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Help with car running bad

2K views 15 replies 5 participants last post by  sven914 
#1 ·
Okay, I gave my car a tune up and the funny thing is it runs hella worst now then it did before the tune up. I think it is either the vaccum lines or the custom spark plug wires I put together. First off on the 1990 Caddilac Brougham 307 oldsmobile engine is there two vaccum lines that arent connected or do all vaccum lines suppose to be connected? If those two lines arent connected to anything it is definitely the spark plug wires. The vaccum diagrams I find for this car are so gd unreadible I cant make out half the things on there but these two vaccum lines I cannot find anything that goes to them. I gladly appreciate the help.

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http://carphotos.cardomain.com/ride_images/3/3489/1/33720000075_large.jpg Okay on this damn diagram you see the two lines on the very bottom that one hose says from manifold? What the hell is that circle? The circle on the bottom left corner? If somebody could give me a link to a picture of what that represents that may be where the two hoses connect to.
 
#2 ·
Might be the timing/wire routing but probably the custom wires. Buy a spark plug tester and put it inline with the wires. Its a cheap tool and will tell you exactly which wire is not sparking. Plug any hoses with screws or something and run it again. I did custom wires and it was a detailed job so, if you arent 150% you got them right, I'd start their.

Sven, is that your diagram?
 
#3 · (Edited)
http://carphotos.cardomain.com/ride_images/3/3489/1/33720000075_large.jpg Okay on this damn diagram you see the two lines on the very bottom that one hose says from manifold? What the hell is that circle? The circle on the bottom left corner? If somebody could give me a link to a picture of what that represents that may be where the two hoses connect to.
On the passenger side of the engine compartment, mounted to the fender, there should be large foot-ball shaped vacuum canister with two vacuum ports.

The one hose connects to a vacuum port located on the front of the intake manifold. I don't remember exactly where the manifold port is, but think it is located on the driver's side, at the very front of the intake manifold.

The other hose connects to the Knock Solenoid, which should be located on the driver's side valve cover, and has a red electrical clip. The knock sensor has two ports; one that goes to the Idle Load Compensator (near the carburettor) and the other goes into a round SNS object.

Here are some picture I've taken of my vacuum routing:






As a side note: You may notice my hoses are color coded. I spent 4 years fighting vacuum leaking and a very messed up hose routing, where almost nothing was plugged in where it belonged, and a lot of things were disconnected. Eventually I got tired of it, replaced all of the hoses, and routed them all back to their factory locations. While replacing them, I marketed each one with a unique combination of three colors, so now I know exactly where each and everyone of them is supposed to be.
 
#6 ·
Hey man I made a video I am sorry for sounding frustrated but the car turned off on me on the road. seven914 the vaccum hoses are the ones coming from the intake manifold and the knock solenoid. I think we have different engines because the football looking vaccum canister on the fender does not have two ports for those hoses
to connect to. Here is a link to the video https://www.youtube.com/watch?v=TUNjN5JG8AQ
 
#7 ·
You can take it from me, the vacuum lines on this engine are source of infinite frustration. It took me several days to re-route all of my vacuum lines and replace them, and it's still all a clusterf**k of snakes that makes absolutely no sense.

On that note, I was wrong about that football shaped vacuum canister; it only has one vacuum port. You need to splice into the hose to make it go to the knock solenoid and the manifold port.

If you look at the first picture, of the hoses I posted, the hose marked with the red line is the one coming from the vacuum canister. If you look closely, you can see I have three splices in that hose; the first goes to the manifold port, the second to the Cruise Control servo, and the third goes to the Knock Solenoid. The hose goes beyond the third splice, wraps around the back of the carburettor and then connects to vacuum port on the Brake Booster (this connection is not shown in either my vacuum diagram or the one provided in the GM service literature).

The vacuum diagram in my Service Manual shows that canister with two ports, so there may have been a special hose, which neither of our cars has any longer.
 
#8 ·
Pull a plug wire off the dizzy and start the car, it should run even worse. Now plug it back in and try another wire. When you pull a wire and the car doesnt run any worse, you have found the cylinder thats not sparking. The vacuum canister you are figuring out is an extra source of vacuum for when you turn on your accessories. The knock sensor is actually an anti-diesel solenoid used to make sure the car doesnt diesel when you turn it off. If you think the line is the issue, plug it with a screw to see if that makes it run better. Can you actually feel vacuum coming from the hose? Does it sound like its running on all cylinders when it does run or does it sound like its missing pretty bad? I just think you're going down the wrong road.
 
#9 ·
So the knock solenoid hose goes to the brake booster and where does the hose that comes from the intake manifold?

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Once I get the car vaccum lines connected and if the car still runs bad I am going straight to the spark wires.

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I want to know the stock set up. Where did those hoses come from originally? I took them off and for some reason I dont remember where they came from.

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Guys were going to have to figure something out fast this car will not get over 30 miles per hour. Its 99 percent likely not the spark wires now. I cant have a car like this
 
#11 ·
Guys I used some pcv Ts and got them all spliced in there was a lot more Ts than your picture showed. I somehow had more hoses two more hoses. The car seemed to run better but I took it on that test drive and the same shit happened at 25 to 30 miles per hour the car would not go past and when you added more fuel it would begin to turn off. At idle you can rev the car pretty high but for some reason driving down the street car runs good till thirty. I just want to know would this be a vaccum problem still? Car ran perfect before I decided to give it a damn tune up. So I still hint it was vaccum still.
 
#13 ·
Have you replace all of the hoses?

You can have everything routed 100% correct, with everything going to right places, but if the hoses are dry-rotted or have a small pin hole, the car is going to run like crap. If the hoses were old, and you had to move one or even just stretch it to get it out of your way, it can cause a serious vacuum leak.

Most parts stores sell hose by the foot, and when I replaced mine, I got 20ft of it for $5.00. All of the main hoses are the same size, so you don't need to worry about mixing and matching.
 
#14 ·
Fuel is another good place to look along with timing. Wires ran correctly or something being pinched by a valve cover. Almost sounds like the advance is not working correctly. Not sure how the dizzy advances with the CCCarbs but it would run good with no load and run bad under load if the advance werent working correctly. Cap on nice and tight?
 
#16 ·
The 307 has electronically advanced timing, based on calculations in the car's computer.

The distributor cap has two electrical connectors at the bottom of it. During a tune-up, it would be very easy to pull one of them loose, and cause the distributor to revert to base timing; without the advance timing, the engine would have trouble at driving speeds. So that is something to be checked into.
 
#15 ·
I don't know if they change from the 82 I had but with mine it would run great and as time passed and demand increased with speed particulates would build up on the tank sock until it barely ran or stalled out. It would sit for 20 minutes, the junk would fall off and back into the tank, and then the cycle would start over again.
 
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