Injector issue with 1990? - Page 2 - ZR-1 Net Registry Forums

jss06c6 · 07-11-2017

Man, it's been a long time since we've seen 98 or 100 octane fuel! Brings back fond memories of big block solid lifter engines at 13:1 compression and a BIG cam!!
I
Have you checked your fuel pressure? It does sound like a fuel issue...

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cp1joel · 07-11-2017

That is interesting ! I would have assumed the US would be getting higher octane fuel as well. Quite a few years ago 100 octane was available in some locations, but now 98, 95 and 91 are readily available.

I have not checked the fuel pressure, good point indeed.

I did notice when the issue was happening, the oil pressure gauge was dropping to about half way when coming to idle, then moving close to or above the 3/4 mark on the gauge.

I don't recall seeing it fluctuate like this before ( I may be wrong).

I am taking the ZR1 to a mechanic on Friday, getting him to give it a good look over and try and sort some of these issues out. He is well recommend for woking on chevy and high performance engines. Very difficult to find anyone who will touch the LT5 in Aus given the low numbers here.

Will keep you all posted on how it all goes.

BigJohn · 07-11-2017

We have 93 here!
E-85 is 105.

gtcollins@maxnet.co.nz · 07-11-2017

Hi All our fuel here in the South Pacific is rated with the ron (Research Octane Number ) where yours is mon
(Motor Octane Number)
So our 98 is about your 91 or 93 when I got my ZR-1 po said he ran it on our 91 I tyred it and the engine detonated so I only run BP 98
Regards Glen Collins

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WARP TEN · 07-12-2017

Now I realize I am dating myself, but in the early 70s I used to fill up my '68 Hemi Road Runner with Sunoco 260, which was 104 octane. It needed it to run well. Wish they still sold that. --Bob

BigJohn · 07-12-2017

Local Sunoco has Cam2 racing fuel.

Rodder · 07-12-2017

In Europe the octane is rated in RON aswell and US use RON+MON/2 which gives a lower value. In Sweden we have 95,98 and E85. An old car magazine test showed our 98 to equal a US rating 92,5 to 93,25 depending on brand. Today some 98 octan is ethanol free depending on refinery the rest is "said" to be up to 5%.

Thomas

gtcollins@maxnet.co.nz · 07-12-2017

Our BP 98 is ethanol is free Mobil isn't
Glen

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George Maz · 07-12-2017

"Quad-pack"
This module controls injector function on 1990 Z.

5ABI VT · 07-13-2017

Me personally I have been mulling over the fuel pressure regulator of late. Few have changed it, some have posted pics and they didnt look too good inside. I wonder as all of our cars are similar in age if it would be a good idea to replace it. Any records of fuel pumps being replaced?

07-11-2017	#11
jss06c6 Join Date: Aug 2015 Location: Magnolia, Texas Posts: 884	Re: Injector issue with 1990? Man, it's been a long time since we've seen 98 or 100 octane fuel! Brings back fond memories of big block solid lifter engines at 13:1 compression and a BIG cam!! I Have you checked your fuel pressure? It does sound like a fuel issue... Sent from my XT1585 using ZR-1 Net Registry mobile app

07-11-2017	#12
cp1joel Join Date: Jan 2017 Location: Brisbane Posts: 31	Re: Injector issue with 1990? That is interesting ! I would have assumed the US would be getting higher octane fuel as well. Quite a few years ago 100 octane was available in some locations, but now 98, 95 and 91 are readily available. I have not checked the fuel pressure, good point indeed. I did notice when the issue was happening, the oil pressure gauge was dropping to about half way when coming to idle, then moving close to or above the 3/4 mark on the gauge. I don't recall seeing it fluctuate like this before ( I may be wrong). I am taking the ZR1 to a mechanic on Friday, getting him to give it a good look over and try and sort some of these issues out. He is well recommend for woking on chevy and high performance engines. Very difficult to find anyone who will touch the LT5 in Aus given the low numbers here. Will keep you all posted on how it all goes.

07-11-2017	#13
BigJohn Join Date: Feb 2012 Location: Ledyard,CT Posts: 8,223	Re: Injector issue with 1990? We have 93 here! E-85 is 105.

07-11-2017	#14
gtcollins@maxnet.co.nz Join Date: Mar 2015 Location: New Zealand Posts: 385	Re: Injector issue with 1990? Hi All our fuel here in the South Pacific is rated with the ron (Research Octane Number ) where yours is mon (Motor Octane Number) So our 98 is about your 91 or 93 when I got my ZR-1 po said he ran it on our 91 I tyred it and the engine detonated so I only run BP 98 Regards Glen Collins Sent from my SM-G930F using ZR-1 Net Registry mobile app

07-12-2017	#15
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,084	Re: Injector issue with 1990? Now I realize I am dating myself, but in the early 70s I used to fill up my '68 Hemi Road Runner with Sunoco 260, which was 104 octane. It needed it to run well. Wish they still sold that. --Bob __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough"

07-12-2017	#16
BigJohn Join Date: Feb 2012 Location: Ledyard,CT Posts: 8,223	Re: Injector issue with 1990? Local Sunoco has Cam2 racing fuel.

07-12-2017	#17
Rodder Join Date: Mar 2007 Location: Sweden Posts: 28	Re: Injector issue with 1990? In Europe the octane is rated in RON aswell and US use RON+MON/2 which gives a lower value. In Sweden we have 95,98 and E85. An old car magazine test showed our 98 to equal a US rating 92,5 to 93,25 depending on brand. Today some 98 octan is ethanol free depending on refinery the rest is "said" to be up to 5%. Thomas

07-12-2017	#18
gtcollins@maxnet.co.nz Join Date: Mar 2015 Location: New Zealand Posts: 385	Re: Injector issue with 1990? Our BP 98 is ethanol is free Mobil isn't Glen Sent from my SM-G930F using ZR-1 Net Registry mobile app

07-13-2017	#20
5ABI VT Join Date: Jun 2013 Location: Toronto Posts: 783	Re: Injector issue with 1990? Me personally I have been mulling over the fuel pressure regulator of late. Few have changed it, some have posted pics and they didnt look too good inside. I wonder as all of our cars are similar in age if it would be a good idea to replace it. Any records of fuel pumps being replaced?