jewbacca

iTrader: (5)

I'm wanting to upgrade my stock injectors to a set of 30#'ers for a planned cam upgrade. This is my second set of supposed 30# SVO injectors. They are the new all plastic thinner type III Bosch. The first set had an orange body. When I swapped them in and reflashed my PCM for the bigger injectors the car ran extremely rough (like it was missing on a cylinder), and was extremely lean (I'm talking around 19:1). They guy I bought them from on ebay let me exchange them for a different set (this time with the red body). After swapping them in I had the same symptoms. My buddy had me swap in my stock injectors and start up the car before reflashing to my PCM back to the old tune (he wanted to see if it was the tune). The car ran great.

Has anyone run the new body style SVO's on an LT1? I have a friend that has a bunch of the older style EV1 SVO injectors he'll sell me. When I sent the first set back to the guy I thought maybe one was bad. He told me he checked them out again (I guess through a tester) and the worked fine.

Catmaigne

iTrader: (6)

I'm pretty sure Ford fuel pressure is lower than our stock 43.5 psi. If those injectors are rated at 30 then they're probably a little higher by a few lbs/hr on a LT1, but nothing crazy. The car wouldn't run crazy rich if the injector constant was slightly off, you would still be able to drive it. Did you change the injector offset in the tune? I ran my set of Bosch III "36lb" white injectors in my car for a little while and didn't change the stock offset tables (but I did change the constant). There was some surge below 2k that could get a little violent with the clutch fully out but it was still driveable.

jewbacca

iTrader: (5)

Yeah, the tune was set for 31.5# (I think) for our cars higher fuel pressure. The car seemed to run just fine (if a tad on the lean side, maybe 15:1) while on the tune for higher flow with the stock injectors. Everything I've read says that these are the same injectors as the old "red tops", just in a thinner plastic body.

What's weird is when I reinstalled my old injectors I could feel them seat when pushing the fuel rail down. I didn't feel the same thing with the new injectors, yet they are both the same length.

Here is a link to what I'm trying to install if that helps: http://www.fiveomotorsport.com/30lb-...ed-devil-bosch

Catmaigne

iTrader: (6)

If the injectors weren't sealing at the intake then they would have enough space to push right out of the rails. If it's not spraying fuel everywhere then I think it's safe to say you don't have a problem with sealing. Some people (mainly 3rd gen owners) have to use 2 o-rings with the Bosch IIIs so they won't push out. I didn't have to with mine (0280155811) but I know of one guy with a LT1 who had to double up.

Either your tune is way off or you have a leaky injector. What sucks is that you can't just pull the rail off and prime to watch for leaks because there are no retainer clips. I would bolt it up to a spare intake (if you have one) and watch for spray.

jewbacca

iTrader: (5)

Yea your injectors use the same body as mine. My buddy had a good idea to use the clips on the extra slot at the bottom of the injector to keep the fuel pressure from pushing it out of the rail. It seemed to work. What's weird is when I installed the new ones I never got the "pop" I got from the old injectors. I'm starting to wonder if the guy sold me bad injectors. I don't think it's the tune since my car ran fine on the new tune with the stock injectors. I've looked over both tunes and the only difference is the injectors. I'm starting to wonder if I should just use my stock injectors with the new cam. It'll be pretty big but I know plenty of guys are making big power on stock injectors.

jewbacca

iTrader: (5)

So I decided to test the injectors a bit. I hooked each one up to a 9 volt battery to at least make sure they all click. Sure enough each one seems to work. That doesn't mean they all flow fine, but I'm at a loss... Anyone have an idea of what to check next?

Catmaigne

iTrader: (6)

You can check the resistance of each with a multimeter. They should all be fairly close to each other. I think mine were all around 12-12.5 ohms.