i have a 88 firebird that has an issue..when you start it it will run about 10 sec and shut off..i have replace the injectors ,fuel pressure regulator,rebuilt the dist,and put a hotter coil and still does the same thing..it is a 2.8 mpfi and also has a new fuel pump ..gets fuel to it please help out if you can thanks

 

Is it cold where your at? If so maybe you could try a heated o2 sensor, or vacuum leak???

 

Have you replaced your fuel filter??? I had a truck one time that would run for about 20 seconds or so, then start sputtering and die. If you tried to take off in it it would die. The fuel filter was clogged up enough that the thing wasn't getting enough fuel to keep it going for very long. When it sat a while,though, enough fuel would seep through the filter to make it run for just a little while.

I am sure that you have already changed this, though.

Also, your catalytic converter could be plugged up really badly.

 

i have changed the filter in it..and to the other answer i live in louisiana not too cold in these parts..today i put another ecu in it still no good ..has to be the vacuum lines.my other firebird has a 383 in it and its no help when it comes to vacuum lines..as far as cat back system i'm running straight pipes on it

 

if anyone has a vacuum diagram please post it i need to get this car going again or take pics of a running 2.8 and i can look at those

 

This is the one off of my 87... Might be a little different for your car depending on options, but it will get you started.

BTW, my engine used to have a large black pipe, running from the nipple at the back of the intake where the PCV valve line connects to, running to a similar nipple on the throttle body. It is shown in the diagram as also running to the purge port on the vapor canister through a smaller line. I doubt yours will have this, so you will need to T into the nipple at the back of your upper plenum like I have to now.

:edit: Although, it seems as though you have a different problem on your hands. Usually, with a bad vacuum leak, you can pretty much forget about the engine even running for that long. Have you tried disconnecting your MAF sensor and seeing if the engine runs any better?

 

i see what you are talking about mine already has the t on the upper plen..i can hear it sucking air but with out 2 people it is hard to do ..do you think the smog junk might have anything to do with it..my line routing looks just like the pic ...in more advice..

 

ok i got my 2.8 to idle now when i pres the gas it shuts off unless i flutter the gas peddle.what would cause this..also my oil pressure gauge shows no pressure ..i did remove the dist when i rebuilt it..do i need to take it back out and double check the rod on bottom of dist..but i can feel oil on rocker arm ..

 

To answer your first question, if you don't have 2 people, you can block the wheels and stick a coin between the idle stop screw and the throttle plate arm at the top of the TB to increase your engine's speed while you are hunting for that vacuum leak you obviously have. Use anything flammable (except spray paint) and spray around lines and hoses to find your leak. If the engine runs smoother when a spot is sprayed, that would be a leak.

As for the gauge, you may have disconnected the oil pressure sender at the filter. It has a white wire attached to it. Unless the engine is making a real racket while running because it obviously doesn't have oil pressure, you don't really have much of a problem because our old gauges are known to be inaccurate anyways. However, since the rockers and valves are the last thing to receive any sort of pressurized oil, I wouldn't worry too much about your engine's oil pressure.

 

Check the Maf sensor, that what it sounds like to me

 

That's another thought. Have you held the throttle around 2000 RPM for about five minutes or until the temp gauge reads over 100? If you have, and you let go of the pedal, does the engine behave? If it does, your MAF is a suspect. However, if you hold the gas and the engine surges, you still have a vacuum leak (a large one... small one won't do this).

 

Yeah try unplugging you MAF, if it stays running thats your problem

 

i have it idleing now ,,found a wire undone on back of fuse box to the ecu..now it has a back firing problem when it gets over 1500 rpm backfires through the exaustall vacuum lines are now connected

 

just checked the maf 1st unpluged it car still ran the same..brought maf in and got a flashlight and looked in it the resistor on the connection side that is on the board is burnt..guess what that means

 

... That it's time for you to shell out $80 for a new one with a lifetime warranty.

 

i guess so but gonna be a few before i can afford one ..wife is only one working right now i'm still trinying to find work