View Full Version : EFE system wierdness on an 88 Brougham/307

12-27-06, 06:55 PM
The previous owners really did a screwball job on the entire emissions system. It's come time for me to get it tested (still have a month and cash plus a buddy to transfer the title if necissary) and I want to get the emissions system working. She's got a new engine in her with 47k miles in her and a brand spanking new exhaust system including cat, they still have a shine on em' and no rust; the previous owners did at least that much for me. They sold it because it was getting around 7-8MPG (LOL!), which through a few part replacements is now upto 12-13MPG (water pump, power steering pump, oil change, trans fluid change, new radiator, distrocap replaced). I began replacing lines with high quality silicone ones and the car began to immediatly run better; the main issue I'v got now is WTF were these people on when they hooked the system up originally.

This car has 5 different vacuum systems and each has had a problem:

1: EGR. Carb-to-sol asm-to-EGR Lines crossed with the ILC being hooked in instead of the carb. That's been fixed, the EGR valve diaphram is now recieving pressure, and she accelerates and runs a lot less rough

2: ILC/Anti Dieseling circut. FUBAR'd by rats chewing through lines. Fixed and functioning properly as far as I can tell.

3: Cruise control circut. Diaphram wasn't hooked up, lines crossed between the CCV and it. This is not pictured on the image (if anyone wants me to draw them a diagram and upload it for future refernce for someone else, just ask). After fixing, it accelerates without hesitation and decelerated roughly as if sudden load was being put on, until I fixed the EGR/ILC reversed lines.

4: Thermactor/engine heat management circut had chewed lines. Not to mention I had an edelbrock performance intake on there for awhile and traded it for the stock (which was hard to find) which needed to be hooked up. This is working fine.

5: EFE (early fuel evaporation system). Now here's the kicker.

http://img387.imageshack.us/img387/1020/307vacuumlinesrg1.th.jpg (http://img387.imageshack.us/my.php?image=307vacuumlinesrg1.jpg)

What they've done is run the line that's supposed to be for the EFE into some lead hooking into the left head cover; it's a big thick line. The EAS and EAC seem to be completly missing from the circut and I am unaware of their location. They then ran a bleed off of the man vac line, between the Air canister and the anti dieseling solenoid, as a pressure source to the junction between the EFE TVS and the solenoid assembly. What's worse, they have two lines coming off of the carb junctioned into that. Here's a diagram of how it's wired currently (Note, not everything is pictured; but everything else is wired as the previous diagram on the radiator top shows and tests fine).

http://img176.imageshack.us/img176/8718/scanae8.th.jpg (http://img176.imageshack.us/my.php?image=scanae8.jpg)

I'm thinking of unhooking the carb line out of the EFE circut and running it directly into the solenoid to remove that problem. That still leaves me with a man vac tank bleed into the EFE vac system lines, which I have NO clue how to work with.

I also have 2 big thick connectors for vacuum lines coming out of the engine, on the righthand side behind the AC pump, between the AC pump and the carb; the connectors are attached to a tube which goes into the engine. I have no clue as to what this connector is but I'm thinking it's a part of the EFE system. Neither the EAS or EAC (Electronic Air Sensor, Electronic Air Control) are hooked up and I'm thinking the head cover lead and the tube lead are it. If the tube is hallow, it makes good sense that those are it.

The EFE TVS is hooked up properly; I had no idea where it was until I found it and unhooking it/hooking it up when the engine is cold appears to do nothing (not a big suprise). There is pressure back there, since I can hear it leaking if I unplug it.

Anyone have a clue as to how the lines should be ran or pictures of how theirs is ran I could take a quick gander at?

12-28-06, 10:09 AM
I went through this with my 307 about 6 months ago. Same problem - idiot previous owner had totally hosed up the hoses (pun only slightly intended) during an engine replacement. As you note, the hose routing decal on the car is not completely clear, and the factory service manual also has gaps, however with the two documents together you can figure it out.

First, the items on the passenger side of the engine behind the A/C compressor are the diverter valves for the air injection system. Is the A.I.R. pump in place on the engine below the A/C compressor? If not, that would explain why the hoses are disconnected. There are two valves in series in the A.I.R. system. The one closest to the A.I.R. pump is the dump valve that switches air to the air cleaner housing to prevent backfires under rapid throttle closing. The second valve is the diverter valve and switches the A.I.R. output between the injector pipes on the cylinder heads and the converter air tube. The cylinder head injector pipes are fed when the O2 sensor is cold. Once the computer goes to closed loop mode the diverter valve is supposed to switch the A.I.R. output to the converter to prevent it from overheating. Note that a failure in this valve can cause fresh air to be blown at the O2 sensor, causing it to think the engine is running lean and thus forcing the mixture solenoid full rich. This was the problem with my car.

I'm not sure exactly what your question is, however. Hook up the hoses as shown on the decal. The EAS,EAC, and EFE feeds all connect together to the vac tap on the carb as shown. On your hand sketch this is the tap below the letter "C" in carb that you've scratched out. The two 3-way connections at the solenoid box should not be there. Eliminate them and simply connect the two original hoses to the two middle ports on the solenoid box as shown on the decal. The 3-way tap between the vac tank and the anti-diesel solenoid also should not be there, so eliminate it.

Finally, I'm not sure what "head cover" refers to on the left side of your sketch. That line should go to the MAP sensor (manifold absolute pressure). On my car (an 86) that sensor is mounted on the pass side inner fender, but it could be mounted on the valve cover on your 88. It is a plastic box about 3" long, 1.5" wide, and 3/4" thick with a vac hose coming into the bottom and an electrical connector.

Good luck.

12-28-06, 03:25 PM
Oops, I forgot to mention the AIR and PCV (positive crankcase ventilation) systems. :X

Fallowing a hayens manual, the large vacuum hose coming off of the air compressor that goes to the air cleaner is putting out pressure, and the oil breather is moving air. So the PCV works. The Air system I am fairly sure is functioning properly; the air diverter/control valve is in place as well as the air pump, and the metal lines running into the engine exhaust manifold (I believe that's where they run) are not rusted through yet. I did disconnect some lines, one at a time, to put ring clamps on them, the kind with the screw, to make sure they were down all the way. I also checked for dryrot, nothing came up. You have given a really good description of the AIr system and I'll probably go out today with it printed out and trace the lines as you said.

Map sensor doesn't hook upto it; that is already hooked up and working properly. :) Everything but what I'v drawn is hooked up as the original diagram states it should be.

I'v got access to a digital camera so I guess I might as well use it and take some pictures to show you. *Edit: And here they are...*

The mysterious headers, hooked into the engine block directly between the AC Compressor and the Carbuerator. Nothing is hooked into them.
http://img179.imageshack.us/img179/5109/mysteriousheadersd1.th.jpg (http://img179.imageshack.us/my.php?image=mysteriousheadersd1.jpg)

Here's where the line coming off the carb that's supposed to be hooked into the EFE valve is actually hooked into. It goes right ijnto the head cover.
http://img179.imageshack.us/img179/4132/plugonheadcovervn7.th.jpg (http://img179.imageshack.us/my.php?image=plugonheadcovervn7.jpg)

In the meanwhile, can you dig up some pics of what the EAS and EAC should look like or point me in the direction as to where they should be? I can't find pictures of them anywhere and if I need to go out and buy them, I'll need to know what I'm looking for.

I also should note I have a buddy who had a 307 in an 86 oldsmobile cutlass supreme, same engine as mine, but the solenoid assembly he pulled off, which is similar to mine, has the two 3-way connectors in the same configuration. I don't think he did it considering he replaced the engine and with it the solenoid assembly and the previous owner wasn't mechanically enclined. I think it's some kind of wierd way to do it that mechanics use that works but not really.

Thanks man :).

12-29-06, 02:02 PM
Thanks for this thread I need it for my 84 Electra. My EFE is not connected to anything and I think a few of my lines are cross up too. And my emission routing has faded to a white piece of paper.

12-30-06, 07:25 PM
I did some looking around and figuring around with the carb and I'v figured out the reason the EFE valve isn't kicking in, what my mysterious header is, and a few other things. *begins thinking outload for everyone's benefit*

The carb produces vacuum, and lots of it. The quadrajet actually produces vacuum out the various metallic lines coming out of it through the use of the manifold vacuum which is caused by the movement of the cuylanders drawing in air. The guys who developed the quadrajet put 4 barrels in because it produces more air flow but also becuase it allows for finer adjustment of the vacuum system; if you cast metal causways connecting the barrel and a line on the outside of the carb, it produces negative pressure (sucks air into the carbuerator). When a barrel is closed, it produces LOTS of negative pressure; meaning air is being sucked into the carb from the system. As the barrel opens to allow air to move in freely, this pressure gradually dissapears. As acceleration increases, again, this negative pressure increases. Literally, all the vacuum lines tied into the carbuerator are either normally producing negative pressure or produce negative pressure during certain stimulation (such as wide-open throttle).
Additionally, quadrajets have 4 barrels; 2 small and 2 big. Which means they have better control over what pressure goes where depending on how fast the engine is sucking air and which barrel is open.

The vacuum tank gets it's pressure from the air control valve, which is controlled by a solenoid hooked into the ECM and supplied with positive pressure by the manifold vaccume, AKA, air pump. That solenoid doesn't kick in while the engine is warming up. Meaning, it doesn't pressurize until the ECM tells it to. In my diagram, the WTF tie-ins are producing no positive pressurization (that is to say, no air is moving into the lines) while the engine is warming up because the solenoid is closed.

The Anti-dieseling solenoid hooks into the ILC; the line on the ILC seems to be a negative pressure diaphram with 2 sides to it. I believe one side moves the screw out with positive pressure and in with negative pressure and the other moves the screw out with negative pressure and in with positive pressure. In my car, this is the ladder; negative pressure moves the screw out and positive moves the screw in.

When the engine turns on, the rear center lead coming out of the carb produces a lot of vacuum because the 2 large barrels can't move due to a doo-hickey on the passanger side of the carb. This doohickey moves back in 3 seperate stages depending on the pressurization of the two diaphrams on the passangerside of the car and eventually kicks a lever which catches a metal bar which keeps the 2 big barrels from opening even if you were to press down on the petal. Only when both valves have been sufficiently pressurized will kick go off and the 4 barrels open freely. Alternativally, the kick is hooked onto another doohickey which hooks into a metal line that goes into the engine; I believe this also moves the kick depending on what the engine needs. Because the 2 larger barrels can't open up, and that lead hooks into them, the 2 leads at the center back of the engine get a lot of negative pressure; air gets sucked out of them and into the engine.

Normally this lead hooks into the anti-dieseling solenoid which sucks the screw foward causing high idle and later, once the engine has warmed up the pressure is slightly released by the opening of the 4 barrels causing the the ILC screw to move the throttle back to a less intensive point. When the throttle is being controlled manually via the petal, this vacuum is replaced with a further negativally pressurized which the VDV and VRV valves both delay some the excess pressure (with the potential of the solenoid, which is normally opened, closing up due to the ECM saying "hey, I'm accelerating, lets not allow that ILC screw get high that when he takes his foot of the petal the engine will stall"). When the car is being turned off the anti-dieseling solenoid energizes, allowing a LOT of pressure to be released into the ILC from the vacuum tank, causing the screw to go down and 4 barrels of the carb close up completly, choking the engine off. If the ILC throttle stays too far up, the engine will continue to run-on.

With my system, there's a tie in between the EFE lines, the vacuum tank and the rear center carbuerator lead. During engine warmup, the entire system of lines has negative pressure which causes the EFE valve to open and the ILC screw to move outward to it's maximum causing high idle; this is normal car heating up operation. Additionally, the immediate negative pressure generated by the engine is soaked up in the vacuum tank. When the engine warms up, the air control valve solenoid opens causing the pressure to reverse from negative to positive within the vacuum tank and entire system. The EFE valve, if it's been shut by the negative pressure, opens since no pressure is going into it now since the Thermal Vacuum Switch (TVS) has since closed. The lines consisting of the ILC, VDV, VRV, anti-dieseling solenoid and so on get no pressure whatsoever at all when during normal operation they should be getting negative pressure, so whatever the car was at when the system depressurized it stays at. As the car is driven or idles, the ILC screw is slowly pushed down by the throttle spring and after being driven for awhile, will stall if the throttle isn't manually held open, which subsequently, won't happen unless the engine cools down. :X

So how the heck do I fix this? What's the correct way to do it? The diagram is dead wrong; the EAS and EAC don't actually exist I believe. I'v searched everywhere I could, including on other 307's, without finding one.

Bascially, the mysterious header on the engine is a thermally activated switch which is normally closed and hooks into the engine coolant; it opens when the engine is hot. During engine warm-up, this is normally hooked into PCV intake on the passanger side of the engine on the valve cover.. The valve itself only allows air to move out of the valve cover and is NORMALLY hooked upto the carbuerator at the base to recirculate gas buildup in the crankcase.

However, on my carbuerator there's a problem with that. You see, the lead that's normally supposed to be there to provide extra pressure is missing or mislabeled; I have a replacement carb by the date on it which has all the leads on it it normally should have. Either that or it is listed, however, the diagram is wrong. You see, when the car turns on the EFE valve NEEDS pressure and lots of it, which are generated by the 2 front barrels of the carb being slightly opened during high idle. This thermal switch is closed; preventing the suction from being used to circulate gasses; if a 3 way were installed between it and the EFE, the EFE would never open since there'd be little to no pressure. So the mysterious header kicks the PCV system into operation when the engine is warm as a way to share that one vacuum header coming off of the carb with both the EFE and PCV system. Additionally, the PCV should be OFF when the engine is first warming up as it will circulate warm air away from the engine block and into the exhaust; allowing the oil to warm up is a good thing when the engine is first starting up. Sure, there'll be blowby gasses but those will be circulated out by A: the PCV system function during a warm engine and B: heat causing the lighter materials that have found their way into the engine to combine with fresh air.

The EAS and EAC are nowhere to be found; I can't even find a website that describes what an electronic air controller or electronic air sensor are. My guess is that they referr to parts of the PCV system in a ultimatilly FUBAR fashon since the EAS comes before the EAC and may very well keep the EAC from getting air.

Tomarrow I'm probably going to go out and hook it up right. :) FUNKY is all I'v got to say. I wish they'd hook this stuff up right at shops.

12-31-06, 06:40 PM
Update: I just hooked the system in as it should be and idled it to running. It was dark out and I couldn't see if the EFE valve was functioning or not. Anyway, it runs great and is working exactly as described! I'v never seen this car run so perfectly before. I still have yet to take it for a test drive, and I still have some work to go yet, but if tonight works I'll make a modified set of diagrams for you guys so you can see what I'm talking about since there's no place anywhere on this forum for where a complete set of vacuum line diagrams for the 85-88 cadillac brougham can be found.

Also, the mysterious part seems to be a dealer-only part. Funky, eh?

01-02-07, 03:56 PM
Here how it is on my 84 307.
The other one is running the charcoal cannister. on the front pass. side.

I need to find a vacuum guide to my 84. About 70% of your lines are on par. with my engine from what i can tell from my sticker.

01-03-07, 03:40 AM
Here is a link to a page with the most popular vacuum diagrams.



01-03-07, 12:26 PM
That's certainly wierd. My CCV has 4 lines on it and it's hooked into the purge solenoid and canister directly. With your setup, that lead is acting as a normally-closed thermally actuated pressure valve. When the engine is cold, it stops all airflow between the two connectors; as it warms up, it opens up. *thinks outloud for a moment*

As the tank warms up, fuel expands and generates vapors which, if left unchecked, would warp the gas tank. Since you don't want gas escaping into the atmosphere, you need a way to purge these gasses. Basically, the gas tank has a metal hose running to the charcoal canister from top of the gas tank; as gas expands it flows to this canister where it is stored. Under certain criteria, the ECM energizes the purge solenoid, allowing the carb to suck gasses from the canister.


That article says the items called a TVV; Thermal Vacuum Valve. The article says that on mechanical systems it's used to operate the EVAP system without an ECM. However, my car has a C3 computer system, and a purge solenoid which means it isn't mechanically operated. Your car may be mechanically operated but somehow I don't believe so.

I'm using the valve as a way to share one vacuum connector between the EFE and PCV systems. AFAIK, the PCV system doesn't need to be operating until the engine gets upto temperature since chamber pressure is going to be lower. More importantly, my carb is a "model 8", which means it's a generic replacement carbuerator and not specific to any manufacturer; it happens to be missing a connector.

Anyway, after fixing the spark plug wires and taking her out for a drive last night, I'v got to say I'v never enjoyed driving that car that much; she didn't rattle, stall, miss or anything and it's got some hefty pep :). It's making a rattling noise, however, which means I need to find it and squash it. I'm thinking fuel filter but I am unsure; it is causing the engine to lag some. I also did an oil change; pulled about 3 quarts and added in 6; it's full now but I have no clue as to where 4+ quarts went since last time I put in 8. No oil in the radiator, nor fluid in the oil, but it looks like I'm in for a headgasket replacement this summer. :X

01-03-07, 04:10 PM
About 70% make since to me.:( All i know is my cruse control was mixed up with the line off the the air control box on the back driver side of the motor.

My thermac is working well now, the EFE system is hooked but does not work. Got to hit is with some more oil. But I still have one line I don't know where it goes. But now on a cold take off it just goes. It does not feel like it well stall if i push it.

Also what the heak is this?

01-03-07, 06:19 PM
Here's a tip. Throw away the Haynes/Chilton manuals because they are crap. Spend $20 on ebay and get a correct factory service manual for your car. Everything you ever wanted to know and more is completely spelled out for you.

01-06-07, 04:09 AM
I know the chiton and hayens manuals are crap, but it's what I'v got to go off of right now; this forced me to research and get a very good idea of what I'm doing. When I get the cash though, hell yes, factory manual all the way.

That part is the VDV or VRV. Vacuum delay valve or Vacuum Relay valve I believe. Pretty sure it's the VDV as the VRV has a metal top. It goes inbetween the anti-dieseling solenoid and the VDV/VRV and the solenoid assembly.

I have yet to touch my EFE valve which I am sure isn't functioning, however make sure the EFE vacuum diaphram, the thing which moves the lever, is working. I'v found the best way to work through rusted parts is not to use oil but lithium grease and brake cleaner. Oil has a tendancy to oxidize, dry out, and combine with what it's coming into contact with. Lithium grease works it's way into whatever you put it on and helps to allocate friction where it's needed to break rust off and then helps to grind it into fine particles. Basically, it makes the overall friction less and makes turning things easier, but when those things are turned it grinds the rust against itself causing it to break away in large chunks and as the bolt is turned, those chunks get smaller. Brake cleaner dissolves the lithium grease and washes out the particulates to an extent, makes rust softer. I'v used that process to re-tap severely corroded and rusted bolts before.

You're going to want to lube that part with lithium grease anyway; lithium grease can handle high-temperature applications like that without getting badly screwed up.

01-07-07, 01:20 AM
Thanks to you Gwokable and oldspower.com it's the differential vacuum delay valve. It runs from the vacuum box to the VRV then VDV.

01-10-07, 04:37 AM
Hey Rocketfast, do you have a can purge solenoid?

It's located on the passangers side of the carb and should look something like This (http://www.napaonline.com//MasterPages/NOLMaster.aspx?PageId=470&LineCode=CRB&PartNumber=228211&Description=Canister+Purge+Solenoid)

01-11-07, 03:23 PM
nope. They really did change a lot on the 307 in 4 years