lt1 starts and dies right away, runs ok after it starts

[Craig 94 TA GT]

You got the new fuel pump in but have you checked pressure yet? Pressure at key on, idle, WOT, and after shut off to see any leakage?

[Trans Am]

ok, injectors not leaking , i lifted the fuel ramp and its ok , not dripping at all, same issue
I dont have a tester yet , nor fuel pressure gauge

[Joe 1320]

Does unplugging the MAF still cause the car to run perfectly?

[Trans Am]

Does unplugging the MAF still cause the car to run perfectly?

yes, it runs ok with the MAF unplugged , havent tried to start it up with it unplugged but last time i tried it started ok every time, just fans on and check engine light on .

Starts and dies sometimes , and sometimes runs rough for a few seconds , about 10 20 secs, then all of a sudden its ok, smooth . When i unplug the maf while it is running it revs up to about 1000 rpm at idle then drops to normal idele after a few seconds. Exhaust smells funny, not very rich, but it clears when the engine runs ok, its like a bad rich smell and fumes like caused by misfires i think. no smoke though, not even at wot

[Trans Am]

ok, yesterday the hose from the passenger side AIR check valve came off , and hot exhaust gases were blowing from the valve almost melted the wiring loom . air fuse under the hood was blown too , and some foam looking black stuff was stuck in the maf screen ( like pieces from a dried and broken sponge) which i think came from inside the secondary air pump. i noticed that once a long time ago and cleaned it and was ok till now.

if exhaust is blowing through the valve means the valve is bad i suppose, a good excuse to get rid of the air system. and the cat. haha
anyway , car seems to start better, i will drive it to work tomorrow and see what happens

Is the secondary air system in any way linked to the egr system ? was thinking it might have affected the egr causing the bad start ups

[Injuneer]

As I recall, this thread is about your 95. If so, there is no connection between the AIR and EGR systems. Only the 93 has the two connected.

[Trans Am]

ok...changed the plugs, the opti...same issue .
i am suspecting something is wrong with the egr, the car ran very badly, no power , not running , overheating - plugged cat ...i put a de cat pipe and now it runs almost ok, a slight miss though.

The plugged cat caused one of the air check valves to break and allow exhaust gases into the air pump and intake .
What would a sticking egs valve cause?

[Injuneer]

EGR stuck closed won't affect the way the engine runs. Stuck open its going to idle very poorly and likely stall, continue to run rough until you operate the engine in the range that the EGR valve would normally be open.

[Trans Am]

EGR stuck closed won't affect the way the engine runs. Stuck open its going to idle very poorly and likely stall, continue to run rough until you operate the engine in the range that the EGR valve would normally be open.

if i disconnect the vacuum line from the egr solenoid to the egr valve it should remain closed ?
should the engine start and run ok with the egr valve closed?

[dochidalgo]

If the accuator selenoid is faulty you'll get a DTC
If the EGR valve is half way open or closed, you won't get a DTC. That is due the valve stem is nor run properly because the charcoal. In closed loop the EGR must be closed, if not, you'll have idle and performance problems.

Yu want to uninstall it, cleaned and asure the valve stem runs properly. No big deal. Let a mirror guide your steps.

Good luck mate

dochidalgo

Oh, the engine start with a faulty EGR or closed in open loop will give you hard starts.

[Trans Am]

Thanks Dochidalgo,
I took the EGR valve off and cleaned it, stem moves ok , moves when vacuum is applied , all seems ok, but the problem is still there ..still hard to start, runs really bad and shaking , then after a little while everything is ok , revs up to like 1200 revs and goes down to correct idle speed , everything ok afterwards, car pulls strong ( strong enough to break another transmission mount lol )
Any ideas?

[Trans Am]

ok, i installed an egr block off plate, still the same problem

what happens if the oxygen sensors go bad? if i unplug them , will the car run ?
sticking valve?

this is very weird...only runs rough , and shaking really bad like the timing is off, like running on like 5 cylinders ....only for about 10 seconds, then ok ?!!!??!!!! funny smell too, from misfires i think

cant think of something else....does the same with maf disconnected,

[Trans Am]

ok, its a faulty ignition switch