Ok I just got done doing the intake manifold leak fix...in addition to that I have
New Opti
New O2's
less than year old Battery and 170 amp Alternator
New belt
Cleaned IAC and Throttle Body/MAF
Fuel filter less than year old
Coil less than 8 months old
Plugs/wires about 4k miles

Problem is that I have the same problem ive been having for a LONG time. When I come to a complete stop IN GEAR(Auto) and stay there for about 5+ seconds, the RPMS start to drop, and the voltage gauge sstarts to drop slowly(kinda eratically)...the RPMS go from like 950-1000...all the way down to around 550.

I got a code-44...says Left O2 is running lean. My scanmaster is showing the LB Learn going up to like 160 and fluctuating...also the LP is higher. The LO2 was about 2 months old, so I took it out and put in an older one. Since then the SES light hasnt come on yet, but it still runs crappy. When I first turn on the car it'll sputter and spit some, then it'll warm up and be ok...until it gets to running temp, then SOMETIMES it'll just shake like it wants to come out of the motormounts. My EGR and CAT is removed. Scanmaster is showing my Vacuum is fine...BAR is 30 and MAP is 10 so=20.

Like I said I have a scanmaster...I know how to use it alright, but if you guys have a secret that will help me really pinpoint my problem, let me know please. Ive spent too much damn money, and still cant fix this.

Thanks for any help!

 

I'm wondering 2 ways. What temperature does the ECM report after warm up? The other is, does the fuel pressure hold after the engine is shut down? When was the last time you had the fuel injectors cleaned the right way?

Oh yeah, while this is going on during idling, what are the IAC counts doing?

 

At idle, the IAC counts drop down all the way to 10. They're supposed to be at 20 to 40 or so right? SO I know those are too low.

Ive never had the injectors actually cleaned. Ive ran some Lucas Fuel injector cleaner stuff thru the system many times, but not recently.

Im not sure about the temp the ECM reports after warm up, what do you mean by that?

Thanks for the reply...

 

There are 2 temp. sensors. One for the gage and the other for the ECM. If the ecm sees a lower temperature cause the sensor is bad, it will think the engine is cold and richen the mixture. But I believe I'm leading you in the wrong direction. If your idle is dropping and the IAC counts are dropping that's an entirely different issue.

I believe a vacuum leak would increase IAC counts. So try this. Get to the IAC connection as soon as the engine is idling at a good level and before it starts to drop. Unplug the IAC and see what happens to the idle. You may want to excercise the IAC manually with the scanner to see what the idle does.

An interesting point is the PCV system can have a bad effect on the idle and the IAC if it is malfunctioning. You may want to check it also.

 

well I unplugged the IAC and THEN started the motor..it was idling high at 1400 RPM..but when I would give it some gas, it would rev up really rough, then go back to 1400. Ill try warming it up first and unplugging the IAC tomrrow...its too late right now.

Any other ideas? Most of the damn engine is replaced and theres no vacuum leak...

 

I think if you have a vaccum leak then i believe that would drop the IAC count. With the vaccum leak the engine is getting enough air it doesn't need the IAC. I would look for a vaccum leak.

 

If you didnt block off the EGR correctly that can cause a vacuum leak, also you said that you just recently fixed your intake manifold leak..... Did you seal everything back up correctly??

 

The EGR has been blocked for years...so thats nothing new...also, my scanmaster is showing that the vacuum at idle is 20....i subtracted the BAR from MAP(30-10)....so doesn that mean I dont have a vacuum leak?

And yes ive doubled checked all the vacuum lines and made sure they're all on there.

One quick question....can you have a vacuum leak thru the Oil Dipstick? Mine is loose and moves and..I need to get under there and try to tighten it or something, but I think there is oil coming out from where it screws into the block...could that mess up something?

 

Well I jes drove the car a bit, and when i got back home i let the car idle IN GEAR..then I looked thru the scanmaster and noticed my MAP reading was around 13, give or take .5.....My Bar was like 30.4, so would this indicate a vacuum leak when the car gets warmed up? cause Map is right at 10 when I just start the car cold.

Would a Header leak cause this? I think I hear something that sounds like air escaping from the engine, sounds like it would be a header leak...which is why it only happens after the car is warm?

But that still doesnt explain why the car is running a bit rough when its cold...

 

What do yall think...my sound like an exhaust leak possibly? Anyway to track that down with the scanmaster?

 

Yea, I would check to see if you have any exhaust leaks on the side that says you are running lean. When I had my fuel injected motor in my car, I had a similar problem and I ended up having to replace my header gaskets and my collecter gaskets to fix the problem. Hope everything works out for ya.

 

is the header leak and the lean o2 sensor on the same side of the motor?

 

theres actually a lil tick on both sides of the engine, but the side its louder on is NOT the lean O2 side...I think its the rocker arms clanking on the one side..but they've always done that..