Are these injectors original? - ZR-1 Net Registry Forums

chriskinzel · 01-27-2013

Last fall my 91 would stumble when I got on it. The car has a very sorted past with no records at all. I figured that all I needed was to change injectors assuming that they where the originals. I pulled the plenum and checked the ohms only to find that everyone of them was 14.0 to 14.1. One set is orangey yellow and the other set is black. Are these original, and they have not shorted yet, or has a p.o. changed them. If they are ok why would it stumble? I have changed spark plugs.

Marc Haibeck · 01-27-2013

Your primary injectors are Ford injectors. They have the Ford part number on them. Sometimes the part number has been obliterated by the supplier. They seem to work well. I have never seen one fail. The secondary injectors look like the OE injectors.

At what engine speed and throttle opening do you encounter the stumble?

chriskinzel · 01-27-2013

As I recall is was about 1500 to 2000 RPM. It only seems to happen when I really get on it. It seems to be starving for fuel. I have changed both pumps as well as the filter. I am getting 50 psi fuel pressure at idle, I have no idea where it is after I close the hood.

chriskinzel · 01-27-2013

I just decided to change all 16 injectors. Those ones from Ford (yes they said Ford on them) looked a little funky. This way I know at least the injectors are OK. I will order new spark plug wires and replace them before I put the plenum back on. Mine still say LT5 on them, so they are at least 22 years old. Thanks for the help Marc. I just finished watching you on video be fore tackling this project. You gave me courage!!

XfireZ51 · 01-27-2013

Marc,

Are the FORD injectors the same as the Accels? IOW, are they the SAME injectors?

Marc Haibeck · 01-28-2013

Chris,

50 psi fuel pressure at idle is too high. 43 psi +/- 1 psi is normal at sea level. Don't worry about it with respect to the stumble problem though. High fuel pressure at 50 psi won't cause a stumble, misfire or roughness.

Maybe you have a shorted secondary injector causing the stumble? Check their electrical resistance. As they approach 6 ohms they stop flowing.

Dominic,

The Ford injectors have a different physical shape than the Accel injectors. I don't know who manufactures either one.

01-27-2013	#2
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 254	Re: Are these injectors original? Your primary injectors are Ford injectors. They have the Ford part number on them. Sometimes the part number has been obliterated by the supplier. They seem to work well. I have never seen one fail. The secondary injectors look like the OE injectors. At what engine speed and throttle opening do you encounter the stumble?

01-27-2013	#3
chriskinzel Join Date: Nov 2011 Location: Salt Lake City, Utah Posts: 167	Re: Are these injectors original? As I recall is was about 1500 to 2000 RPM. It only seems to happen when I really get on it. It seems to be starving for fuel. I have changed both pumps as well as the filter. I am getting 50 psi fuel pressure at idle, I have no idea where it is after I close the hood.

01-27-2013	#4
chriskinzel Join Date: Nov 2011 Location: Salt Lake City, Utah Posts: 167	Re: Are these injectors original? I just decided to change all 16 injectors. Those ones from Ford (yes they said Ford on them) looked a little funky. This way I know at least the injectors are OK. I will order new spark plug wires and replace them before I put the plenum back on. Mine still say LT5 on them, so they are at least 22 years old. Thanks for the help Marc. I just finished watching you on video be fore tackling this project. You gave me courage!!

01-27-2013	#5
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,686	Re: Are these injectors original? Marc, Are the FORD injectors the same as the Accels? IOW, are they the SAME injectors?

01-28-2013	#6
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 254	Re: Are these injectors original? Chris, 50 psi fuel pressure at idle is too high. 43 psi +/- 1 psi is normal at sea level. Don't worry about it with respect to the stumble problem though. High fuel pressure at 50 psi won't cause a stumble, misfire or roughness. Maybe you have a shorted secondary injector causing the stumble? Check their electrical resistance. As they approach 6 ohms they stop flowing. Dominic, The Ford injectors have a different physical shape than the Accel injectors. I don't know who manufactures either one.