Roc THIS

So 4 of my injectors decided to crap out . I am new to this whole TPI thing being used to carbs so bare with me here. Let me start by giving you the story of what happened with the car .

Couple days ago I put headers on the car . It ran flawlessly before hand but now barley starts . I managed to get the car to stay running where I then gave it the only injector test I could think of . I walked around the motor unplugging one injector at a time . If I unplugged a "good" injector , the motor would fall on its face . If I unplugged a "bad" one , then the way it ran did not change . There for making me come to the conclusion that 4 of my injectors are done . Not sure if this is a legit way I could test it but its all I could think of at the time .

So now that my injectors are bad , which ones should I get ? I want the bosch 3's but I was leaning toward 24lb-ers . Because in the very near future this car will be getting alot of bolt ons. Not boosting, just porting to the intake system , cam , heads , and so on . Should I go with the 24's?

One more thing . When I put the headers on , I completely forgot about disconnecting the battery . The engine hoist chain touched the positive terminal on the alternator and grounded the car out . The ignition was off and it only made contact for a few seconds , but could this effect anything ?

Ant help would be great . I want to contact southbay to pick up a set of injectors asap but wanted to run all this past you guys first . Thanks in advance

irocuroc

just call Jon at FIC and get some Bosch 3's
check out the videos on their site www.corvetteinjectors.com

DENN_SHAH

iTrader: (1)

injectors don't normally go bad like that, at least not 4 all at once.
are the 4 bad ones all on the same side of the motor? if they are, check for power to the injectors on that side. there are 2 injector fuses under the dash and you could have popped one of the fuses.

ZimGTA

Also check the injectors with a meter, all the ohm readings should be close to the others.

Roc THIS

Ah fuses ! I never even thought about that . There are 2 on one side and 2 on the other .

Edit : Checked fuse ( I have only 1 for injectors) and its good .

Now should I go with stock 22's or go with the 24lb set ?

irocuroc

just read your OP better.. When the car shorted out and put all that amperage through ground it could have damaged the driver on the ECU. I believe all those injectors fire at once and it has 1 fuse for the injectors. So, it is possible since the ECM is a ground controller that stray voltage with enough amps could have damaged it.. Just a thought. as far as 22 or 24 it depends on the mods. you will need a custom tune for the 24

Roc THIS

I hope it did not damage the ECM but the injectors are original to the car so i think it will not hurt anything to replace them anyways .

Guest

So how do you know they're bad? Just from disconnecting them?

Take off all the connectors, check the resistance of the injectors. Anything below 12 ohms is bad. Its possible you fried the ecm or damaged a ground somewhere, so if they check ok...

24's you'll need to reprogram the chip. Some people run an AFPR and drop the fuel pressure but thats a huge drop to try and fix it. I'd go with the 24's if you can get the chip done cheaply/easily.

Roc THIS

I have never checked the resistance before . Honestly I dont even know how to yet . Guess I will have to figure that out

Guest

There are two terminals in the injector itself, easy to see when you take the connector off. Use a volt/ohm meter and test between the two terminals. Best done warm because some injectors will show as being ok when they're cold but bad when hot. Usually they read about 16 or so.

Roc THIS

Ok I will have to let the car run for a few tomorrow then check again because I just tested them and they all read 16 to 16.1.

Would my ECM possibly being damaged make some injectors work and some not ?

Guest

Not that I know of. There are only four wires, they branch off in pairs of two and then those two are branched off to each bank of injectors.

383tpimachine

easiest way to check if its the injectors or harness is put the working injectors on the non working side. No squirt still and its the ECM

this way you can also see if the 4 "bad" injectors still work

Roc THIS

But the problem with that is there are 2 injectors on each side that dont work.

And the funny thing about this is that my buddy wanted to hear what the exhaust sounded like right off the y pipe before the cat back was not on yet. So I fired it up and it ran perfectly . Few hours later after everything was back on , it could hardly start.

b4ccamaro

Maybe you have a plugged cat. I used FIC for injectors. Jon was great. I will use him again. He has to modify the Bosch 3's to get them to work with TPI. Other shops will tell you to start doubling up o rings. He will treat you right. I just went with 22#.

Roc THIS

That cant be it . For the time being I have no cat.