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Discussion Starter #1
Hey All.

I finally have the Camino off the jackstands. New fuel lines and new brake lines have been installed and she drives and stops.

Now she stalls when she's warm... running lean I'm assuming.

I've been doing some digging and it seems like vacuum leaks are a common issue. I've found the vacuum diagram for a carb engine but not for an EFI one.

I bought a timing light but haven't got around to checking the timing yet and I haven't even peeked under the distributor cap yet.

Plugs are NGK, brand new.

Where's a good place to start looking?

Thanks
 

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Code 44 is Lean exhaust: Check for vacuum leakage at the TBI base gasket, vacuum hoses or the intake manifold gasket. Check the oxygen sensor.


When the code says to check for vacuum leaks consider changing all vacuum hoses. At 30+ years old they tend to harden and crack causing leaks.
double check those plastic lines to the TBI ! those are very brittle just changed all of mine on my 87 4.3L
 

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Discussion Starter #6
@87next2last1, I found the vacuum diagram basically washed out under my hood... but those pictures were very helpful.

I went through every hose and connection and i can't spot any cracks or leaks in the hoses, however i see a missing hose and some things i don't understand.

Following the first picture 87next2last1 posted...
I think i'm missing the Temp sensor, and there's no hose running off the VAC Motor.


Also, on the throttle body, Terminal J is blocked off.


I see a hose running from F to a black box that has an electrical connection. Is this the MAP sensor?


Also, there's a hole in the back of the air cleaner.. I'm assuming this is where the MAF goes but it doesn't look like it... And there's a clamp in there that i don't know anything about.


Also, everything is filthy, what's a good way to clean it?

Thanks
 

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Trouble code 44 is lean oxygen sensor. Can be faulty oxygen sensor circuit. See 87next2last1 circuit description from the GM service manual as posted. The first picture, the missing vacuum hose from the vacuum motor of the air cleaner connects to the temperature sensor which is inside the air cleaner. This vacuum hose is connected to the bottom of the air cleaner where the temperature sensor is. There is two vacuum hoses that connects to the temp.sensor. The one I just stated from the vacuum motor and the other vacuum hose connects to the throttle body where terminal J is blocked off according to your second picture. The third picture is the Map Sensor and that vacuum hose is connected to the back (F)of the throttle body. Lastly, the fourth pictureis the temperature sensor which I said the two vacuum lines is connected at the bottom of the air cleaner. Also, when connecting the vacuum hose from the vacuum motor, there is a check valve (delay valve)between the vacuum motor and the temp.sensor. After you connect the vacuum hoses as describe, disconnect the battery(negative)for a few minutes. Reconnect and start your engine, drive for 5 minutes till the engine warms up. After warms up, see if that code 44 comes back. The delay valve allows vacuum to the vacuum motor and the damper door you can see inside the snorkel of the air cleaner. If that damper door is not shutting off the outside air, you will set the code 44. Be sure the damper door is operative. You can also have a faulty O2. Check your grounds also.
 

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Deputy Director Region 6
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Nice write up Elmeano72

Need to clean the throttle body with throttle body cleaner
I use krud kutter on the motor or use the purple power
can just spray & wipe with rags or
cover up throttle body & distributor, spray cleaner all over & rinse with hose !
 

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Discussion Starter #12
Y'all are awesome thanks so much for the help.

I can't find a source on that delay valve anywhere online, and mine is missing. Also, the Vacuum Diaphragm motor looks pretty crusty and the flap is only supported by a thin wire that was installed by the previous owner - the whole system is in bad shape and I have no idea if it even still functions... Does anyone know a supplier that carries those parts? The local auto parts shops don't have them... JEGS and RockAuto were strikeouts as well.


While i was poking around there, i wanted to inspect the injectors.. doing so i broke the gaskets and one of the o-rings so those are currently on order and I can't try to fire this thing up until at least Monday when the parts get here.

O2 sensor SEEMS ok by visual inspection... The wire isn't touching the manifold and the plug connection is tight.
 

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Hey Brett hope you can join us March 29th & 30th at the Gainesville Get-Togther & 1/4 mile run ! There is a few guys coming from Orlando, maybe you can hook up with them & travel up ? if not for the weekend maybe just Saturday ?

Here is info on the big event !


https://www.elcaminocentral.com/showthread.php?t=241940
 

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Brett make sure all vacuum lines are good. You cannot visualize check the O2 sensor. You can take it to Autozone and they will hook it up to computer and if the oxygen sensor is bad, the computer will detect it.
 

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Discussion Starter #18
Steve, I'm trying to get her running reliably first. Once she's running, i'm taking her to the frame shop to get a professional inspection / opinion. I'm not making any reservations or promises until that point. I definitely owe you a beer though!

Frank, thanks for the part numbers!
 

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Discussion Starter #20
Update:

Put all new gaskets and O-rings into the fuel injectors, cleaned them out a bit with carb cleaner.

I did a deeper check for vacuum leaks and once again found nothing.. the vacuum hoses are very pliable so it seems the person who had it before my aunt replaced them relatively recently.

The car doesn't stall anymore but it does shudder for 5-10 seconds once the idle comes down after it's warm. It does the same thing when slowing to a stop after going over about 30mph (though this might be the transmission).

I put 40 highway miles on her last night and she took it like a champ. The Speedo is off by around 15-20mph.. "55" seems more like 70.

I have an exhaust leak on the driver side again, so i have to double check the torque on the exhaust manifold bolts.

I'm also going to take the O2 sensor to an auto parts store and have it tested because the Service Engine Soon light is still on... though it comes and goes now instead of being constant.


Thanks all for your help. I'm one step closer to my goal.
 
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