got a 91 z 5.0 tpi ,new ford 30 injectors,intake gasket,fuel pump,tps,coolant temp sensor,new plugs,new distributor,no cat. car has a surging idle,and bucks under light acceleration and on cruise,if so one knows the problem let me know it will set code 45 on the highway.

 

Did you get a new chip burned to compensate for the 11 pound increase for the injectors? (I think 305's had 19lb injectors), or check your TPS voltage (.54v), maybe even something simple like a vacuum leak

 

I have 30# injectors on my 6.4Liter and their more than enough for my application.
Why did you use them on a 5Liter and as asked did you update the programming?

 

dude, too heavy on the injectors

go back to the stock 19s unless you have a blower or somthing

 

I think the Ford injectors are rated @ a higher PSI, so they aren't actually flowing 30lbs/hr. But, I would think there is still a big difference in flow between the stock 19's and whatever the Fords are flowing. Just like everyone else has been asking: Did you get a chip programmed to account for the new injector flow rate?

 

Holy crap,IIRC Lingenfelter ran a 400hp 355 with 19lb injectors. 30lb in a 305 is way over kill.. code 45 is running rich at the 02 sensor

 

car ran the same with stock injecotrs except no code but then again it never ran well/long.if i could figure out why on take off and at cruise this thing jerks around like it did before i changed everything i might enjoy this car and not want to part it if you dive it like you stole it this 5.0 is impressive but if you try to drive normal it acts like you don't know how to drive a stick.as far as tuning i threw a hypertech chip in and it was no differerent

 

You would need a custom chip, one that is specifically programmed for the new injector flow rate. AFAIK Hypertech just changes fan turn on temp (so you can run a lower t. stat) and maybe some slightly different timing...

 

wow, stock 305 injectors are 19lb, and ford injectors actually flow more than specified, like getting ford 19lb injectors is like getting 22lb bosch injectors. anyways i know your over fueling it. also check your TPS sensor, that usually makes the car act wierd while driving

 

Yeah, I was wondering if I got it backwards... Thanks for the clarification.

 

i got him the injectors, they are 24lb

 

they would still need a custom chip though

 

I probably bucks at low speed from too much base timing.
What is it set at? benny

 

6 Degree's

 

Ok, it isn't the timing. I hope you get it sorted out. benny

 

You replaced the TPS. That is the only thing stated that has a variable. When you work on something and it does not work after, go back to the last thing you worked on. Recal the TPS.

 

I was finally able to eliminate my surge by removing a lot of timing and a lot of fuel through programming.
24lb over 19lb injectors is too much for the ecm to compensate for. The ECM can only handle 10% not 20% without reprogramming.

 

Back off the fuel pressure at the regulator

 

replace injectors with 19lbs that seems to cured all problems except i think i may have a crappy plug wire as i have a slight surge part throttle so new wires and this car should be ready to go to a new home