hey all,

i am having a blast trying to get my damn car put back in full running order. the idle sucks, slight hunting and some skips. i crank on the throttle and it sounds beautiful and works well.

i think i am dealing with a bad injector(s)... i have a fuel gauge on and after shutdown i am loosing a few psi a second.. full bleed down of fuel pressure in less than 1.5 minutes. is there any way to see which injector it is without pulling the whole thing apart again?

thanks all, you rock

Jason

ps. current mods are: edelbrock runners and intake (ported, gasket matched) holley afpr, accel fuel gauge, new tps, iac, coolant temp sensor, new vacuum lines, new vacuum check valve, pcv, o2 sensor.

 

Definitely sounds like a leaking injector. It could also be a leaking fuel pressure regulator, but since you mention that you've replaced it with a holley unit, you can probably rule that out. Still, it might not hurt to see if fuel is coming out of the vacuum line to it. I can't think of any sure-fire way to figure out which injector it is, but you might try listening to them, and looking for a quiet one. If one of them is gunked up, it might not click as loud as the others. Get a long screwdriver, and with the engine running, put the handle to your ear, and the tip to each injector. You should hear a distinct clicking sound from each one. It could also be the cold start injector, which you won't be able to hear when the engine is running.

Or, if you pull the plenum and runners off, you might be able to test which one it is. You'll have to reconnect the cold start injector to the fuel rail to do this. After the engine has sat for a while, and any fuel in the lower intake has dried out, turn the key forward and let the fuel pump prime. Then, try sticking a paper towel down each runner in the lower intake, and see if one is wet inside. Or, if the cold start injector is leaking, that should be visible.

 

i will give that a shot... i will check on the 9th injector first... pop one bolt and i can swing that up and check on it.

if that is the bad one, what is the easiest way to shut it down? I already have a chip burned to take it out of the startup, just need to install it. would crushing the fuel feed line to it be sufficient you think?


also, to test the possibility of the afpr leaking, i could just unplug the vacuum line to it immediately after shutting down... it will simply run out of that line i assume? (its been on the car less than 3 weeks... i can't imagine its bad but weirder crap has happened to me)

 

It would probably be better to remove the cold start injector line from the fuel rail, and plug it up. I'm not sure what size thread it is, but I imagine you could find a brass plug or something to cap it off. And to test the fuel pressure regulator, yes, just onhook the vacuum line, prime the system, and see if any fuel comes out.

 

did that... no fuel as expected. holley's reputation for good stuff has been upheld.. i unplugged one of my big vacuum lines (to the booster) and listened as i turned the key on. i could hear a couple of the injectors spraying out.

i did some research today, and spoke with John at Fuel Injector Connection. apparently the design of these original injectors is problematic after 100k, and the fact that i left them out of the car for about 4 weeks is what screwed me. he and one other injector repair place told me that they typically do fuse or get really rough running if you leave them out dry for any extended length of time. apparently the trick is to take your injectors out, and if they will be out for a while put them in a can of gas to keep everything clean and uncoroded. John hooked me up with a set of bosche type III injectors (rebuilt with a 3 year warranty) for under 170 for all 8.

i will block off the 9th injector port on the fuel rail; i may just modify the cap itself to seal in the fuel... mayhap fill it in with JB weld or an epoxy of some sort. can i use the 9th injector keep the system sealed, or is there an easy way to plug that hole in the runners? i'm leaning towards free, cheap or easily fabbed.. i've dropped alot of money on this beast, and need all the cheap fixes i can pull off.

 

John was def a big help.I relpied in the other thread.I would recomend gm orings the blue ones.You will understand why once you put them in the rail and manifold.I got my injectors a little cheaper through him.I only paid 125 for mine.He must have went up on his price.But it also may have been I bought 2 sets from him.You will be happy with them after they are in I have been so far.

 

You can just unplug the connector to the cold start injector and that will disable it.

 

probably due to my only buying one set... he gave them to me at 150 plus shipping. he was VERY helpfull... pointed me to the youtube video that he did on all the different injector types. if you are curious, here's the link:
http://youtube.com/watch?v=Emnax2J4FX4

IrocZ28... I am fairly certain thats one of the injectors thats stuck open... which concerns me that it might bleed through backwards if i use it as a plug. u figure if I squirt some epoxy into the body of the injector, that will seal it good enough to not have to worry about it blowing fuel out the back?

 

It will be disabled, but it can still leak fuel that way. If it's disabled in the ECM, it's better to remove it completely.

 

Yes it is better to completely remove it, but I don't think it will make too much of a problem, if any at all, if it is just disconnected.

 

wow that video was very helpfull. I saw it last week. I think i will get rid of the accels in my wifes 92 camaro her multecs burnt out at 96,000 and put in those design 3 bosch's I noticed the spray pattern is a lot better.. maybe i will get better mileage.. any comments on that.

 

thats the theory... the type III injectors are reported to increase your fuel efficiency. i will let u know when I get a few tanks through mine.