i have a 89 iroc-z28 5-speed. i blew the engine so i put in a 91 350 tpi. after that the car never ran the same. when the car is on all you smell is gas. it idles fine but doesnt have the power it use to have. it shakes alot on 5th gear. i changed the prom chip. what could it be ????????HELP:hail:

 

a little more info on your combo would help ,,,

 

I have heard that if you are using the stock T5 transmission you'll need to replace it soon. The T5 didn't get paired with the 350 from the factory for a reason. It is my understanding that they won't handle the torque.

Also is your setup in good tune? Your cap and rotor are they good? What about your plugs? Wires? What is your timing set at? Was the new engine pressure checked? Theres alot of questions we need answeres to if anyone is going to really be able to help you out.

 

yeah i hear the something about a stock 5 speed will take it for awhile but it will give up alot earlier than normal..

 

The T5 transmission can't handle the power from a 350 TPI, that's why they were never paired together from the factory....

Say bye to that transmission if you drive fast.......

 

If you get a purpose built T-5 it will be fine. Even a stock WC T-5 is ok. The problem was with body rigidity. Under a hard launch with a good clutch the T-top cars would twist up like a pretzel. The hard tops are better, but not by a whole lot.

To answer your problem it sounds like you have a fuel leak somewhere, which would explain the gas smell. I'd hunt that down first. There is probably nothing wrong with your drivetrain. The problem is in the engine. In 5th gear you have a high load low speed condition which brings out a lot of engine problems. The other thing to do is check the timing and make certain it's not extremely retarded.

 

I just wanted to add this to the discussion. I have a 350 in my car mated to a v6 transmission with over 100K miles in it. I don't treat it nice and it's holding up fine. So Yes T-5's will hold up decent. But that's not your problem. Check your fuel pressure and see what you get.

 

HOW WOULD I CHECK TO SEE IF I HAVE AN FUEL LEAK AND HOW CAN I CHECK MY TIMING??????

 

The first thing you should do is get a bottle of degreaser of clean the engine. That way you will be able to see any leaks better. Ok, turn the key to on without starting the car so the fuel pump kicks on and builds pressure. Then I'd start at the fuel rails and around the injectors and do a visual inspection. Then start working your way back along the fuel system to the tank. If you don't see any wet spots or smell any gas(that's going to be the big giveaway) then I'd assume there is no fuel leak. To check your timing you need to go down to sears or autozone or NAPA, whatever you have access to, and buy an inductive timing light and a Hanes manual if you don't already have one. I know they're crap, but it does tell you how to check base timing. You'll have to disconnect a tan wire I believe to disable the electric advance. When I did this I couldn't find a connector(in my younger days) so I cut the wire and put a bullet connector in. After that start the car and let it come up to temperature. Then connect the inductive pickup to the #1 spark plug wire at a place where you won't melt the pickup or any cables. Also be careful not to get any wires near the fan. Point the light at the crank dampener until you see a groove on the dampener. That is your timing mark. Now find the pointer that is located on the timing chain cover. Look to see what the number the groove lines up with. The base timing should be around 8 degrees. The book says set it to zero, but it runs a lot better at 8. If not, you will need to get a distributor hold down wrench and loosen the distributor so you can adjust it. That should fix your problem. If not you might want to look into getting a fuel pressure gauge to make sure the pump is working as it is supposed to. Also make sure all of the plug wires are tight on the distributor and the plugs. You can use the timing light to make sure you're getting spark to all the cylinder by attaching it to each wire. It won't light up if there is no spark. Also pull the plugs and check them to see if an injector is running rich or leaking. If all that fails take it to a shop and tell them to fix it.

 

Forget the fact that the 350 is in place of a 305. It doesn't matter in this situation. Did you transfer your parts over from your engine ? You have the MAF in 89 to speed density in 91.

If you have a check engine light on then you'll need to start there.. Analize the codes... When I first installed my 350 in replace of my 305 it ran rough. I had a knock sensor code. turned out that the 350 knock sensor I had bought was incorrect. Doubtfull that it is the same problem but you changed years, something like that could be incompatable.

also fuel smell.....

You need to verify fuel pressure.. Sounds like fuel pressure could be too high. If it's leaking you outta see it easily. As far as timing goes. you need to disconnect the wire.. Brown with black tracer that pops out of the harness. then check timing.... I think it's around the power booster but I do so many cars in a day that are in diffrent places that I just can't remember for sure without looking.

 

All I have to say is check the dang spark plug wires, i had the same problem. My car would shake like mad in 5 gear, and it smelled, i had a wire not completely connected, check all wires dude

 

Yup, sounds like an ignition problem. Make sure all the wires are connected properly, none swapped (esp. #5 & #7).

Forget all the monkey-spank about the T-5; drive it, enjoy it, and hope it lasts. If driven carefully (no 4000 RPM clutch dumps with slicks, and NO SPEED SHIFTING) it might last a long time.