Performance question. - ZR-1 Net Registry Forums

BBBAD94ZR1 · 04-17-2006

I was wondering if this is a normal condition? Driving in 4th gear at around 3 to 4k rpms and and after shifting to 5th to cruise the rpms are around 1500 to 2k and when you give it a little throttle the car seems to lug and sputter a little at times. I was wondering if its the fact the car is in to high of a gear and the car is lugging? All other gears a fine it just seems as if the engine does not like low rpms at cruising speeds in 5th and 6th. Anyone experience this? If I drive the car at 2500 to 3k in 5th and 6th no issues.
Only mod is the halibeck chip and bnb exhaust.

Thanks
RAY

Tom · 04-17-2006

My 90 will pull smoothly from 50 mph in sixth gear and will also pull smoothly from 1500 rpm in fifth gear. It will not accelerat very quickly at 50 mph in sixth but it will pull smoothly.

Aurora40 · 04-17-2006

Quote:

Originally Posted by Tom

My 90 will pull smoothly from 50 mph in sixth gear and will also pull smoothly from 1500 rpm in fifth gear. It will not accelerat very quickly at 50 mph in sixth but it will pull smoothly.

Mine as well. Though prior to the new injectors it was rougher at low rpm operation. Afterwards, it's smooth smooth smooth, though obviously acceleration in 6th at 50mph is not exactly brisk. But it will pull fine, even up hills.

Kevin · 04-17-2006

sounds like bad injectors

BBBAD94ZR1 · 04-17-2006

No its not injectors, cars from 90-92 are all subject to bad injectors. 93 and up where revamped to eliminate the previous issues. My car only has 11 k miles and the flow rates are perfect on the injector sides. It is very uncommon for a 93 -95 to have bad injectors. Eventually all 90-92 lt5s will need to injectors.
Thanks
RAY

Kevin · 04-17-2006

Ray,
the late model injectors aren't SS as far as I know so they may still go bad. Pull the plenum and check the ohz on the. 11.5-13 is in range for good injectors. Lower and they are going bad.

tf95ZR1 · 04-17-2006

There was a prior post on this topic some time ago. Although
it makes sense to me that an engine may "bog", those more
knowledgable than me said this should not happen. One thing
they suggested was changing spark plugs which helped my
situation.
Good Luck,
Ted Feder
95 ZR1 #106 Blk/BLk
So. Cal.

Tom · 04-18-2006

You can check the injector resistance without pulling the plenum. Pull the connector at the ECM and check them from there. The electrical section from the Helms shop manual will show you which pins on the connector to check or go to Marc Haibeck's website and he has an article about checking the resistance through the ECM connector.

BBBAD94ZR1 · 04-18-2006

All injectors are up to specs, I took the car out today for a 2 hour cruise and it only happend one time going from 5th to 6th at around 2500rpm.
Other wise runs like a scalded cat. Maybe im just crazzzzzy.
RAY

04-17-2006	#2
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: Performance question. My 90 will pull smoothly from 50 mph in sixth gear and will also pull smoothly from 1500 rpm in fifth gear. It will not accelerat very quickly at 50 mph in sixth but it will pull smoothly.

04-17-2006	#4
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,629	Re: Performance question. sounds like bad injectors __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

04-17-2006	#5
BBBAD94ZR1 Join Date: Nov 2005 Location: NJ Posts: 298	Re: Performance question. No its not injectors, cars from 90-92 are all subject to bad injectors. 93 and up where revamped to eliminate the previous issues. My car only has 11 k miles and the flow rates are perfect on the injector sides. It is very uncommon for a 93 -95 to have bad injectors. Eventually all 90-92 lt5s will need to injectors. Thanks RAY __________________ [FONT=Century Gothic][SIZE=5][COLOR=black][I]:dancing[/I][/COLOR][/SIZE][/FONT]

04-17-2006	#6
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,629	Re: Performance question. Ray, the late model injectors aren't SS as far as I know so they may still go bad. Pull the plenum and check the ohz on the. 11.5-13 is in range for good injectors. Lower and they are going bad. __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

04-17-2006	#7
tf95ZR1 Join Date: Aug 2005 Location: Northridge, CA Posts: 1,461	Re: Performance question. There was a prior post on this topic some time ago. Although it makes sense to me that an engine may "bog", those more knowledgable than me said this should not happen. One thing they suggested was changing spark plugs which helped my situation. Good Luck, Ted Feder 95 ZR1 #106 Blk/BLk So. Cal.

04-17-2006	#1
BBBAD94ZR1 Join Date: Nov 2005 Location: NJ Posts: 298	Performance question. I was wondering if this is a normal condition? Driving in 4th gear at around 3 to 4k rpms and and after shifting to 5th to cruise the rpms are around 1500 to 2k and when you give it a little throttle the car seems to lug and sputter a little at times. I was wondering if its the fact the car is in to high of a gear and the car is lugging? All other gears a fine it just seems as if the engine does not like low rpms at cruising speeds in 5th and 6th. Anyone experience this? If I drive the car at 2500 to 3k in 5th and 6th no issues. Only mod is the halibeck chip and bnb exhaust. Thanks RAY __________________ [FONT=Century Gothic][SIZE=5][COLOR=black][I]:dancing[/I][/COLOR][/SIZE][/FONT]

04-18-2006	#8
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: Performance question. You can check the injector resistance without pulling the plenum. Pull the connector at the ECM and check them from there. The electrical section from the Helms shop manual will show you which pins on the connector to check or go to Marc Haibeck's website and he has an article about checking the resistance through the ECM connector.

04-18-2006	#9
BBBAD94ZR1 Join Date: Nov 2005 Location: NJ Posts: 298	Re: Performance question. All injectors are up to specs, I took the car out today for a 2 hour cruise and it only happend one time going from 5th to 6th at around 2500rpm. Other wise runs like a scalded cat. Maybe im just crazzzzzy. RAY __________________ [FONT=Century Gothic][SIZE=5][COLOR=black][I]:dancing[/I][/COLOR][/SIZE][/FONT]