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Topic: Vaspooge issues 87 T bird 3.8 (Read 2701 times) previous topic - next topic

Vaspooge issues 87 T bird 3.8

I am not sure why the air recirculation door under the glove box is not working I believe lack of vaspooge.
Also without using a vaspooge gage I do not believe I have vaspooge at EGR  valve.
 Any help is appreciated
              Doug

Vaspooge issues 87 T bird 3.8

Reply #1
on your car, all interior hvac controls are sourced from one small line as follows.


your storage vac container is located under the passenger fender.

-the engine runs
-the vac tree by the brake booster has one particular small black vac line you should focus on.
-this black line travels from the driver to passenger side and arrives at a 3way check valve.
-one branch leads out to the vac storage container under the pass fender
-the other branch travels through the fire wall to the interior of your car.
**i cant remember exactly if the branch feeding the interior lands on a vac / mechanical device behind the glove box or behind the manual hvac controls but you should see a single black in either place which will require you to take some things apart to find it.

-once you locate all the ends of each branch, you should disconnect each end and plug off one end and put suction on the other in order to verify a break or crack.

-the EGR gets source vac from a solenoid behind the coolant fill tank and that whole assembly is sourced from the "RED" vac line distribution fitting on the intake.

you do not always have vac applied to the EGR,, only at certain engine running instances.... so keep that in mind that at idle, and warm, the egr may not be in the game..

*the only way the EGR gets vac is when an electrical signal is applied from the computer up to the egr solenoid,,which then pulls on a rod that opens up the "RED" vac line path out to the designated "GREEN" egr vac line.


Once upon a time i found on my old 3.8 that the solenoid bank behind the coolant fill tank had a leak.  i could hear hissing.
if you follow the "red" engine source line downstream to the solenoid bank,, you will see how the red feeds one side of all but one of the solenoids.  you can then start making sense out of the solenoids like the white,, green, tan and orange and what things are doing.

the plastic elbows that catch the vac lines can crack, and there is one short 2'' long jumper hose that in my case was the fault,,

hope my ramble helps.............

Vaspooge issues 87 T bird 3.8

Reply #2
Very good information I appreciate it a bunch!!
Thank you Scott!!

Vaspooge issues 87 T bird 3.8

Reply #3
I eliminated all the emissions stuff on my 5.0 (except the canister purge). Just have 3 lines from the manifold (FPR, vacuum tree, canister purge). With the EGR and Thermactor gone you eliminate a bunch of potential vacuum leaks. Vacuum tree just has a line to the brake booster, cruise control, and the HVAC system.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Vaspooge issues 87 T bird 3.8

Reply #4
Ok so I took to the advice and near the solenoid bank I found wiring issues.
Two solid (no tracer) black wires cut one of them showed 13.5 volts with engine running the other had no power. Where are these suppose to be.?
In the same area there are two wires black with white tracer that come together into a single blade style connector what is this supposed to plug into?
The idle speed control has the black with white tracer and I have no power to any of the wires that plug into the idle speed control I would like to fix these issues.
I still have a rough idle after replacing fuel tank and pump but it is a constant rough idle the rpms are not fluctuating.
I Can't tell you all enough how much I appreciate the help.

Vaspooge issues 87 T bird 3.8

Reply #5
Forgot to mention KOEO test revealed codes 13 and 31 this time using paper clip method.

Vaspooge issues 87 T bird 3.8

Reply #6
I am VICTORIOUS!! the rough idle is almost completely gone.
I did remove the smog pump and it's components the only vaspooge issue now is a little plunger that is pulled up by vaspooge. This aporatis is on the drivers side near the throttle shaft it goes into the intake manifold on an angle.
Can I just apply constant vaspooge to this thing.

Vaspooge issues 87 T bird 3.8

Reply #7
you dont want to apply vac to that thingy. forgot what it does ,, softtouch  knows.

its in your haynes manual though,,, a round thing bolted to the intake drivers side sorta behind the ISC motor.  its an emissions port i believe.

Vaspooge issues 87 T bird 3.8

Reply #8
My  Helms manual is packed, but I believe that plunger is a pre-heater device. Don't leave it 'always on'. The solenoid for it is under your coolant reservoir. I'd leave it enabled.

Vaspooge issues 87 T bird 3.8

Reply #9
Quote from: walkingbird;466034
the only vaspooge issue now is a little plunger that is pulled up by vaspooge. This aporatis is on the drivers side near the throttle shaft it goes into the intake manifold on an angle.
Can I just apply constant vaspooge to this thing.
I think you mentioned that you were old. Maybe you remember when cars had a helical spring gadget on the exhaust manifold that operated a heat control valve. This allow the exhaust gas to heat the carb fuel air mixture to help with vaporization when it was cold.

Your CFI is like a single barrel carb, so it also needs this feature.
Your heat control valve is operated by vacuum. The vacuum is turned on and off by a solenoid operated vacuum valve. The solenoid is controlled by the EEC.

Vaspooge issues 87 T bird 3.8

Reply #10
Looks Like the OLD Iron Duke engine in the photo and yes Softtouck I remember the Vane and spring the prinl was a lot like the electric choke.
Thanks for your knowledge

Vaspooge issues 87 T bird 3.8

Reply #11
As softtouch  stated it is a method of using the warmer internal engine gases to atomise fuel during cold starts.
Thanks again jcassity

Vaspooge issues 87 T bird 3.8

Reply #12
LOL,, he's a one man gang on info.  he can look at a punch card and tell you what it says., proved it here a few years ago!

Vaspooge issues 87 T bird 3.8

Reply #13
I hope you found a 5.0L CFI in the jy,, just swap over your 3.8L injectors and that will let more air into the engine.  its a decent mod that the 3.8L will highly appreciate and its an easy mod you can instantly feel.  you will find that the 5.0L cfi air ports will match up perfectly to the EGR base plate and the intake. 
it seems the 3.8L CFI is intentionally bottle necked to restrict air flow. 

omitt the screens in the injectors,,, then where the fuel supply line is attached, remove the line and insert a tubular screen filter inside the CFI supply port like what is available on carb controlled tractors. 

also if your FPR is stock,, the top freeze plug can be removed to reveal an allen head,, which means you have a sock adjustable fuel pressure regulator.

the 3.8 is not a power house,, has a bad rap sheet mostly because its looked down on for being only a six hole.

I put over 300k on my white coug,, never had many issues and always got decent gas mileage. 

the thing i like about it is that it was tightly engineered, meaning that when something is going wrong, the car will act up and force you to fix it.

On the 5.0L,, i can let some small things go for  a while and fix them later but on the 3.8L, when they act up, there is no wiggle room and you have to fix it or it all goes down hill from there.

example,,
one the 5.0, the engine can tolerate the dizzy being off one tooth and you can bring it back in and the car will somewhat run ok,,,,

on the 3.8L,, it will not tolerate being off a single tooth,,  nope wont run right at all no matter what you do.

Vaspooge issues 87 T bird 3.8

Reply #14
Since I removed the smog pump and related nonsence the
The heat control valve never pulls off.
How did I loose vaspooge to it when I plugged the pink and black vaspooge lines off and directly hooked the green to the egg?
Something is amiss with the selonoids I am just not good enough with electronics to figure it out.