Ihave no idea what is wrong now.... It was fine...Now I went to start it after a week of not driving it and it just tried and fired over for a mila secong and that was all she wrote.... I tried and tried and nothing but the same thing.. it trys for 2 attempts and then it will just crank and crank....I can se when cranking I have oil presure and when not cranking I have any where from 4 to 8 PSI for oil presure... I am at a loss....

I hope you good people can help me here....
Thanks in advance for it..... :mad :cuss :confused:

 

You need to determine if your getting fuel & spark.
Spray some starting fluid in the intake tube,if it fires your not getting gas.
If it doesnt make any difference then mabey no spark.
Check coil & module.

 

hit it with some carb cleaner or either if it does not start then you are not getting spark, check the coil if it does start then you have a fuel issue.
I had the same problem ended up being the coil and spark plugs

 

Measure the fuel pressure in your fuel rail. Use your timing light to see if you have spark and at the right time. Put a low power 12v lamp on one of your injector plugs and crank the engine and see if the injectors are being pulsed.
Remove the flexible tube on the MAF to ensure the engine is getting air.

 

I can smell fuel when I am cranking it and when it tries to fire over....I will hit it with the starter fluid in the morning.... Where is the module at? I can't figure out why it's acting up...makes no sense to me.... It was fine...I just got it out of the paint shop 2 weeks ago and have been putting new carpet and stuff inside so I have not drove it...When I drove it home from the paint shop it must have died 5 or 6 time s on the way home and the fact it drove like crap all the way home....I figured it was due to the battery being unhooked and the computer trying to learn again... I went ahead and put in a new battery and fired it off and it was a little rough, surging, and what not, for about 20 mins, and then smoothed out , keep in mind I was not driving it then, it was setting in the driveway and I had the AC on full, I just wanted to blow all the crap from the paint shop out of everywhere....dust and all...after that I have not started it again until today( or tried too anyway)... .it has done this before a couple of times...and then it starts and acts like nothing ever happened...runs perfect..No codes or anything...today it just decided to do it again..but still no codes...I don't get it.... I have to fix it for sure this weekend...It's killing me not to be able to drive it...I have to ride to work in my wifes Saturn....YUCK....I just duck down in the seat so no one can see me... :lol: :lol:

Please keep your thoughts and help flowing my way and thanks

 

pull a sparkplug lay it on the manifold turn over the engine and see if the plug is hot make shure the plug is grounded if you have spark then your not getting fuel try the starter fluid thing the best way to do this is the remove the intake hose on the backside if the MAF since the wires on the MAF are sensitive to moisture Ps. WHEN WAS THE LAST TIME YOU CHANGED YOUR FUEL FILTER???????????? :flag :grouphug:

 

Whenever you are troubleshooting a car, NEVER make assumptions that the new parts or previous repair is NOT involved!!! Keep an open mind and test for everything that can cause the symptoms and THEN decide what the cause is. Now go back and read my previous post and follow the recommendations, you will have a better chance of finding the culprit.

 

OK, car still wont start or should I say stay running.... I check for spark the ole fashion way, and I have great spark.... I then checked for the injector pulse...I put a test light in at the injector while cranking the car and It lit up like it should... I then pulled the intake hose off the TB and shot some starting fluid in there and it fire right off.... But of corse died.... I did not get a chance to check the fuel presure yet as I did not have a presure gauge...Could it be a sensor or something... I changed my fuel filter less than 6 months ago, and the plugs are less than 6 months old( and not cheap ones).. I am at a loss....What about the fuel pump or fuel pump relay, or ??????.....

Thanks guys for the help....What are your next thoughts. By the way I checked to see if I was getting fuel at the rail by seeing if anything came out of the shrader valve, not much did and was not much pressure there...it was a split second of a small amout of fuel and then nothing... I have new FMS 24 lb injectors that were done a little over a year ago....

:banghead:

 

Even by your own crude fuel pressure test, you have insufficient fuel pressure. Either you aren't getting 2 seconds of fuel pump run time when you crank the engine, or you have a leaky injector that prevents starting because the fuel pressure bleeds off quickly. A fuel pressure gauge will tell if you have a leaky injector. Turn your ign sw to run for more than 2 seconds and then off. Watch your fuel pressure gauge, GM says if it loses more than 1 psi in 30 minutes you have one or more leaky injectors.

 

Could it be a weak fuel pump?.... I know My injectors are good....It's something else related to fuel....maybe I should just get a new pump and filter...I can hear the fuel pump come on when I turn the key for that 2 seconds though...that was one of the 1st things I listened for....this is really starting to get to me...I feel like an idiot....I am lost .... :mad I have to be missing something.....

 

Quote: I know My injectors are good
--------------------------------------------------

How do you know your injectors are good? Are you pyschic? Borrow or buy a fuel pressure gauge and do the leakdown test I described. THEN and only THEN will you know if one or more leaky fuel injectors are preventing your engine from starting. If you don't want to take anyones suggestions for finding your no-start problem, then why do you bother to post here? You will never find your problem when you eliminate possible causes out of hand without testing and proving that your supposition is or is not correct.
And...yes it could be a weak fuel pump or check valve or clogged fuel filter.
Test for all of these possibilities and either eliminate them or find the problem , then you won't be lost.


[Modified by jfb, 10:21 PM 3/14/2003]

 

I know they are good , do to when the car started acting up at the begining of the last month that was onr of the 1st things I check. At that time my neighbor had a presure gauge to do the test with...I have not seen him latlely... I will get a presure gauge in the morning a do it ...What is a check valve and where is it located on the car...I saw your post on the other guys , about his car not starting either...mine was doing the exact same thing as I discribed in my 1st post on this subject... Where is the fuel pump relay and oil presure switch located on the car?

I'm sorry if I pissed you off...I'm getting very frustrated with myself right now over the car, as I have put so much money in it in the past month with new paint and interior...and now I can't even enjoy the new look...

Again thanks for the help I am going step by step as you discribe...Except the presure test , but I will do it in the morning to rule that in or out...

 

You didn't hack me off! :D I understand the frustration of not finding the problem with your car, I've been there. Good mechanics take nothing for granted, and think of all the logical things that could cause their symptoms and test each item, even if they replaced the blahblahblah yesterday. Yesterday doesn't count, the problem is today and today is when you prove by testing if the component under suspicion is or is not defective.
Fuel pumps have check valves so gasoline under pressure won't drain back to the gas tank. C4's run the fuel pump for 2 seconds during cranking and if the engine starts, the rising oil pressure turns the fuel pump on . The oil pressure switch is on the LH rear of the engine on the oil pressure sender. Don't get discouraged, check everything and don't give up! Good luck tomorrow.

 

jfb. I have been following the discussion and I am having an almost similar problem. Posted last week that I changed the intake, plenum and runners. Tried to start the car and it would not fire up. Checked the fuel pressure and nothing. No pressure at all. Just changed the diaphragm in the fuel regulator and I got a little fuel through the Schrader valve but I still get no reading on the pressure gauge. My question is when you have the gauge on the valve and you turn the ignition on, will the pressure gauge indicate some pressure or do you have to have the motor running to get a pressure reading. I get nothing with the ignition on and when the engine fires for a few seconds when I hit the key, I still get nothing on the gauge. The needle does not move at all. I suspect it is a fuel problem but I am not certain how to diagnose the problem with no fuel pressure. Any help you can provide will be greatly appreciated.


[Modified by BillV, 12:12 AM 3/15/2003]

 

I had the same problem, One day it started / next day would only crank and crank. I did a search on the forum and found the following suggestion.

1: Turn on ign for 2 seconds then turn off (do not crank) You should hear the fuel pump run.
2: Wait 10 seconds then try to start with gas pedal half way down.

She turned right over, took her to mech. and had pressure reg replace....

Don't know if this is your problem, hope it helps...

John

 

BillV, no fuel pressure has a lot of potential causes. You can eliminate a defective motor on the fuel pump by jumping 12v to the fuel pump fuse. If the fuel pump motor ground is good, then the fuel pump should run and you should observe fuel pressure. The fuel filter could be clogged not allowing fuel flow. The fuel pump relay could be defective, jump 12v to the grn/wh wire on the relay and observe if the relay closes and the fuel pump runs. The black ground wire on the fuel pump relay does not go to ground (it should). Measure the resistance of the black wire to ground (should be less than 0.5 ohms).
The fuel pressure regulator is defective. No fuel in the gas tank. Fuel pump fuse blown or making poor connection to the fuse clips. Hope this helps.
And yes, fuel pressure should occur when turning the ignition to run,


[Modified by jfb, 10:05 PM 3/15/2003]

 

Update on my car... It's not been a good day...car still wont start..I checked the spark to see if it was in time with the timing light and it was .I changed the oil presure switch, fuel pump relay and fuel filter...still will not start... I did the jumper wire to see if the pump was running and it was...I did not get a fuel pressure gauge yet as everywhere I went today was out....just my luck...But if I just spray some startign fluid in the iTB, if will start just fine, but then die in a few seconds.... Could this be a week fuel pump.... I even put the seats back in and pluged them in to see if that would do anything, they have been out of the car as I was redueing the inside of the car... but still nothing...I give up :banghead: ..I am missing something something ....BUT WHAT.....

 

Here is a hunch and I am not sure of the ground path to the pump. YOu said it ran like crap when you got it back from the painters. If the fuel pump is grounded on the frame in the back - the connection might be bad. You can test that by unhooking the power to the fuel pump and powering it with a battery charger long enough to test and see if it will start.

 

A pump can run & not pump fuel.
Just because you hear it, doesnt mean its pumping.
I'd change the pump.

 

You are missing a fuel pressure gauge, your car is fuel starved or running WAY too rich. If you have inadequite fuel pressure then you need to find out why (bad fuel pump, bad fuel pressure regulator, stuck open injector). Open the fuel line and connect a rubber hose to a jar and turn on the fuel pump for a short duration and determine if it is pumping fuel. Don't get discouraged and keep shopping for a fuel pressure gauge.
Check the fuel level in the gas tank, the paint shop may have run it out.


[Modified by jfb, 10:13 PM 3/15/2003]