Bad injectors or vacuum leak? - ZR-1 Net Registry Forums

gen2rt · 08-20-2014

I have a 1994, 19,000 miles, haibeck intake & port polish, headers.
Car suddenly has no bottom end, meaning bad stumble/dies at idle, when I get into it everything is fine. Since the car sits a lot my initial thought was bad primary injector(s). After searching forum, vacuum leak also looks to be a possibility. Looking for input from anyone experiencing something similar.

Thanks,
Jack

Kevin · 08-20-2014

with the miles I'm going to say injectors. a vac leak will cause the car to fall flat high in the rpm band

LGAFF · 08-20-2014

make sure your MAP sensors are connected

Ccmano · 08-20-2014

Quote:

Originally Posted by LGAFF

make sure your MAP sensors are connected

I'm with Lee... fuel pump possible too. My money is on the MAP sensor tho.
H

LGAFF · 08-20-2014

I was having an issue at cruise......had rotted rubber on the MAP sensor that was not visible until close inspection....Fuel Pressure Regulator too

Demps · 08-20-2014

Jack,
Where are you located?
Ted

tccrab · 08-20-2014

Map sensor hose is first guess.
Does it smoke on startup?
Second guess is fueling, either fuel pumps or filter.

Since it's a '94, injectors aren't as likely to be at fault as if it were a '90 or '91.

'Crabs

gen2rt · 08-22-2014

Thanks for the responses. I'll try the MAP sensor hose/connections. The ZR is parked in Colorado, I mostly live in Reno though. I'll hold off ordering new injectors and will dig into the MAP sensors when I get back to CO (in a couple months). I hope that's what it is, would rather not get into a plenum pull if I don't need to.
If the MAP sensor is ruled out, I'll start looking at the other suggestions.
I'll post back here what I find for reference.

Jack

XfireZ51 · 08-22-2014

Quote:

Originally Posted by gen2rt

Thanks for the responses. I'll try the MAP sensor hose/connections. The ZR is parked in Colorado, I mostly live in Reno though. I'll hold off ordering new injectors and will dig into the MAP sensors when I get back to CO (in a couple months). I hope that's what it is, would rather not get into a plenum pull if I don't need to.
If the MAP sensor is ruled out, I'll start looking at the other suggestions.
I'll post back here what I find for reference.

Jack

Jack,

I'll be in Denver next weekend. Where is it in CO. Darby and I can check it out.

gen2rt · 08-23-2014

Xfire,

PM sent.

thanks,
Jack

08-20-2014	#1
gen2rt Join Date: Oct 2010 Location: NV Posts: 38	Bad injectors or vacuum leak? I have a 1994, 19,000 miles, haibeck intake & port polish, headers. Car suddenly has no bottom end, meaning bad stumble/dies at idle, when I get into it everything is fine. Since the car sits a lot my initial thought was bad primary injector(s). After searching forum, vacuum leak also looks to be a possibility. Looking for input from anyone experiencing something similar. Thanks, Jack

08-20-2014	#2
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,624	Re: Bad injectors or vacuum leak? with the miles I'm going to say injectors. a vac leak will cause the car to fall flat high in the rpm band __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

08-20-2014	#3
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Bad injectors or vacuum leak? make sure your MAP sensors are connected __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

08-20-2014	#5
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Bad injectors or vacuum leak? I was having an issue at cruise......had rotted rubber on the MAP sensor that was not visible until close inspection....Fuel Pressure Regulator too __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

08-20-2014	#6
Demps Join Date: Jan 2006 Location: Niceville Posts: 1,000	Re: Bad injectors or vacuum leak? Jack, Where are you located? Ted

08-20-2014	#7
tccrab Join Date: Oct 2004 Location: Folsom CA Posts: 1,657	Re: Bad injectors or vacuum leak? Map sensor hose is first guess. Does it smoke on startup? Second guess is fueling, either fuel pumps or filter. Since it's a '94, injectors aren't as likely to be at fault as if it were a '90 or '91. 'Crabs Last edited by tccrab; 08-20-2014 at 07:03 PM.

08-22-2014	#8
gen2rt Join Date: Oct 2010 Location: NV Posts: 38	Re: Bad injectors or vacuum leak? Thanks for the responses. I'll try the MAP sensor hose/connections. The ZR is parked in Colorado, I mostly live in Reno though. I'll hold off ordering new injectors and will dig into the MAP sensors when I get back to CO (in a couple months). I hope that's what it is, would rather not get into a plenum pull if I don't need to. If the MAP sensor is ruled out, I'll start looking at the other suggestions. I'll post back here what I find for reference. Jack

08-23-2014	#10
gen2rt Join Date: Oct 2010 Location: NV Posts: 38	Re: Bad injectors or vacuum leak? Xfire, PM sent. thanks, Jack