Fuel Pressure reads 40 Psi

Scaramanga · 01-19-2006, 05:39 PM

Is this too much? I'm having some randon no starts from my 92 Lumina 3.1L .. When it won't start I can check for fire and it's sparking fine. Last time it didn't start I put a fuel pressure gauge on it and it read 40 psi, then 42 psi when I turned the motor over. Is the fuel pressure regulator flooding out the engine? Usually I can wait 10-15 mins and it starts like up fine, and runs good.. Any suggestions?

maxwedge · 01-19-2006, 05:59 PM

Fuel pressure is ok, for a not running reading.

Scaramanga · 01-19-2006, 06:54 PM

Ok. It wouldn't start a few minutes ago. I connected the guage and hit the key and it went up to 40/41 psi. I turned it over and it went to 42 psi.. I left it connected and watch it SLOWLY drop psi with just the key on - Is this normal? I'm at loss here on why sometimes it won't start... Most of the time when it does start it fires up good, but It has a FEW times ldled rough on startup (usually after I keep trying to start it when it won't) and has a few times backfired during this. After it idles for a while (me giving it a little gas) it runs fine.. Any suggestions?

Fuel Pump/Fuel filter has 30k miles or so on it (been 3 years though)
I've replaced
Crank position senor, ECM, plug and plug wires within the past month.

Sometimes when I drive it I get a code 32 - could the EGR have something to do with my randon no-starts?

Scaramanga · 01-19-2006, 06:58 PM

Oh and I can hear the fuel pump prime everytime I turn the key..

maxwedge · 01-19-2006, 08:13 PM

Got strong spark when it won't start, injector pulse?

Scaramanga · 01-19-2006, 08:16 PM

How to do I test to see if it has "strong" spark? I know when it wouldn't crank my buddy tested a plugwire with a screwdriver, and it shocked the hell out of him.. Best/easiest way to check to see if the spark is strong enough?

Scaramanga · 01-19-2006, 08:22 PM

How and how do I test the injector pulse>?

maxwedge · 01-19-2006, 08:27 PM

You can buy a cheap noid lite from a parts house or Napa, disconnect a connector from an injector, plug it in to the connector, crank the engine, if it flashes the pcm is pulsing the injector. Also you could try spraying some carb cleaner into the intake next no start, if it starts it is a fuel related problem.

Scaramanga · 01-19-2006, 08:29 PM

Don't I have to remove the plenum to check the injectors?

maxwedge · 01-19-2006, 08:35 PM

If the injectors are not visible, yes the plenum will have to be removed, so the carb spray will confirm that you are not getting fuel if it starts, if not you are back to probable spark issues.

Scaramanga · 01-19-2006, 08:41 PM

Carb spray and starting fluid are the same right? I will buy some tomorrow...

I just tried to crank it and it shuttered for a sec or less like it was going to start, but then just kept turning over.

maxwedge · 01-19-2006, 08:46 PM

Careful with the starting fluid don't spray to much in the intake and keep your face away from it if someone is cranking it for you. Also locate the pcm under the black box rt fender well, remove the pcm and try tapping it firmly with say a screwdriver handle, see if it starts.

Scaramanga · 01-19-2006, 08:50 PM

PCM is the same as ECM? The computer? I just replaced the computer with one from the chevolet dealership - my other was bad.. I did the tap test on the old one while it was running, and it killed the car.. I didn't do the tap test on the new one yet, but replacing it and the CPS fixed my rough idle.. but still has randon no starts..

richtazz · 01-20-2006, 01:35 PM

To answer your question from a few posts ago, yes an EGR can cause hard starting/no starts and a rough idle. The EGR should be closed when the engine is cold. If it is stuck open, it allows too much air into the engine, leaning out the fuel mixture. It's similar to trying to start an old carbureted engine with the choke stuck wide open.

Scaramanga · 01-21-2006, 01:33 AM

So when the EGR valve sticks open it still won't start with starting fluid then? The car didn't start on me today so I sprayed some starting fluid in the intake... It still just turned over. I waited 1 or 2 mins and it started right up, but after a few secs started running real rough and backfired a few times before it died. I waited a few more minutes and it fired up, idled fine and drove home no problem. I guess I need to replace or try to clean the EGR valve. The valve does have 198,xxx miles on it

GET HEALTHY AFFORDABLE DOG FOOD

DEVELOPED BY THE AUTOMOTIVEFORUMS.COM FOUNDER & THE TOP AMERICAN BULLDOG BREEDER IN THE WORLD THROUGH DECADES OF EXPERIENCE. WE KNOW DOGS.

CONSUMED BY HUNDREDS OF GRAND FUTURE AMERICAN BULLDOGS FOR YEARS.

NOW AVAILABLE TO THE GENERAL PUBLIC FOR THE FIRST TIME

PROPER NUTRITION FOR ALL BREEDS & AGES

POST REPLY TO THIS THREAD