LT1 has spark but no fuel pressure - LS1TECH

Log In 


LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT1 has spark but no fuel pressure

Reply
 
Thread Tools Search this Thread
Old 08-05-2011, 03:03 PM   #1
Teching In
Thread Starter
 
1996CamaroZ28's Avatar
 
Join Date: Jan 2009
Posts: 35
Default LT1 has spark but no fuel pressure

Okay this may sound like an obvious fuel pump problem but the fuel pump is brand new. Vehicle is 96 camaro z28. Has a fuel pressure tester on schrader valve and it reads 0psi while cranking and while the pump primes. Its a brand new TRE 255 pump with brand new fuel filter. Tested opti at school and its fine, brand new ICM, brand new spark plugs and brand new wires. Pulled the wire out of the ICM and it sparks while cranking. Hooked it back up and pulled the other side out of the opti, it sparks while cranking. After cranking a few times all I smell is unburnt fuel from the engine bay. All fuses are good. After sitting for a few mins the car will act like its going to start but then just goes to back to just cranking. Any ideas?
1996CamaroZ28 is offline   Reply With Quote
Old 08-05-2011, 05:00 PM   #2
TECH Junkie
 
shbox's Avatar
 
Join Date: Dec 2008
Location: Little Rock, AR
Posts: 3,739
Default

Are you sure the gauge you are using actually works? Have you tried it on another vehicle?
shbox is offline   Reply With Quote
Old 08-05-2011, 05:44 PM   #3
Teching In
Thread Starter
 
1996CamaroZ28's Avatar
 
Join Date: Jan 2009
Posts: 35
Default

No, I can't really use it on another vehicle because the other two that I have don't have schrader valves. I suppose I could try it on a friends, but the gauge was brand new out of the box and I have measured 34psi with that gauge on this car Before I replaced the factory pump for this TRE. The car ran fine until connections came loose in the tank and I had to reconnect those. This pump has been a nightmare since day one.. But its brand new..
1996CamaroZ28 is offline   Reply With Quote
Old 08-05-2011, 09:11 PM   #4
Teching In
Thread Starter
 
1996CamaroZ28's Avatar
 
Join Date: Jan 2009
Posts: 35
Default

Any other help will be greatly appreciated
1996CamaroZ28 is offline   Reply With Quote
Old 08-05-2011, 09:33 PM   #5
TECH Regular
iTrader: (2)
 
rich5368's Avatar
 
Join Date: Apr 2010
Location: Cheyenne, WY
Posts: 442
Default

If you smell unburnt fuel and its not puddled up somewhere something has to be up with your gauge. sounds like you have fuel. did you change the filter?
rich5368 is offline   Reply With Quote
Old 08-05-2011, 10:43 PM   #6
Teching In
Thread Starter
 
1996CamaroZ28's Avatar
 
Join Date: Jan 2009
Posts: 35
Default

Quote:
Originally Posted by rich5368 View Post
If you smell unburnt fuel and its not puddled up somewhere something has to be up with your gauge. sounds like you have fuel. did you change the filter?
Brand new. Even took it off and checked to make sure. Its good
1996CamaroZ28 is offline   Reply With Quote
Old 08-06-2011, 12:30 AM   #7
That's MISTER MODERATOR
iTrader: (9)
 
Paul Bell's Avatar
 
Join Date: Nov 2005
Location: NYC
Posts: 7,156
Default

Pop off the larger fuel line at the fuel rail, the feed one. Hold it in a bucket and have a buddy put the key to "on" but don't start crank the engine.

When the pump primes, you should have a good gush of fuel into the bucket.

BE CAREFUL of splashed fuel. NO SMOKING!
Paul Bell is offline   Reply With Quote
Old 08-06-2011, 01:27 AM   #8
Teching In
Thread Starter
 
1996CamaroZ28's Avatar
 
Join Date: Jan 2009
Posts: 35
Default

Thanks Paul, I will try that first thing tomorrow.
1996CamaroZ28 is offline   Reply With Quote
Old 08-06-2011, 11:02 AM   #9
TECH Resident
iTrader: (1)
 
Big Al's Avatar
 
Join Date: May 2005
Posts: 972
Default

Not to swipe the thread, but: My Chilton's shows a "prime" lead in the fuel pump circuit. Any one know where it is? Would be helpful for the OP.

Al 95 Z28 with two Walbro 255's in the tank
Big Al is offline   Reply With Quote
Old 08-06-2011, 11:07 AM   #10
Village Troll
iTrader: (2)
 
SS RRR's Avatar
 
Join Date: Oct 2002
Location: Jackstandican
Posts: 8,061
Default

For some reason I've had to muck around with a fuel pressure gauge to get it to read pressure on the Schraeder valve whether the gauge is used or new. Try unfastening and refastening it several times.
Quote:
Originally Posted by Paul Bell View Post
Pop off the larger fuel line at the fuel rail, the feed one. Hold it in a bucket and have a buddy put the key to "on" but don't start crank the engine.

When the pump primes, you should have a good gush of fuel into the bucket.

BE CAREFUL of splashed fuel. NO SMOKING!
The only thing that will tell you is if the pump works just enough to move fuel. Doesn't tell you at what pressure which can mean a lot.

Quote:
Originally Posted by Big Al View Post
Not to swipe the thread, but: My Chilton's shows a "prime" lead in the fuel pump circuit. Any one know where it is? Would be helpful for the OP.

Al 95 Z28 with two Walbro 255's in the tank
SS RRR is online now   Reply With Quote
Old 08-08-2011, 06:52 PM   #11
Teching In
Thread Starter
 
1996CamaroZ28's Avatar
 
Join Date: Jan 2009
Posts: 35
Default

Above post really didn't serve me any help but....

--------------------------------------------------------------------------------

Okay I pulled the fuel pump assembly out and found that there was a pin hole sized hole in one of the two fuel lines. I replaced both fuel lines to be safe and put everything back together(all wiring was hooked up and looked up to par). Primed the system and still reading 0 psi. Went back and pulled the fuel lines above the tank apart and fuel sprayed everywhere, so the lines are priming, but why is there no fuel pressure?

I then unhooked the number one spark plug wire and put o screw driver very close to the end socket of the wire, no spark jumped. Replugged it in and unplugged the wire going from the opti to the coil, from the coil side and did the same thing, no spark. Plugged it back into the coil and unplugged the other end going to the opti, had spark. So i have narrowed it down to Opti, ICM, or Fuel pressure regulator. I also removed the vaccuum line on the back of the regulator and no fuel came out. Couldnt get back there to smell, but im guessing its fine. Any thoughts or Ideas before I just start replacing stuff till the problem is fixed?
1996CamaroZ28 is offline   Reply With Quote
Old 08-08-2011, 07:00 PM   #12
TECH Fanatic
iTrader: (11)
 
defaultexistence's Avatar
 
Join Date: Sep 2005
Location: fort walton beach,fl
Posts: 1,954
Default

Can u hear the pump cycle by turning on key? Did you install the filter with it flowing the correct way? Have you pulled a supply line off at the rails and cycled key to see if it's making it to the rails?

Last edited by defaultexistence; 08-08-2011 at 07:11 PM.
defaultexistence is offline   Reply With Quote
Old 08-08-2011, 07:08 PM   #13
That's MISTER MODERATOR
iTrader: (9)
 
Paul Bell's Avatar
 
Join Date: Nov 2005
Location: NYC
Posts: 7,156
Default

Quote:
Originally Posted by defaultexistence View Post
....seemif it's machining it to the rails?
I sound like that after I've had a few. Which I'm working on right now....
Paul Bell is offline   Reply With Quote
Old 08-08-2011, 07:11 PM   #14
TECH Fanatic
iTrader: (11)
 
defaultexistence's Avatar
 
Join Date: Sep 2005
Location: fort walton beach,fl
Posts: 1,954
Default

Quote:
Originally Posted by Paul Bell View Post
I sound like that after I've had a few. Which I'm working on right now....
LOL! Yea auto correct
On the iPhone is a joke....
defaultexistence is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Weak spark, no start 1993 Corvette hrcslam LT1-LT4 Modifications 20 07-06-2016 07:03 PM
LT1 crank but no start, have done tests, PCM or Opti? Ignition Switch? No spark. Z28Roxy LT1-LT4 Modifications 1 08-11-2012 02:24 PM
Spark at coil, no spark at plugs, wtf!!!??? xrambbc LT1-LT4 Modifications 27 10-12-2011 11:59 PM
wont start has spark and fuel RED PUNISHER Z LT1-LT4 Modifications 17 01-11-2011 12:26 PM
Still no start.... Red96TA LT1-LT4 Modifications 25 12-09-2007 02:21 PM


Tags
86, 95, 96, camaro, diagram, fuel, lt1, noise, pop, pressure, prime, primes, pump, rail, regulator, spark, wiring

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off



All times are GMT -5. The time now is 12:44 AM.