I have a '89 fire bird formula with a TBI 350ci rebuilt 75,000 miles ago. After years of running perfectly it's starting to give me a problem.
it's perfect on start up and idle (no problem 0-6500 rpm) but in drive (OD) when I attempt to push the gas pedal more than 1/2 way it chokes out and dies. For years i could "stomp on it" from a dead stop and it would throw me back into my seat no problem from 1st - 4th gear smooth and powerfully. I wish I were more experienced in TBI, so now i'm lost. I've tried running "SeaFoam" through the vacuum hose on the brake booster to clean the injectors, but that didn't work for my problem. Most likely because I don't know if I should troubleshoot it like it's an injected or carbureted engine. Any help would be greatly appreciated. *Photo's Attached*

 

https://www.facebook.com/photo.php?f...type=3&theater

 

start with checking your fuel pressure, the camaro's and firebirds never came with a L05 did you put in larger 55 #hr injectors when you did the swap.

 

Sea foam being sucked up through a vacuum hose does not clean injectors. You need one of these.

 

well i bought the car after the swap so im not sure what kind of injectors (all two of them) the car is running. Due to the excellent fuel response the car has had, i've never had a reason to investigate. and the install of the motor was excellent so it never raised any eyebrows. how do i check the size and serviceability of the two injectors?

 

You can hook up a timing light on the number one cylinder and with the air cleaner off run the car and point the light at the injectors. This will cause a strobe effect where you can see the spray pattern. You want to see a nice conical spray mist , no dripping or half spray.

 

Thats badass, I knew i came to the right place! I'm going to try that now! but does the #1 piston have to be at TDC on the combustion stroke like timing for this to work?

 

you are doing it with the engine running and the timing light will just be a strobe, I still think you need to check your fuel pressure 11-13psi.

 

awesome, when i get the results i will report right back and share the fuel pressure and spray velocity.

 

the vehicle gives code 23- MAT Circuit or IAC sensor(95models)
53- System Over voltage or EGR System or Alt. Out of Range
12- Diag. MODE

 

53 is for vats, 12 is diagnostic mode or no distributer reference , code 23 for the mat is your starting point.

 

if it turns out to be your ecm it should be a service number 1227746 , here is a good deal just double check the service number and swap your eprom into the used ecm.

https://www.thirdgen.org/forums/engi...9-tbi-ecm.html

 

well i changed the MAT sensor and nothing changed, next is to inspect the distributor cap.

 

well believe it or not......... i had a destroyed cap and rotor with a jacked up coil and wire....... so i changed them out after visual insp. and everything is perfect now....thank you for all the help hombres!