I recently replaced the 5.0 liter TPI engine on my 1989 GTA with a replacement 5.0 liter long block from GM. A cam and headers were installed at that time. The original intake manifold, runners, plenum, etc was swapped over. I am the original owner of the car which has over 200,000 km on it. I am planning to port the plenum and runners and possibly the intake manifold and heads. I will install a Holley adjustable fuel pressure regulator when this work is done. I have three questions. First, when do fuel injectors wear out? I had to replace one a few years ago with an OEM injector, which was very expensive. Now is the time to consider injectors replacement. Second, can the injectors be replaced without removing the plenum and runners? Which would make my first question redundant. Third, even with the work I am planning I have been advised by several sources to stay with the 19 lb/hr injectors. Do you agree? I am considering Holley injectors due to the good name Holley has in fuel systems. Thanks for you advise in advance.

 

well I aint no expert ...but I will offer this . Your 19lb injectors will be fine for your 305 . If you changed them to a different rate ...without a new prom ....you would be running pig rich . What were the cam specs and stuff ?

 

Send your injectors here.

http://www.cruzinperformance.com/fuelinj.html

 

I had a Comp Cam installed. The gross value lift for the Intake is 0.48 and for the Exhaust it is 0.487. I am considering a PROM upgrade once this work is done.

 

You are going to have to remove the plenium, runners and fuel rail to change the injectors.

 

While your in there, why not do some manifold upgrades!

 

maybe if the lock rings are stuck... i've done it without removing all that. take the fuel rail and lines loose, do the passenger side first, then the driver side. it works.

KAM

 

I have found some companies that will port and polish the throttle body, plenum, runners, manifold and match the gaskets. What other intake manifold upgrades do you suggest? Are you thinking about a new manifold or modifying the original manifold?