Posted this question before but this time I will get more specific. After my 88 pontiac formula 5 speed V6 runs for about 30 minutes and I stop, it will not start right back up. the engine WILL CRANK but will not start. I have to wait about 45 minutes before It will start again. The engine gets warmer then my liking 230 (I have flushed everything). I can take off the air breather and spray starter fluid into the manifold and it will start back up. ANY IDEA
Second problem My oil pressure guage either pegs out or reads zero sometimes when I turn the parking light on the oil light next to the guage will come on at the same time WHATS UP with that??
thanks for any input
Joe

On the oil gauge sounds like you have a bad wire to the oil sender. The oil sender tan wire is the gauge signal. If the wire is grounded the gauge should read 0 psi. 90ohm will give 80psi. An open wire would probaby peg the gauge and probaby turn the light on.

On the starting your problem is not electrical is seems.

What would cause the problem that would be fuel related after a heat soak?
Does it run ok after starting with fluid?
If you have winaldl I'd look at what the CTS and MAT sensors are saying.
You might try disconnnecting the MAT sensor and see if it will start. That will either make the ecm default due to no temp reading or make it think the air is very cold and add more fuel. Could try the same with the CTS but it's harder to get to.

Fierobsessed hit it below. Completely forgot about the fuel pump and oil pressure.

[This message has been edited by Dodgerunner (edited 09-14-2006).]

thanks for the help. Yes the car runs fine after I get it started. What is a heat soak?? where are the sensors you are talking about and why would they cause a problem after the car has been running for awhile?? Also on the Oil guage it now reads zero with the light out the light will come on an stay on until I hit my parking lights Weird. the light will extinguish after awhile. normally the guage stays pegged and the light is on
I have an additional question my fuel guage reads way above full is their an adjustment for that?

Your primary problem is probably the fuel pump relay not working, you may also have low oil pressure, or a bad oil pressure sender. On fiero's the oil pressure sender is a backup fail safe incase the fuel pump relay craps out. However, when the engine is warm and off, cranking the engine may not be enough to produce the oil pressure necessary to kick on the fuel pump, thus it will never start. First thing to do is confirm that the fuel pump relay does infact deliver a 2 or 3 second prime when the ignition is first switched on. If it doesn't, fix that problem first. And the non start while hot will be fixed as well. Otherwise, either your oil pressure is too low to let the pressure sender switch the oil pump, or the pressure sender is damaged... that's a whole nother game.

Have you tried any of the things suggested in your other thread? You haven't posted anything to indicate that you have. Do you have fuel pressure during a no-start? Do you have spark during a no-start? People are trying to help. Are you listening?

Okay trying to go over everything. I purchased a new oil pressure sender and will replace it today. How do I know if I am getting the 2-3 second fuel prime? will I hear a buzzing sound? Also from the other thread how do I check the fuel pressure? there was also mention about taking a wire to the aldl I have no idea what that is. Didnt realize Oil pressure would affect the fuel pump but of course i really don't know if I have low Oil pressure either because the guage doesnt work properly as I have posted. It will peg out or read zero whenever i start the car.thanks for your input. Just couldnt find my other thread as so many people post on here
And yes i am Listening I just was not able to find my posted thread as so many people post questions. it was buried.
Fairly new to the forum i appreciate everyones help.

quote Originally posted by racer778: Okay trying to go over everything. I purchased a new oil pressure sender and will replace it today. How do I know if I am getting the 2-3 second fuel prime? will I hear a buzzing sound? Also from the other thread how do I check the fuel pressure? there was also mention about taking a wire to the aldl I have no idea what that is. Didnt realize Oil pressure would affect the fuel pump but of course i really don't know if I have low Oil pressure either because the guage doesnt work properly as I have posted. It will peg out or read zero whenever i start the car.thanks for your input. Just couldnt find my other thread as so many people post on here And yes i am Listening I just was not able to find my posted thread as so many people post questions. it was buried. Fairly new to the forum i appreciate everyones help.

Yes --turn the key on (only ) listen for the 3 second buzz. You`ll need a fuel pressure gauge, all auto parts stores will carry them, you`ll be hooking it up to your schrader vavle, which is on top of the fuel rail, look over by your battery, you`ll see 2 hard fuel lines come up, then disapear (allmost) under your top plentum ( big red sucker that says Fiero on top) . You`ll see what looks like a big silver vavle stem, take the cap off and hook up your fuel pressure gauge, then key on and take the readings, then start the engine, take the readings, blip the gas pedal take the readings. Aldl connector is a diognostic plug, thats behind the cigg lighter panel in your center consol. You`ll need a t-15 torx to get the 2 panel screws out--you`ll see it then. Winaldl is a free program that Dodgerunner is talking about--you can read more in the links below about it, Marvin McInnis has your thread cleverly conceled under OTHER THREAD ? in yellow above,I`ll put it below also. Start with the above mentioned --and ask as you go along --we`ll try to get you going again--if your questions start to get buried --just BUMP your-self back to the top--(re-post on the same thread) --like this will hit top again... The forum is like a fast merry-go-run, jump on anytime you need to and Welcome to the forum....
http://winaldl.joby.se/
https://www.fiero.nl/forum/Forum2/HTML/076257.html

Harbor Freight has an inexpensive fuel pressure gauge that will work just fine. They occasionally have it on for $8.

Just to expound on about the 3 sec thing.

When you turn on the key for the first time the fuel pump under the middle of the car is run by the computer(ecm) for 3 sec. The ecm turns on the fuel pump relay located by the air cleaner.
You can put you ear on the console and hear it (it's usually loud enough you don't have to)
If you cycle the key on and off a couple times it does not do it every time but the first time after setting a few min. should.
If you don't hear the pump run then your car will not start until there is fuel pressure.

There is a backup to fuel pump relay thru the oil pressure switch. When the oil pressure reached a set amount the OP switch closes and keep the pump turned on. If your relay or ecm is failing and not running the pump the engine will not have fuel until there is enough oil pressure to start the pump. That might be why when you start the engine with some starting fluid it keeps runnng. The oil pressure comes up enough to start the fuel pump and you keep running.

If this is happening when the engine is hot then you need to figure out if it is the relay or ecm.

Make since?

[This message has been edited by Dodgerunner (edited 09-14-2006).]

thanks for all the input I will buy the guage (handy to have) and see what happens. I'll post and let you know. As far as the fuel guage is there an adjustment because the guage always reads WAY high?
Also anyone know what forum to go to get answers on a 1989 Pontiac TA (GTA) tuned port injection 305 It will not idle under 1000 rpm. Only thing we did was change the radiator. Can't find a vacuum leak cleaned around the MAF sensor plugs wires good

On the 89 I'd check the Idle air motor.

On the fuel gauge there is some adjustment but you have to pull the tank to do it.

If you temp gauge pegs when you turn on the key there is also a fix for that.
http://www.fierosails.com/tempgage.html

okay so far I do hear the BUZZ sound from the fuel pump when I start it I can drive for a few minutes stop get out come back and it will start I ran around at lunch only running for a few minutes at a time and the car starts fine. It is when I am running for an extended amount of time that the car will not start up. I figure it has to be something with the heat. heat could be causing the low oil pressure ? Dodgerunner you mentioned Idle air MOTOR not exactly sure what that is are you talking about the idle air control for the 89 TA??

The fix for the fuel gauge being off (not pegging) the 1/4 tank empty thing, then reads over full is here.
http://www.fieropride.com/tech/gas_guage.htm