5.7 1987 GTA: I'm posting for a friend.

he changed injectors, now car won't idle at all. What did he do wrong, what could have happened? He says he didn't touch anything else.

The injectors are new aftermarket he bought at a speed shop.

thanks.....

 

Can you provide a little bit more information? What brand? What flow rate? etc.

 

Ok guys they are 24 lb Accel injectors. I will have the car at my place on Monday.

So anybody know if anything else should be changed/adjusted with these injectors?

 

Im not knocking Accel injectors, as I use #36 on my engine. It is my understanding that there has been some quality problems with the Accel #22, #24, #26, injectors. This thread could become a mile long, from members who have had problems with them.

Dont get worried though. Start by getting your fuel pressure to 43 lbs, and work from there. If you install the #24s on a stock, or mildly modified engine, you will have an idle issue. Im sure you can use an AFPR to smooth it out.

 

prom prom prom and oh yeah PROM

 

Did you reprogram the chip? 24lbers flow 10% more than stock, that's pushing it over the top edge end of the ECMs adjustment range.



If the ECM hasn't been updated with the new injector flow rate, the static (no vacuum) fuel pressure would have to be reduced to 37psi so that the flow is at the stock flow rate as a starting point.

squareroot of (Newpsi/43.5psi) x InjectorFlowRate=NewFlowRate
sqrt(37psi/43.5psi) x 24lbs/hr is approximately 22.1lbs/hr

 

Make sure all the injectors are seated properly with no leaks.

 

Thanks guys....I wonder if he should just put his stock ones back in? He had one bad one that was cracked. Maybe just get one new one and call it a day...I don't think he cares about all tat more performance but I'll ask him.

Thanks

 

i just swapped to 24# svo's from 19# 305 injectors on my 350 crate motor, still running the 305 prom (acyd1139). I had to lower the fuel pressure from about 45psi, to about 35psi, cause it idled at 2000. definetly need prom tuning