Fuel Pressure Low only on first cold Start.
11-01-2015, 07:40 PM
#1
Member
Thread Starter
iTrader: (1)
Join Date: Nov 2013
Location: Cincinnati, OH
Posts: 112
Likes: 0
Received 5 Likes
on
3 Posts
Car: 2002 Camaro SS
Engine: Built LS
Transmission: T56
Axle/Gears: 3.73
Fuel Pressure Low only on first cold Start.
This is on a 91 5.0 TPI. The first start after sitting takes about 4-5 seconds to start. I have a fuel pressure gauge connected and the car will prim too around 30 PSI. As soon as I start cranking the PSI drops to about 20.
As soon as the car starts it jumps up to almost 40 PSI. If I take the vacuum line off the regulator it idles at 43 where it should be.
The pressure takes many hours to bleed off. If I start the car again after the first it starts right up because its still over 40psi at the rails.
The car has brand new bosch 3 injectors from South Bay and new Wix Fuel Filter. Everything else is stock fuel wise.
Any ideas of what cause this?
As soon as the car starts it jumps up to almost 40 PSI. If I take the vacuum line off the regulator it idles at 43 where it should be.
The pressure takes many hours to bleed off. If I start the car again after the first it starts right up because its still over 40psi at the rails.
The car has brand new bosch 3 injectors from South Bay and new Wix Fuel Filter. Everything else is stock fuel wise.
Any ideas of what cause this?
11-05-2015, 02:53 PM
#2
Senior Member
Join Date: May 2006
Location: NY
Posts: 581
Likes: 0
Received 0 Likes
on
0 Posts
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: Fuel Pressure Low only on first cold Start.
Weak FP or brush's starting to GO. System holds & maintains Pressure... Initial prime is low.
11-05-2015, 04:41 PM
#3
Member
Thread Starter
iTrader: (1)
Join Date: Nov 2013
Location: Cincinnati, OH
Posts: 112
Likes: 0
Received 5 Likes
on
3 Posts
Car: 2002 Camaro SS
Engine: Built LS
Transmission: T56
Axle/Gears: 3.73
Re: Fuel Pressure Low only on first cold Start.
Are you saying the fuel pump is starting to go or the brushes on the starter?
11-06-2015, 12:06 PM
#4
Senior Member
Join Date: May 2006
Location: NY
Posts: 581
Likes: 0
Received 0 Likes
on
0 Posts
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: Fuel Pressure Low only on first cold Start.
Are you serious. I'm sorry. What does your starter have to do with a FP. There is a brushed motor in all FP's
11-06-2015, 02:47 PM
#6
Member
Thread Starter
iTrader: (1)
Join Date: Nov 2013
Location: Cincinnati, OH
Posts: 112
Likes: 0
Received 5 Likes
on
3 Posts
Car: 2002 Camaro SS
Engine: Built LS
Transmission: T56
Axle/Gears: 3.73
Re: Fuel Pressure Low only on first cold Start.
Must be having a bad day? It's Friday man cheer up.
11-06-2015, 03:37 PM
#7
Senior Member
Join Date: May 2006
Location: NY
Posts: 581
Likes: 0
Received 0 Likes
on
0 Posts
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: Fuel Pressure Low only on first cold Start.
I'm as cheerful. As can be. You have never seen. Worn carbon brush. Contacts. Sorry, I tried to help you Diagnose
Last edited by 88gta3508; 11-06-2015 at 03:41 PM.
Trending Topics
11-06-2015, 03:46 PM
#8
Senior Member
Join Date: May 2006
Location: NY
Posts: 581
Likes: 0
Received 0 Likes
on
0 Posts
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: Fuel Pressure Low only on first cold Start.
Above is a motor from a GM "delco" - FP. When the brush contacts are WORN = intermittent voltage, Thus weak Pump. Happy Friday!!!!! or the wet Magnets can- de-bond from the CAN = Locked up FP..
Last edited by 88gta3508; 11-06-2015 at 03:50 PM.
11-06-2015, 04:14 PM
#10
Senior Member
Join Date: May 2006
Location: NY
Posts: 581
Likes: 0
Received 0 Likes
on
0 Posts
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: Fuel Pressure Low only on first cold Start.
Class.. Dis-missed. See Ya next time...
Thread
Thread Starter
Forum
Replies
Last Post
gunznrosez87
Tech / General Engine
10
10-14-2015 11:56 PM