Hard to start when cold?
Thread Starter
Melting Slicks
Joined: Jun 2000
Posts: 2,923
Likes: 1
From: Las Vegas NV
Need help on startup
1988 coupe, Z52
What should I look into to solve this problem? The engine runs fine and start right up when warm.
The engine was recently tear apart and put back with less than 400 miles on it. It does has an aftermarket head, trickflow. the trickflow head has higher flow.
- New AFPR set at 39 PSI, all injector are fairly new.
- Cold start injector was clean by Curz performance about 15k miles ago, and I can hear the cold start injector working when the ignition turned on in the morning.
- New fuel pump
- Everything were replace with new part when I rebuilt the engine, except the fuel filter and O2 sensor. I haven't check the TPS yet, but didn't think it has anything to do with hard start cold!
Could it be that the cold start need cleaning again? What else should I check?
Thanks,
What should I look into to solve this problem? The engine runs fine and start right up when warm.
The engine was recently tear apart and put back with less than 400 miles on it. It does has an aftermarket head, trickflow. the trickflow head has higher flow.
- New AFPR set at 39 PSI, all injector are fairly new.
- Cold start injector was clean by Curz performance about 15k miles ago, and I can hear the cold start injector working when the ignition turned on in the morning.
- New fuel pump
- Everything were replace with new part when I rebuilt the engine, except the fuel filter and O2 sensor. I haven't check the TPS yet, but didn't think it has anything to do with hard start cold!
Could it be that the cold start need cleaning again? What else should I check?
Thanks,
Last edited by VQT88Vette; Feb 16, 2005 at 12:35 PM.
Burning Brakes
Joined: Dec 2004
Posts: 825
Likes: 0
From: Hanging out back with the dark horses. Wa.
I had the same problem with my 88.
Not sure how I fixed it but it had something to do with the relay up by the wipermotor.
Also check your fuel Pressure when cold. When you first hit the key first thing in the morning check psi. The pump runs for 3 sec. then takes another 10 sec to reset with key off. do that a couple time and get the reading.
I think my problem was the relay had a bad wire that I found when I was fixing the wipers.
Sorry I can't be more help. Jeff
Not sure how I fixed it but it had something to do with the relay up by the wipermotor.
Also check your fuel Pressure when cold. When you first hit the key first thing in the morning check psi. The pump runs for 3 sec. then takes another 10 sec to reset with key off. do that a couple time and get the reading.
I think my problem was the relay had a bad wire that I found when I was fixing the wipers.
Sorry I can't be more help. Jeff
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
First check to see if the fuel rail is primed and holds prime when you turn the key On.
If fp is ok, check the CINJ/CLK fuse.
If ok, connect a DMM to the Tan wire at the cold start injector or at the Thermo Time Switch in the front of the intake base. When you cold start the voltage on the Tan wire should drop from +12Vdc to 0. As the engine warms up, that voltage will suddenly switch back to +12Vdc when the cold start injector is shut off.
Thread Starter
Melting Slicks
Joined: Jun 2000
Posts: 2,923
Likes: 1
From: Las Vegas NV
I think the relay you're talking about is the fuel pump relay and it locate on the firewall next to the wiper motor. That replay is fairly new also and I can hear the fuel squirting out of hte cold start when standing out side wit someone else turn the ignition on. I'll check the wiring as recommend.
Thread Starter
Melting Slicks
Joined: Jun 2000
Posts: 2,923
Likes: 1
From: Las Vegas NV
65Z01,
What's a CINJ/CLK fuse? :o
The fuel pressue hold when the ign. is on. I'll check again tonight to make sure.
Do I need to poke a hole into the tan wire for the Digital Meter?
What's a CINJ/CLK fuse? :o
The fuel pressue hold when the ign. is on. I'll check again tonight to make sure.
Do I need to poke a hole into the tan wire for the Digital Meter?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Oops, my bad...that should read CINJ/CLU; it is a 5 Amp fuse in the Aux Fuse Block located behind the center of the I/P in the multi-use center.
You can either pierce the Tan wire, or better, pull the connector and jumper the wires between the connector and the device.
You can either pierce the Tan wire, or better, pull the connector and jumper the wires between the connector and the device.
