91 ZR-1 Cutting Out Under Load - Page 6 - ZR-1 Net Registry Forums

Tom · 10-18-2006

The steps you listed will check the primary injector coils only. Take a look at the schematic and you will see why these steps only check the primaries and you will have to make additional measurements to check the secondary injector coils. There is a good chance secondary coils are going bad if the primary coils are failing and you might as well check and take care of everything at the same time.

GregCrowe · 10-18-2006

Thanks Tom, are the secondary injectors the same units as the primaries? IE......... do I just buy two sets of the Accels?

Tom · 10-18-2006

I don't know for sure for your '91, but there are other threads about injectors if you do a search, several of the people who have replied to this thread have replaced their injectors. My '90 with a little over 36,000 miles still has the original injectors, but as far as I can tell I have never used gasoline that had alcohol in it. That will probably change now since California is removing the MTBE and I believe is going to alcohol in the gasoline.

GregCrowe · 10-18-2006

Well, I do know for a fact that I've never used gasoline with alcohol in it. I'll try to do the injector resistance test this weekend.

1990 quasar blue · 10-18-2006

Quote:

Originally Posted by GregCrowe

Well, I do know for a fact that I've never used gasoline with alcohol in it. I'll try to do the injector resistance test this weekend.

http://cgi.ebay.com/ebaymotors/Accel...QQcmdZViewItem
You need two sets plus the thicker rubber Orings from Marc Haibeck. I think there twenty bucks. I don't know about the later style injectors. How about ethanol? All the gas here has 10%.

GregCrowe · 10-18-2006

OK cool, now all I need to know is if these Accels can be used on both the primary and secondary side. I do know according to GM parts, the primary and secondary injector part numbers are different.

jonszr1 · 10-18-2006

I believe you order 16 same part no of the accels just get the o-ring setup from mark

1990 quasar blue · 10-18-2006

Quote:

Originally Posted by GregCrowe

OK cool, now all I need to know is if these Accels can be used on both the primary and secondary side.

Yes.

Lots of info.

http://forums.corvetteforum.com/sear...archid=3367392

http://forums.corvetteforum.com/show...ight=injectors

george henry · 10-20-2006

My 2 cents: My '90 had a similar problem, cutting out (missing) under load when the engine was hot (all was fine with cold engine). Did all the usual and simple stuff first. The guy's at the corvette shop suspected a coil breaking down when hot. My fuel pressure was 42psi on either pump or both pumps together. Should be 52-55 psi. Is yours still 32psi? not good. Under load the engine would be starving for fuel. Anyway, since the plenum was coming off, I replaced the fuel pressure regulator (pressure is now 52psi) and all four coils. Problem gone, I can now do 180mph again. Regulator was $125 at GMPartsdirect.com.

Good luck

GregCrowe · 08-27-2008

Well, finally after 2 years I have now ordered the Accel fuel injectors and a new fuel pressure regulator. This morning I have a new problem. I am now informed that the 90-92 Corvette ZR1 fuel pressure regulator is a discontinued item. I'm still reading 32 psi with a new fuel filter. Any suggestions on where to get a FPR ? An adjustable one would be ideal.

10-18-2006	#51
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: 91 ZR-1 Cutting Out Under Load The steps you listed will check the primary injector coils only. Take a look at the schematic and you will see why these steps only check the primaries and you will have to make additional measurements to check the secondary injector coils. There is a good chance secondary coils are going bad if the primary coils are failing and you might as well check and take care of everything at the same time.

10-18-2006	#52
GregCrowe Join Date: Sep 2004 Location: Oklahoma Posts: 111	Re: 91 ZR-1 Cutting Out Under Load Thanks Tom, are the secondary injectors the same units as the primaries? IE......... do I just buy two sets of the Accels?

10-18-2006	#53
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: 91 ZR-1 Cutting Out Under Load I don't know for sure for your '91, but there are other threads about injectors if you do a search, several of the people who have replied to this thread have replaced their injectors. My '90 with a little over 36,000 miles still has the original injectors, but as far as I can tell I have never used gasoline that had alcohol in it. That will probably change now since California is removing the MTBE and I believe is going to alcohol in the gasoline.

10-18-2006	#54
GregCrowe Join Date: Sep 2004 Location: Oklahoma Posts: 111	Re: 91 ZR-1 Cutting Out Under Load Well, I do know for a fact that I've never used gasoline with alcohol in it. I'll try to do the injector resistance test this weekend.

10-18-2006	#56
GregCrowe Join Date: Sep 2004 Location: Oklahoma Posts: 111	Re: 91 ZR-1 Cutting Out Under Load OK cool, now all I need to know is if these Accels can be used on both the primary and secondary side. I do know according to GM parts, the primary and secondary injector part numbers are different.

10-18-2006	#57
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,407	Re: 91 ZR-1 Cutting Out Under Load I believe you order 16 same part no of the accels just get the o-ring setup from mark

10-20-2006	#59
george henry Join Date: Aug 2006 Location: San Diego, CA Posts: 24	Re: 91 ZR-1 Cutting Out Under Load My 2 cents: My '90 had a similar problem, cutting out (missing) under load when the engine was hot (all was fine with cold engine). Did all the usual and simple stuff first. The guy's at the corvette shop suspected a coil breaking down when hot. My fuel pressure was 42psi on either pump or both pumps together. Should be 52-55 psi. Is yours still 32psi? not good. Under load the engine would be starving for fuel. Anyway, since the plenum was coming off, I replaced the fuel pressure regulator (pressure is now 52psi) and all four coils. Problem gone, I can now do 180mph again. Regulator was $125 at GMPartsdirect.com. Good luck

08-27-2008	#60
GregCrowe Join Date: Sep 2004 Location: Oklahoma Posts: 111	Re: 91 ZR-1 Cutting Out Under Load Well, finally after 2 years I have now ordered the Accel fuel injectors and a new fuel pressure regulator. This morning I have a new problem. I am now informed that the 90-92 Corvette ZR1 fuel pressure regulator is a discontinued item. I'm still reading 32 psi with a new fuel filter. Any suggestions on where to get a FPR ? An adjustable one would be ideal.