Need help with manifold vacuum line tree (octopus)

qlmabry · 06-07-2003, 04:15 PM

I have a '94 XLT and am having problems with it running rough. It starts up okay but after a few minutes the CEL comes on (I'm still trying to find my code reader to find out what the codes are... never let your kids play with your tools). A few minutes after that, the engine shudders and then either almost dies or completely dies.

I think I have a vacuum problem and am trying to track it down. After searching the forum and reading over previous posts (lots of really good info out there) I think I have it narrowed down to a few possibilities (possibly a few different problems too).

Now for a stupid question... are all the connection points on the vacuum tree on the rear of the manifold supposed to have either a line or a cap on them?

One of the connection points has nothing on it but I can't find anything in either the Haynes or Chilton manual to suggest if it should have a line or be capped (I don't remember it not having something on it, but I can't find a loose hose anywhere). All of the other connections appear to run to where they should according to the manuals (Break booster, FPR, VCV, tranny, speed control, EVR). If I put my finger over the connector, the idle seems to smooth out. When I take my finger off the engine sputters and wants to die. This would suggest to me that something should go there.

Anyone have any ideas??

Q.

*SteveVB* · 06-07-2003, 04:29 PM

Quote:

Originally posted by qlmabry
Now for a stupid question... are all the connection points on the vacuum tree on the rear of the manifold supposed to have either a line or a cap on them?

Q.

YES it should be capped or have a line. Most likely a cap, the rubber gets old and the caps loosen and blow off during a back fire or some other event. Had any backfires lately. Also check all of the hoses leading to the tee for trans fluid and or swelling- this seems to cause the same thing.

I would get a new cap and a clamp for it.

Good Luck.

qlmabry · 06-07-2003, 04:57 PM

There is some fluid that appears to be leaking around the tree (actually, it's pretty much all over all of the hose ends on the tree) I'm not sure which line it's coming from though. I know its not the EVR, break booster, or the speed control. I don't think it's coming from the tranny either. I'll have to look at them all to make sure.

Any suggestions for where I can get replacements for the hose boots on the smaller hoses? I've noticed a few of those are very loose.

Glacier991 · 06-08-2003, 11:44 AM

I'd guess you are sucking transmission fluid from a bad modulator. You can get caps in assortment packs or multiples in certain sizes at most general purporse auto stores (autozone, Pep Boys etc) I do not recommend you clamp it on because a backfire will just ruin something else, the "pop off" effect may serve as an unintended safety valve. But with a cap off, the vacuum leak is so great it will not run hardly at all, and WILL NOT idle, period. HTH.

Happy exploring

Chris

silver stripe · 06-14-2003, 04:53 PM

i had the same issue as you are talking about on my x also // the first time it came off was the far back one and i lost the hose, and after digging with my hand behind the head, from the driver side, i felt it was in a little cap, behind the head, and i resolved mine with a few tie straps after getting fed up with the things popping off // its been that way now for almost 3 years, no problems

06-07-2003, 04:15 PM	#1
qlmabry Wannabe Elite Explorer Colorado Springs, Colorado 1994 XLT Join Date: Mar 2003 Posts: 2 Vehicle Specs (Original Poster)	Need help with manifold vacuum line tree (octopus) I have a '94 XLT and am having problems with it running rough. It starts up okay but after a few minutes the CEL comes on (I'm still trying to find my code reader to find out what the codes are... never let your kids play with your tools). A few minutes after that, the engine shudders and then either almost dies or completely dies. I think I have a vacuum problem and am trying to track it down. After searching the forum and reading over previous posts (lots of really good info out there) I think I have it narrowed down to a few possibilities (possibly a few different problems too). Now for a stupid question... are all the connection points on the vacuum tree on the rear of the manifold supposed to have either a line or a cap on them? One of the connection points has nothing on it but I can't find anything in either the Haynes or Chilton manual to suggest if it should have a line or be capped (I don't remember it not having something on it, but I can't find a loose hose anywhere). All of the other connections appear to run to where they should according to the manuals (Break booster, FPR, VCV, tranny, speed control, EVR). If I put my finger over the connector, the idle seems to smooth out. When I take my finger off the engine sputters and wants to die. This would suggest to me that something should go there. Anyone have any ideas?? Q.

06-07-2003, 04:57 PM	#3
qlmabry Wannabe Elite Explorer Colorado Springs, Colorado 1994 XLT Join Date: Mar 2003 Posts: 2 Vehicle Specs (Original Poster)	There is some fluid that appears to be leaking around the tree (actually, it's pretty much all over all of the hose ends on the tree) I'm not sure which line it's coming from though. I know its not the EVR, break booster, or the speed control. I don't think it's coming from the tranny either. I'll have to look at them all to make sure. Any suggestions for where I can get replacements for the hose boots on the smaller hoses? I've noticed a few of those are very loose.

06-08-2003, 11:44 AM	#4
Glacier991 EF Tranny Guru Sacramento, CA 95827 1992 XLT Join Date: Feb 2003 Posts: 9,830 Vehicle Specs	I'd guess you are sucking transmission fluid from a bad modulator. You can get caps in assortment packs or multiples in certain sizes at most general purporse auto stores (autozone, Pep Boys etc) I do not recommend you clamp it on because a backfire will just ruin something else, the "pop off" effect may serve as an unintended safety valve. But with a cap off, the vacuum leak is so great it will not run hardly at all, and WILL NOT idle, period. HTH. Happy exploring Chris

06-14-2003, 04:53 PM	#5
silver stripe Wannabe Elite Explorer Ontario 1992 explorer eddie bower Join Date: Jun 2003 Posts: 56 Vehicle Specs	i had the same issue as you are talking about on my x also // the first time it came off was the far back one and i lost the hose, and after digging with my hand behind the head, from the driver side, i felt it was in a little cap, behind the head, and i resolved mine with a few tie straps after getting fed up with the things popping off // its been that way now for almost 3 years, no problems