Injector Help

[vettn71]

Just installed new injecto0rs and coild today. Everything went like butter - no leaks, no issues going together. The car now has a miss from startup. Idles rough, it says I have full power, but I don't, can hear the flywheel hitting - not hard, but sounds like a click more than a bang. All vacuum hoses are in place. Took it out to see if it would work through it - no chance. Didn't get any better. Didn't seem to get any worse, either. No codes are set, BTW.
:dontknow:
Okay fuel injector replacement gurus, grasshopper needs to sit at your knee.

Jim

[GregCrowe]

What kind of coils did you install?

[jonszr1]

also did you do a pressure test after the install just to ck everything?????

[bobbyhi]

I would say that one or more of the injectors aren't seated correctly.

[vettn71]

The coild are GM "545"s From JeffVette. The car ran great when it was cold, but had a hard miss after heat soaking. I thought it would be a coil breaking down with temoerature or an injector failing, so I replaced them both. Did not do a pressure test. I've had no issues with that previously and ran the car two days ago - cold, ran great; after heat soaking, like poop. New fuel pumps and filter, anyways.

Can you explain exactly what you mean by an injector not being seated correctly. I checked them over both in the fuel rail and after the install. They looked sqaure in the holes.

Jim

[secondchance]

What kind of injectors?

[-=Jeff=-]

What kind of injectors?

Yeah I agree.. you might have a leaker..

[vettn71]

The injectors are FICs from Jon

[secondchance]

Based on my personal experience and past posts, it seems both bad coil and injectors going bad, at times seem ok until they become heat soaked.

Do you have access to a scanner?
I am not one of the gurus here but when scanned there is a value, integrator and block learn (I think should be between 128-131?) for both banks. If less, typical suspect is one or more injector failure.

http://www.zr1netregistry.com/forum/showthread.php?t=896&highlight=injector

[secondchance]

Hey, Jeffvette

How did you isolate which injector specifically was the leaker?

[Jeffvette]

Well, one way to go about it (Since these are supposed to be good injectors) first verify that you are getting a leaking condition. Use a fuel pressure gauge and see what kind of drop you get.

Second, pull spark plugs, look for the one that is washed down and smells like fuel.

Or pull the plenum, pull the rail out and lay down a bunch of rags and prime the system and look for the wet spot. :D

[secondchance]

Well, one way to go about it (Since these are supposed to be good injectors) first verify that you are getting a leaking condition. Use a fuel pressure gauge and see what kind of drop you get.

Second, pull spark plugs, look for the one that is washed down and smells like fuel.

Or pull the plenum, pull the rail out and lay down a bunch of rags and prime the system and look for the wet spot. :D

Sorry! I meant to ask =Jeff= since he went through this recently.
Since you answered, Jeffvette, I guess removing both fuel rails, bolting up both rails to fuel regulator and turning the key to on position should pressurize fuel rails and leaker would drip fuel, right? Obviously towels under the injectors to catch leaking fuel to avoid stain on our precious LT5.:mrgreen:

[Kb7tif]

Yeah I agree.. you might have a leaker..


Well, I have the Stock Injectors still in there and i know when I checked the plugs that I have 1 leaker, but the car runs fine cold or hot. So Im leaving well enough alone for the time being, saving the new injectors for a Porting type of overhaul.

[tomtom72]

The injectors are FICs from Jon
Jim,
This maybe out in left field....but didn't FIC have a recall recently on our 1* injectors???? I think the issue was that they got some bad overhaul parts from a supplier??? I don't remember which parts were bad, sorry. I would call Jon, as he is a stand up guy and his customer service is first class, to inquire as to the issue(s).

I assume the "not seated properly" refers to the top's & bottom's of the injectors, usually that yields a vacuum leak & an elevated idle due to extra air getting into the intake system. You say that you have a miss at idle now? That's not a symptom of a vacuum leak though. Your issue sounds like it has an electrical cause to me as it gets worse as the coolant temp come up(?). That could be an ignition coil or and injector coil. I would ohm out the injectors hot as per Marc Haibeck's instructions thru the ECM wiring at his site. Then IO'd check for spark, if not intense I would ohm out the coils thru the plug wires. I would think those readings would be good enough for diagnostics in this case. If I'm missing your descriptive point, and the miss is constant and temp has no affect on it then I would suspect that there is a need to at least pull plugs to see if a rich or a lean condition exists and how many cylinders are affected. That may give you a direction to continue the diagnostics. JMHO:redface:

:cheers:
Tom

[vettn71]

Just talked to Jon at FIC this morning. The injectors I have are new Bosch, not rebuilds. Jon recommended pulling the fuel rail/injector assembly and turning on the key. I did have one primary that leaked a drop of fuel. Jon said that sometimes trash in the fuel rail gets dislodged and can cause an injector to leak. He is sending four primary and four secondary, just to be certain.

BTW, great guy. Really helped me out. I just remember what my dear old Dad would tell me - "If it's got tits or tires your going to have problems with it".

Jim

[tomtom72]

:sign10: I like your Dad's thinking!!!

I hope it is just some trash. Sometimes working on cars can be a very frustrating thing for back yard guys like me. I always think...."well if I would have left it alone...." :dontknow:

Let us know how it turns out, and good luck with the fix!:thumbsup:

[Jeffvette]

Jon said that sometimes trash in the fuel rail gets dislodged and can cause an injector to leak.


In all of my injector changes, I have never ever had something like that happen. Drop injectors in and go. Doesn't matter if it has been GM, Accel or RC.

[-=Jeff=-]

Or pull the plenum, pull the rail out and lay down a bunch of rags and prime the system and look for the wet spot. :D

Yep that is how I narrowed it down

[Ccmano]

I've been putting off trying not to state the obvious because the guys at FIC try so hard to make things right. But am I the only one noticing that virtually all the recent problems with "new" injectors have been with theirs? I put in Accel's last year and had no problems. Seems many folks trying these Bosch injectors have reported issues at first. Issues are ultimately being resolved, but installing injectors should not be this big a deal.
H
:cheers:

[-=Jeff=-]

I've been putting off trying not to state the obvious because the guys at FIC try so hard to make things right. But am I the only one noticing that virtually all the recent problems with "new" injectors have been with theirs? I put in Accel's last year and had no problems. Seems many folks trying these Bosch injectors have reported issues at first. Issues are ultimately being resolved, but installing injectors should not be this big a deal.
H
:cheers:

Yes and you get what you pay for.. I did not pay anywhere near you the accels cost.. if I had the extra $$ to burn when I bought the FICs I would have bought Accel or RC but I personally did not.. car is running fine now for me

[vettn71]

One thing to keep in mind is that my 90 is a NCRS car. I need something that looks stock or wind upo losing points. Jon's been working with me on this and this is the first time he's tried these particular injectors. I'll work it some to get what I want. If it was a street car it wouldn't make any difference. BTW, thanks to everyone who's responded. I appreciate the ideas and assistance.

JIm

[Jeffvette]

Yes and you get what you pay for.. I did not pay anywhere near you the accels cost.. if I had the extra $$ to burn when I bought the FICs I would have bought Accel or RC but I personally did not.. car is running fine now for me


What is your time worth of pulling the plenum once to install the injectors, and to troubleshoot an issue, then to pull it a second time to fix an issue that should have been solved with a good set of injectors?

[-=Jeff=-]

What is your time worth of pulling the plenum once to install the injectors, and to troubleshoot an issue, then to pull it a second time to fix an issue that should have been solved with a good set of injectors?

True, but according to my wife, it was the better way to go..

Now if the injectors go bad in a year, I will probably switch

[Zr1 Destroyer]

Yep...x2! The FICs were a snap......it took me about two minutes to modify my four injector rail mounts and they worked fine from the word go.

[Jeffvette]

The reason more people have problems with FIC injectors is more people bought these then all the other brands combined.

Doubtful.

[Ccmano]

It's not that every set of FIC injectors has one or two with a problem, many people are satisfied. Especially with the apparently excellent service that they provide. However it appears that in an effort to provide an inexpensive injector alternative their quality control is lacking. At $349 a set they have a signifcant price advantage over Accels, at about $510, and RC's in the $750 range. They could easily enhance their quality control, even if it added another $25 to the cost, and still have the cost advantage. Just imagine how many they could sell if they had a flawless reputation!
H
:cheers:

[secondchance]

Yes and you get what you pay for.. I did not pay anywhere near you the accels cost.. if I had the extra $$ to burn when I bought the FICs I would have bought Accel or RC but I personally did not.. car is running fine now for me

My first choice would have been RC also. I did not want to spend $1,500 to find injectors could not fix the problem.

To be fair, call me lucky, my set from Jon worked fine with no issue. At less then 1/4, I will go with FIC again unless I win a Lotto.

[vettn71]

As an update, I did find a leaky injector. Talked to Jon today and he is having a set of Delphi injectors made up to fit the 90 Z. I know pulling the plenum if a PIA, but, being married, I've done a lot worse. First pull took my 4 hours. Second pull, about thirty minutes, so it's not crushing me. My car being an NCRS car (yes, I know how anal I am) it's important that I have original looks and function. Jon's been great working with me. If I need to be the guinea pig to help others out, I guess I'll just oink - or squeel or whatever guinea pigs do. I should have a set by about the end of the week and I'll post how it goes.

Jim

[jonszr1]

i have 2 sets of jon injectors and they are great