I am trying to install some Precision 1000cc Injectors but they are bigger than the ones i currently have; 380cc. I have an AAM stage I fuel system. I got the injectors to sit properly without any leaks, however when I try to put on the plenum the fuel rails hit.

The injectors came with some spacers and I have the spacers from the 380cc injectors as well, but the rails still hit. Is the lower intake plenum supposed to be machined to fit these injectors? Or should I try to put the injectors on without any spacers, just the o-rings?

I bought the injectors used off a fellow my350z member, but they did not come with any instructions. Anyone got any experience installing these injectors?

--Jorge

 

Here are some pics of what im talking about






Thanks in advance for the help

 

Have you tried installing them without the spacers? If that doesn't work You can check out Motordyne, they make a lower plenum spacer for this very problem.

 

Youll have to get a spacer that goes between the lower collector and lower manifold. Most of the venders have them.

 

I know with RC injectors and our rails, we double up on the factory black spacers - they are just a hair smaller than the aluminum spacers RC provides, which is just enough clearance to keep the rails from hitting the lower plenum.

Not sure about those that you have there, though.

 

http://www.motordyneengineering.com/...dSpacer180.JPG
http://www.motordyneengineering.com/350Z.htm
get that they also have a 1/2 inch one.

 

We have the lower plenum spacer in stock. I know the Precision injectors are taller than the RC's, but not sure by how much.

Lower Plenum Spacer

 

Did you guys get my Cosworth in yet?

 

Haha, they told us 2 weeks, so we called them in 2 weeks, they told us 3 weeks, it has been 3 weeks...not holding my breath.

 

redzzand, any update on what you have decided to do to this fix this?

 

pull the spacers, see how far the injectors will go till they bottom out, measure for new spacers (washers work fine) try to reinstall manifold and see if it still hits. if it does, put tape on the mainfold inline with the fuel rails and grind away where the tape is mugged up from touching. there is a good amount of thickness to the manifold in the areas that need to be clearanced.
the motordyne spacer is a good idea also, but can make it so you can't run their plenum spacer which will yield better results than a manifold spacer and keep your a strut bar.

 

ok, i ordered a motordyne 1/4" spacer and i got it to clear the injectos. Now Im trying to scale the 1000cc injectors on the UTEC. I got the car to idle but the AFR is 10.6-10.7. I keep substracting on the 0 column and I can see the Mod MAFv. decreasing, but the inj. pulse width wont drop from 1.1-1.2. Im using the APS 750cc basemap as a start.

 

well good luck using the utec with 1000cc injectors, also are those low impedance?

 

The precision's are low impedance

 

you cant use low impedance injectors with the utec... i thought...

 

is this true? it could explain why I cant scale them. Guess its time to sell UTEC and buy a Haltech.

 

Yep either sell the utec and get the haltech.. or get the uprev Osirus and have them put a start up map with modified etc and cranking enrichment.. That way you can still use the utec but not have to spend over 2k on a ems, also in the process they will flash for your idle to be corrected and eliminate your speed limiter and push your redline higher if wanted.. Also, if the map isnt great you can always send back the osirus free of charge until they get it right.. Im doing this now and will receive it on monday.. ill let you know my experience on the first flash..

 

imma try using some resistors on the injectors to convert the power signal from high to low impedance. Theoretically, this should work just as well but keep me posted, I like to have all available options when making final decisions about things, and yeah 2k is a lot of cash for an EMS.

 

Ill let u know monday night or tues at the latest..... I already had a good Uprev experience with my initial basic flash.. So i figured wtf ill do the easier route of flashing my ecu any time i wanted to.. Rather than haltech which i would have to drive 7hrs or more to have tuned and cost me 3k+ (money could be used for future TT parts).. So right now they are sending me a flash with 750cc inj.. I just want my start ups to be like stock again..

 

i hear ya... i do all the tuning myself with some buddies; we all own a few shops. So buying the haltec is all i need to get my idle back. Im tying the resistors in a bit, if it dont work, i'll be buying a haltec in a months.