Stumped

[larrym]

So had the car out testing the new seats got on it a bit when I was cruising back home noticed it was really lean and stumbling coming to a stop symptoms of a large vacuum leak drove  home popped the hood and grabbed my stethoscope nothing obvious hmmm did a smoke test still nothing swapped the pcv no change. Compression test 5 at 150 # 5 at 135 that might account for the boost flutter. When you fire it up cold it fat idles good until it gets to temp then lean and rough. Tried another narrow band no change the part that really confused me is that there is very little change in the IAC it's right around 15 TPS is good too. My BLM has climbed from 120 at idle to 129.

[TexasT]

Fuel pressure?
Did you put fuel in recently, like right before this happened?

[larrym]

Fuel pressure is  good pump is new last year

[larrym]

Hmmm I fuel up  but I drove it an hour and a half and it appeared fine I will dump a gallon of methyl hydrate in it  see if that smartens it up

[daveismissing]

EGR?

[larrym]

It's blocked no leak I could hear with the stethoscope or carb cleaner

[gusszgs]

Vac at idle? Any change?

[larrym]

Vacuum is at 12 seems low  blocked the TB and and smoked it again......... a lot pulled the pcv and the breathers no smoke anywhere.
Checked the slack in the timing chain 8 degrees it's sloppy wonder if it jumped I guess it's time to put it on a stand. 

[larrym]

So it's on a stand I pulled the rockers and smoked it again nothing.... Pressurized the intake it holds pressured it there is no obvious leak it does leak down eventually but it takes a while you would think with the way it was running it had a large leak....
Front cover comes off tonight.

[larrym]

Well I think I found my problem it appears # 5 exhaust valve is bent or burnt it's not sealing that's why the compression was down on that hole charged the cylinders with compressed air it's spewing out the exhaust rapped the valve a couple times with a hammer no change the heads where machined last years new guides and springs oh well cost of playing I guess.

[larrym]

Well I pulled the intake look what I found. This cylinder had 150 compression and it did not huff out the breather it leaked less than #5 and the leaky valve so a new set of head gaskets and I'm going to try and lap that valve into submission it looks like it's been leaking a while I would take it back to the shop but I'm starting to lose faith. There is a head shop a couple hours away I have heard good things about.

[good2win22]

Damn the luck

[larrym]

It's actually kind of lucky no graphite in the pan the next time I hit I would have made a mess

[larrym]

Well this is disappointing looks like a single angle valve grind. I spent a lot getting these set up and don't really feel like putting another 300 dollars into them.

[larrym]

My heads are on and double checked the chain with a piston stop. and a degree wheel it's out a degree retarded it's installed 4 degrees advanced so I figure it's 3 degrees advance after it stretches 2.