rocmemphis

Been having problems with the car here lately. Scanned all weekend and this is what I came up with.....(all in Cell 16 at idle)

MAF: 12-13 g/s
MAP: 50 kPa
BAR: 104 kPa
IAC counts: 70 - 90
02 readings seem to be in a good range
LTFT bank 1: 108
LTFT bank 2: 125
ticking really loud now
2-5 degrees of knock retard at WOT
oil smelled like gas last time I changed it

What I have done to try and reconcile this...

1. cleaned MAF
2. cleaned TB and IAC
3. replaced exhaust manifold gaskets and made sure no leaks exist
4. fuel pressure 45 key on, 41 car on, pressure does not bleed down when turned off
5. vacuum 14-15" Hg
6. no fuel in FPR vacuum line
7. adjusted rockers to 1/2 past lash and 3/4 past lash
8. replaced pushrods

Someone please give me some ideas. I am going to start pulling the engine apart this afternoon.

OBE1 95Z28

Let us know what mods you have. I take it you're got a cam because your vacuum is low for stock. Fuel pressure sounds high too. Could the ticking be coming from a bad wire (arcing to the exhaust)?

rocmemphis

Mods are:

LT4 Hotcam
MAC headers
1.6 CC Pro Mags
Crane 10308 spring kit
PCMforLess tuning

Plugs and wires are brand new. Changed them out first when I started having problems.

Injuneer

What does it idle at? The MAF gps looks like its at least 1,000rpm. Has your MAF sensor been ported?

Left side of the engine obviously has a problem... 108 BLM indicates the PCM is detecting a rich condition and has reduced the fuel as far as it can, and probably still can not control A/F ratio. If its really rich, you could be washing down the cylinder walls with excess fuel, and getting fuel into the oil.

Fuel pressure appears OK. At idle, no vacuum connected, should be in the range 41-47psi.

Have you checked the EEC purge line for wet fuel, or solenoid stuck open? Have you pulled the injectors and looked for a leaker? When you have excess fuel dripping it will pass through the combustion process, and consume the little bit of O2 exiting the other cylinders, and create a "false rich", forcing the PCM to respond as yours has with a reduced BLM. But I doubt that's the case if you actually smell fuel in the oil.... its probably a "true rich" condition.

Have you listened with a stethescope to try and pinpoint the source of the tick?

importeater

What do the spark plugs say? What kind of tick is it (lifter, valve, header leak, wire arching)?

rocmemphis

It really is a different type of tick than I have ever heard. I thought it was an exhaust leak until I replaced the manifold gaskets and it didnt go away. It is RPM related and never goes away. The spark plug prongs where white when I pulled them on bank 1 which is supposedly a lean condition issue.

I am stuck on this one.
Is it possible that the valve springs walking could cause a loud tick???

rocmemphis

MAF is descreened but not ported. Idle in park is 850. Idle in gear is 775.

grumpygreaseape

what were the initial symptoms that made you notice enough was wrong to scan it? the ticking? is it misfiring, or idling as if its down a cylinder? did you burn\chip a valve or seat? whoever said busted spring has also given a feasible cause. if a burned\hung\damaged valve is causing problems it would induce o2 in the exhaust and the pcm would do what its doing. exhaust side.

rocmemphis

Well after I got the ECM from PCMforLess it ran like a champ for about a week. After that I kept hearing a ticking noise I thought was an exhaust leak. It got increasingly loud until I decided to readjust the valves and change out the exhaust gaskets. Nothing worked and when I hooked up my scanner to the car I got the readings listed above. Currently I am pulling all the valve springs and replacing the seats with CC 4770 seats b/c I have been reading that the 10380 kit seats are crap.

I checked the injectors and FPR and there are no problems there.

Thanks for everyone's help. Any other ideas guys?