Exhaust

[koldcustoms]

'87 Supercab 4x4, 2.9L. Motor is original to the chassis except for the heads, (Ford improved design- OEM replacements).

Two questions:

1) The EGR valve has a short tube (vent?) protruding from its' body, above where the exhaust gas pipe taps in. Is it supposed to be capped, or should it be plumbed into the vacuum system? Should it be left open? It doesn't appear on the vacuum schematic.

2) The OEM exhaust looks as if it has two catalectic converters; one after the other. Is this the case, or am I looking at a Y-pipe with a heat shield and then the cat?

Thanks

 

[piotrsko]

EGR?? both of mine (85 2.8 and 88 2.9 CAL smog) are fuel injected and have no need for EGR plumbing, so I dunno what is that for so I can't help there. EGR was generally used on carbureted vehicles

The 88 has a double cat the 85 is dual exhaust. Both headers go into a "Y" style front cat with a "figure 8" 2 pipe front flange. I have seen single unit cats, but I think they might be aftermarket or 89 and better.

 

[Psychopete]

1) The EGR valve has a short tube (vent?) protruding from its' body, above where the exhaust gas pipe taps in. Is it supposed to be capped, or should it be plumbed into the vacuum system? Should it be left open? It doesn't appear on the vacuum schematic.

2) The OEM exhaust looks as if it has two catalectic converters; one after the other. Is this the case, or am I looking at a Y-pipe with a heat shield and then the cat?

Thanks

1) If I understand correctly (I never really messed with an 86-87 Ranger, but I am fairly sure this is how it works. Please correct me if I am wrong.), that line should be from the EVR valve. The EVR is a solenoid that opens when the computer tells it to. Otherwise it's open to the atmosphere. The other side of the EVR goes to the air box (a vacuum source). The trick to it is that it's hooked to the air box, if it were hooked up PAST the throttle body into the upper intake, that would essentially create a vacuum leak since the EVR is open to the atmosphere when it's off. What the EVR controls is vacuum to that nipple on the EGR valve, and that is how the EGR valve opens and closes.

2) 2 cats is correct.

Pete

 

[RustedRanger]

My 87 has an EGR,from what Ive read here most do up till 88 when they had a block off plate where the EGR goes from the factory and also a different computer.

 

[Wicked_Sludge]

EGR has nothing to do with being carbed or fuel injected. EGR systems are still used on most (if not all) 2009 vehicles. as rustedranger said, certain year 2.9's didnt have EGR from the factory.

 

[koldcustoms]

Regarding the EGR- I'll get back to you in a few days with a pic. I want to be sure we're talking about the same thing.

 

[koldcustoms]

Here's a link of the EGR valve for an '86-'87 2.9L. I couldn't get my camera to take pics, but this will work. http://images.remartautoparts.com/BWD/egr1186-BWD.jpg

As you can see, there are two small holes on the body of the valve- one smaller then the other. The larger hole is the outlet to the tube I'm referring to. The smaller hole is taped to secure the flange attached to the tube.

The vacuum actuator is connected to the EVR via a hose, on my truck. The outlet (larger hole), is it supposed to vent to to the atmosphere?

 

[Hawkeye58]

Okay let's see if I can shed some light here.
1) The small orifice is for a vacuum source.
2) The valve has a hole in the flange that mates to the intake to pass the fumes to the intake.
3) The large hole connects to the pipe that comes from your drivers side exhaust manifold which is the source of the fumes to be recycled per smog regulations.

Hope this helps you out.

Hawkeye