Fuel injectors/Pressure ? - ZR-1 Net Registry Forums

LGAFF · 09-07-2008

Last year I installed 2 new fuel pumps and new injectors, one set from SAP and the other Accels. I pressurized the fuel system and it jumps to 57lbs of pressure then drops to 41 and within 5 minutes pressure is down to 30 or less. I know Dominic had this issue earleir, wondering if the SAPs are crap and are leaking.

Times at the track are down fromlast year, MPH was down 2-3mph from last year. I was running 113-114.5 vs 115-117 last year.

LGAFF
92 ZR1
#234

LGAFF · 09-07-2008

Tested the Inj for resistence results as follows:

2ndry= 1)12.5 2)12.4 3)12.4 4)12.9 5)12.8 6)12.6 7)6.9

8)12.4

Primary= 1)15 2)15 3)15 4)15 5)14.8 6)15 7)15 8)15

Hmmmmmmmmm

LGAFF
92 ZR1
#234

09-07-2008

Sucks, so which injector brand failed?

LGAFF · 09-07-2008

SAPs.... only 1 year old.......bought these off the bay. As I was nice enough to test these for the forum members please send your check or money order to Lee Gaffigan

Guess I know what I am buying next week.

LGAFF
92 ZR1
#234

LGAFF · 09-07-2008

Byron sucked.......

Started running 12.8s at 113, even realed off a 12.64. Speed was slow but that might be the injector. I think they worked out the timing issue both sides consistently sucked for me and 1/8ths seem consistent in MPH and times.

I was going to try one more run then a motorcyle engine blew just past the 1/8th....guy launched parts over the friggin fences on both sides. That was worth $25 right there. I got 8 runs in, could have done 12-15 but spent time trying to figure out what was wrong.

I might as well change the coils also. I wonder if SAP makes those

LGAFF
92 ZR-1
#234

LGAFF · 09-07-2008

I was running 8.3-8.4@ 89MPH on both sides fairly consistently. I was not getting the second half pull I am used to out of the car. I had the same issue when I went in early May. This also means my 391hp Dyno run was with a crap injector.

LGAFF
92 ZR1
#234

Pete · 09-07-2008

Change the damn injector,LOL
Did you go to Byron?

What as your 1/8 MPH
Was your 60ft the same as last time.

Did you make any changes to the car,chip tune, plugs,etc.

Pete

Aurora40 · 09-08-2008

I don't know that Accel rates them at the same pressure as GM does. But I'd think get whatever # rating most people get, as they seem to work with no cal change.

FWIW, mine will hold pressure for 1/2 hour or more. Though yeah the manual doesn't suggest it has to in order to work properly.

You think the injectors are bad vs just one that was defective? I guess it's the same effort to change one as to change 8 though if you think they aren't a good product.

09-07-2008	#1
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Fuel injectors/Pressure ? Last year I installed 2 new fuel pumps and new injectors, one set from SAP and the other Accels. I pressurized the fuel system and it jumps to 57lbs of pressure then drops to 41 and within 5 minutes pressure is down to 30 or less. I know Dominic had this issue earleir, wondering if the SAPs are crap and are leaking. Times at the track are down fromlast year, MPH was down 2-3mph from last year. I was running 113-114.5 vs 115-117 last year. LGAFF 92 ZR1 #234

09-07-2008	#3
Jeffvette Guest Posts: n/a	Re: Fuel injectors/Pressure ? Sucks, so which injector brand failed?

09-07-2008	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Fuel injectors/Pressure ? SAPs.... only 1 year old.......bought these off the bay. As I was nice enough to test these for the forum members please send your check or money order to Lee Gaffigan Guess I know what I am buying next week. LGAFF 92 ZR1 #234

09-07-2008	#5
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Fuel injectors/Pressure ? Byron sucked....... Started running 12.8s at 113, even realed off a 12.64. Speed was slow but that might be the injector. I think they worked out the timing issue both sides consistently sucked for me and 1/8ths seem consistent in MPH and times. I was going to try one more run then a motorcyle engine blew just past the 1/8th....guy launched parts over the friggin fences on both sides. That was worth $25 right there. I got 8 runs in, could have done 12-15 but spent time trying to figure out what was wrong. I might as well change the coils also. I wonder if SAP makes those LGAFF 92 ZR-1 #234

09-07-2008	#6
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Fuel injectors/Pressure ? I was running 8.3-8.4@ 89MPH on both sides fairly consistently. I was not getting the second half pull I am used to out of the car. I had the same issue when I went in early May. This also means my 391hp Dyno run was with a crap injector. LGAFF 92 ZR1 #234

09-07-2008	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Fuel injectors/Pressure ? Tested the Inj for resistence results as follows: 2ndry= 1)12.5 2)12.4 3)12.4 4)12.9 5)12.8 6)12.6 7)6.9 8)12.4 Primary= 1)15 2)15 3)15 4)15 5)14.8 6)15 7)15 8)15 Hmmmmmmmmm LGAFF 92 ZR1 #234

09-07-2008	#7
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,667	Re: Fuel injectors/Pressure ? Change the damn injector,LOL Did you go to Byron? What as your 1/8 MPH Was your 60ft the same as last time. Did you make any changes to the car,chip tune, plugs,etc. Pete __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage

09-08-2008	#8
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,704	Re: Fuel injectors/Pressure ? I don't know that Accel rates them at the same pressure as GM does. But I'd think get whatever # rating most people get, as they seem to work with no cal change. FWIW, mine will hold pressure for 1/2 hour or more. Though yeah the manual doesn't suggest it has to in order to work properly. You think the injectors are bad vs just one that was defective? I guess it's the same effort to change one as to change 8 though if you think they aren't a good product.