badly missing / barley running 1998 2.8 30V

[bfreehill]

badly missing / barley running 98 2.8 30
its a 5 spd car with 146k, was running great then went down hill fast.

I started with plugs, then plug wires. no help.
tried 3 different coil packs, no different.

cleaned the mass air flow sensor and it ran good for about 30 seconds than back to missing bad.
runs the same plugged in or not.

did a compression check , all good.

any thoughts?
bad mass?

thanks,
B

[koidragon1980]

badly missing / barley running 98 2.8 30
its a 5 spd car with 146k, was running great then went down hill fast.

I started with plugs, then plug wires. no help.
tried 3 different coil packs, no different.

cleaned the mass air flow sensor and it ran good for about 30 seconds than back to missing bad.
runs the same plugged in or not.

did a compression check , all good.

any thoughts?
bad mass?

thanks,
B

could be a bad MAF sensor if it runs the same plugged in or not. any CEL? get it scanned anyway and research any codes you find.

any other work done recently that was unrelated to the issue?

post any codes you get from the scan and take it from there.

[bfreehill]

I pulled PO302 misfire code but nothing else.

With VAG-Com I observed misfires at idle on plug one,
above 3000 rpm the misfire jumps around randomly to other plugs.

[koidragon1980]

read through this thread: http://www.passatworld.com/forums/68...e-insight.html

there a couple of ideas in there for you. if you use the google custom search bar on the passatworld site and search for "P0302 v6", you'll find more info and suggestions.

[bfreehill]

great thread, thanks for the link.
tried my purge valve plug but no difference.
however I also tried my mass again and it runs better without, and kinda drivable.
this time got PO304, mis-fire on #4

but in general its running better today, so weird.

may remove my EGR and see if I can clean it, do the fuel filter, and do a little dance.

[koidragon1980]

great thread, thanks for the link.
tried my purge valve plug but no difference.
however I also tried my mass again and it runs better without, and kinda drivable.
this time got PO304, mis-fire on #4

but in general its running better today, so weird.

may remove my EGR and see if I can clean it, do the fuel filter, and do a little dance.

if it feels better without the MAF, then i'd definitely replace that sensor as well. running without a MAF should be causing things to get worse, not better.

[tryin2vw]

Have you checked the vacuum hoses?

[bfreehill]

So it was my fuel pump intermittently going out.
replaced the pump, put the original coil pack and mas back on & all seems good.