hello. im having trouble getting my car to start. it'll start fine when its cold. after i run it for a few minutes and shut her down, she doesn't like to start back up. if i turn it off, then right back on, its fine, but if it sits for a minute or so, it wont start. i have to use ether starting fluid for it to fire. i looked at the injectors while someone else turned the ignition over, and the problem seems to be that there is no fuel coming out of the injectors until it starts with the starting fluid. after that its fine. any ideas? thanx

 

How many miles are on your car? I'm not sure about F/bodies, but GM's in general whenever they are hard to start when they are hot it is either timing, or you may need a valve job. Whenever I look at a car I always run it till it gets hot then shut it down for a minute or two, then try to restart, if it has a hard time that,s a sure sign of problems. Good luck.

 

Nasty Bird,

You may also not be getting injector flow because of the lack of line pressure. Test your fuel pump relay. If your fuel pump realy is not working, the ECM cannot prime the system for the customary two seconds when the ignition is first turned on. In this case, all pump control would be done with the auxilliary oil pressure switch.

When the engine oil is cold, you will get adequate pressure after the first few revolutions. When the engine is warm, the oil is thinned to the point where normal cranking may not create adequate oil pressure to close the auxilliary switch and energize the pump. Once you have the engine started briefly by applying starting fluid, engine RPM is adequate to make pressure and operate the pump switch. This is further evidenced by the ability to restart right after shutting down, since the line pressure would not have bled off yet. After a few minutes of sitting, fuel pressure can bleed off and prevent any injector flow.

It's also possible the oil pressure switch is out of spec, but that would be irrellevant if the ECM-controlled fuel pump realy was working properly.

I'll bet you a Coke it's the relay or relay wiring. If I'm right, you should also consider changing your oil to a higher viscosity, since less than 7 PSI while cranking is a sign of poor lubrication. (I hate 5W-anything for engines.)

Just in case I'm buying you a Coke, injector pulses are timed and triggered by the distributor reference pulses. The engine has to be cranking to deliver starting fuel, and the ECM needs to know that. Check your electrical connections to the distributor to make sure they are clean and tight.

 

so what you're saying is that you feel its the fuel pump relay not working, therefore the system doesn't prime itself so there is no fuel in the lines until the engine turns over and the auxilliary switch kicks on, right?

ok. so how do i check the relay?

thanx

 

well i know its not the relay, because i can hear the fuel pump kick on when i turn the key. something is not telling or letting the injectors to spray the fuel into the engine. the car will start with a shot of starter fluid, but shuts itself off when the RPMs drop below 1000. im completely stumped and dont have the $$$ to pay a mechanic. any more ideas?

 

NB,

Where do I send the can? Look at the second part of the post. Check the distributor wiring. Also check the engine grounds (on the intake and back of the heads).

Are you getting any error codes? You should scan the ECM jsut to make sure, even if the MIL isn't turned on. Obviously the ECM is firing the injectors, or the engine wouldn't run when you prime it.

What kinds of modifications have you done, if any? And have you checked the fuel pressure? TPS sensor?

 

current mods are 3" catback exhaust, open air element, and a chip. should i put the stock chip back in? i'll go ahead and check the dist. wiring. i checked the ALDL port and pulled a code 12. the only way i know how to pull codes is to jump ports 5 & 6 on the ALDL, so thats how i got the code 12. as far as i know, that means the ECM and sensors are all working fine, right? as we speak, i have removed the ECM fuse for the hell of it to clear the ECM. thanx alot man. dont worry about the coke. i'm a mountain dew man. i wish you had bet my your car though! later