and still same problem

So i talked to acouple of hotrod builders here and both said sounds like my torque converter is bad, they said to try replacing that first then everything else should be easy to figure out