fuel system ?????

[jonszr1]

i a m trying to bet to the bottem of a problem with my 90 zr1 . i have one plug that came out medium to dark brown . all the others are wwhite as they allways have been . did the key on test and the pressure went to 43 andthen snapped to 38 where it stay for a couple of minutes then started to go down . the pressure seemed low though well today i finally got to spend some time on her . i tested my 92 zr1 and it did the same thing 43lbs then snapped to 38 where it stayed for a good 20 min . the black car has rc injectors that are 2 yrs old . has anyone had their rc injectors leak . i regularly change my fuel filters in both cars (every 5 k miles ). any ideas

 

[Hib Halverson]

When you key up, see nominal pressure, the pressure fluctuates for a split second as the pump shuts off and then it goes down....that can be leaking injectors or it can be a leak inside the pump. There's a check valve in the pump which, if it leaks, will act like that, but....if it holds 38 lbs for several minutes, that not so bad.

It is unlikely that a fuel pressure issue is responsible for a plug that came out of the engine discolored.

Did you do a proper spark plug test "run" prior to looking at the plugs or did you simply pull them after normal street driving?

 

[jonszr1]

just pulled them after normal street driving. i felt a miss almost like when one of the original injectors went bad. the plug in number 8 is brown over the whole insulator .i put a fresh plug in and started up the car idled it for 5 min . shut it off, pulled the plug and it was medium brown just like the other one . i guess i need to pull the plenum and ck the coils(can only 1 cylinder go bad on the coils). ck the plug wire if not that pull the fuel rails out with the injectors attached and see if i have a leaker. guess if that cks out do a leak down test. but i dont know how to find tdc in these motors as there is no rotor , any ideas on doing this ?

 

[jonszr1]

hib , is my thought process on going about doing this the right way about finding the problem

 

[Hib Halverson]

I wouldn't worry about a plug that's a little brown. If it's wet and black or oily and black, the you need to be concered. Especially don't be concerned about plug color after idling.

Plug reading with today's gasoline is a dubious process at best.

You can find TDC using the conventional postitve stop method, but...you need a suitable piston stop. Not sure where you could get one for an LT5 but you probably could make one out of a Small-Block Chevy unit. But, I wouldn't worry about that unless you have evidence of a compression problem.

Is the engine missing?

 

[jonszr1]

i havent started it again in a few days . i will go start her and get back to you , thankyou for your help. it nice to have someone with your knowledge to help guide us

 

[southbay]

fuel injector cleaning

SouthBay Fuel Injectors open for business! Fuel Injector cleaning and remanufacturing service. Large inventory new and replacement fuel injectors. Come visit us at www.southbayfuelinjectors.com

 

[jonszr1]

thankyou so much for the info. nice to see a new vendor . but i use ficinjectors . he has been very good to me customer service is the best i have ever seen . awsome products at a very decent price

 

[southbay]

Not a problem, just wanted to introduce ourselves.

 

[jonszr1]

good deal and best of luck to you .thanx for supporting this site

 

[southbay]

Thanks, if there is ever anything that we can do for you in the future please do not hesitate to contact us!

 

[jonszr1]

well it looks like i have one bad injector .jon has replacements on the way

 

[Hib Halverson]

SouthBay Fuel Injectors open for business! Fuel Injector cleaning and remanufacturing service. Large inventory new and replacement fuel injectors. Come visit us at www.southbayfuelinjectors.com

I curious about your "remanufacturing" service. Does this apply to the various Bosch and Delco (Rochester) injectors used in Corvettes and how do you reman an injector?

 

[southbay]

yes it applies to bosch, rochester, seimen, delphi, etc. Inherintly, fuel injectors are not serviceable meaning they cannot be dismantled as you will destroy the injector. "Remanufactured" is a term that we use for cleaning and reconditioning utililzing the latest technology and bringing the injector back up to spec. in a "like new" condition where we can warrantee the injector. We cannot repair or replace broken pintles, coils, electrical connectors. We invite you to visit our website.

 

[Hib Halverson]

I understand "cleaning" as an ultrasonic process done on equipment such as the ASNU unit shown your web site. What I don't understand is the term "reconditioning". Can you elaborate a bit on the technology involved in doing that?

 

[southbay]

the injectors are not physically dismantled, we place them into 2 different types of ultrasonic cleaners, we flow test, leak test, check resistance replace all parts. When we clean our injectors we are emphatic about flowing them to within 1% or less, or right on the money! Manufacturers specs normally range between 3% and 6% on new injectors. Any sign of ohm difference or volt difference the injector is discarded. Less than 1% of injectors that come in have an electrical problem. Most injectors are dirty from carbon buildup on the pintle or from dirt in the fuel. What we advertise is what we stand by!

 

[Hib Halverson]

1%.
Typically, I've always looked for 1-1.5%.
You guys must have a large pool of injectors to work with.

 

[southbay]

Yes, within 1% or less! We do carry a large inventory of injectors, and we also carry new high performance injectors.