I just finished swapping a 305 TPI into my 91 RS that originally had a 305 TBI and for some reason it tires to die down when I give it some gas. It seems to idle fine until i hit the gas then it dies down a little bit and idles pretty rough as it slowly gains rpm's. I ran the codes and got a code 22 and a code 42. I already checked the timing and everything so I'm pretty lost as far as what could be causing this. If anyone has any ideas please let me know. Thanks.

 

Fuel pump??? Check your fuel preessure . The TPI may require a different one with higher pressure then the stock one for the TBI.

 

To clear everything up I changed the complete wiring harness, fuel pump, ecu, and everything else i should have. It idles fine till I give it some gas so I doubt it's fuel pressure. It also vibrates while climbing rpm's like the timing's off but I just set the timing yesterday.

 

I would still check the fuel pressure to see what its like under load. It should be 36/38 PSI at idle.

 

Is there anything else you can think of checking and if the fuel pressure is too low what should i do about it? Fuel pressure regulator?

 

You need an adjustable fuel pressure regulator in order to adjust your FP. what injectors are you running and size?

 

If you replaced everything, how about the Fuel pressure regulator if your FP checks low.

 

It's a 305 TPI out of an 88 Iroc that was in a junk yard. I have no clue what is done to it. It runs perfect at idle though and the only codes I'm throwing are ignition. I got code 22 (throttle position sensor) and code 42 (electronic spark timing).

 

I think you just answered your own question..

Try flipping it to WOT from a dead idle and see what happens.

Is your EST wire plugged in? On a stock TPI car, that's a little wire up by the heaterbox that sticks out of the wire loom.

 

I am getting the 42 in my car as well and have yet to figure it out. I have the timing set to stock 6* and the EST wire is plugged in, but I still cant figure it out. Hopefully I can figure something out after I get my Helms Service Manual

 

I just tried to start it again. It's taching up fine now but the timing is off. I thought it was 0 degrees like my tbi was. I just found out it was 6 degrees. I'm going to try that and I'll be back on to let ya know how it went. And that conecter is pluged in. I didn't go completely retarded yet, just really close.

 

Sorry, but it looks like you were retarded....

Did anyone else laugh??

Try 6*..

 

I'm laughing on the inside. I still have to set my timing since there is 4 inches of snow on the ground I'm kinda taking my time. Does anyone have vacum line diagrams? I think there might be a problem at my EGR vacum solenoid. Thanks again and I hope to not be so retarded (or at least my timing) next time I check in here.

 

Of course this can't be easy. I set the timing and everything was fine till I hit the gas. As soon as it reved up the check engine light came on and it started doing the same thing as before.

 

A few mechanics I talked to told me it sounds like a bad computer. Anyone have any other ideas?

 

Of course its the computer! Its not getting correct input from an important sensor!!! How about you diagnose the engine codes, huh? You said you got a code for TPS voltage error. REPLACE THE TPS SENSOR!!! Or like I said, mash the pedal down instead of going slowly.. straight to WOT (after letting it idle a bit first obviously) and see if it tries to die then.

That could be triggering the EST error because the computer doesn't know what to do with timing because it doesn't know where the throttle is at!

 

I just changed the tps last night. I've tried just about everything. And mashing the pedal down is what I do best, but I'm still getting the same problem.

 

Are you still getting the TPS voltage code? Did you set the TPS sensor to the proper voltage at closed throttle (.54-.55v)?

 

I'm still getting the same codes and the same problems. The tps is set correctly and I'm not completely out of ideas. If you have any other ideas or questions since we're both online right now send me a message at Slowmaro91RS. That's my aol name too.

 

I just read something about having to change the fuel lines when doing a TPI swap. Since mine are still original does anyone think that could be the problem or should it still get enough fuel?