Just replaced a starter in my 850T. Ended up having to replace a lot of vacuum lines and the injector seals.

Car starts right up but immediately revs up to a dangerous level, so I immediately shut it down.

All vacuum lines appear to be hooked up right per diagrams I have seen and the sticker.

Thanks for any help.

Howard,

Time to follow your brake booster vacuum line. From the booster, the line goes down to the left side, under the air cleaner, makes a sharp right between the air cleaner and battery, then crosses over to enter the manifold between the IAC pump and the vacuum tree.

It is right where you would hit it if you were replacing the starter. A smoke test would also leak up past the vacuum tree.

Klaus
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Always willing to listen, just not able to take direction.

would capping the fitting where the booster line mounts on the throttle body and running the car rule out that the booster hose as the bad agent? is that white thing a check valve (under air filter housing)?

thanks for your input. i do have access to a vacuum meter.

Cruise control has its own little vacuum pump located under the battery tray. The vacuum line goes from there to the brake pedal switch. CC has nothing to do with engine vacuum.

Time to re-check your vacuum line positions.

Klaus
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Always willing to listen, just not able to take direction.

That manifold fitting is in a tough spot, but capping it would make a difference if the line is porus.

I haven't looked under the air filter on my car, but the one way valve is supposed to look like that. The plastic is barbed, so the line does not want to come apart.

Klaus
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Always willing to listen, just not able to take direction.

i disconnect the switch by the brake pedal that has 2 wires and a hose going to it. it was the easier one of the two to get at.

car now runs fine. now i just gotta figure out what i did and why it works.

thanks for helping out.

That's the cruise control switch??????? Why is that operational?

Klaus

EDIT: CC is not supposed to work until you are going at least 30mph. Something really wierd in your wiring. Perhaps throttle position sw is messed up or some other wire is plugged in upside down.

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Always willing to listen, just not able to take direction.

You might want to look at http://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=18585 and especially the reference to the pdf. Comments there suggest it could be the vacuum line got misplaced at the pump?

on edit: this is the more appropriate pdf for your machine:
http://www.volvoclub.org.uk/tech/service/850/CruiseControlSystem.pdf

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'96 850T and '83 244 DL both at about 200K, '97 850T5; gone but not forgotten '81 245 and '64 Amazon

fitting capped. all symptons persist. car still idles properly when the brake is depressed.

does this imply that the brake's effect is electronic, or at least not vacuum related? my poodle brain tells me so.

the fact that the car has the ability to idle properly with the brake pedal depressed to me means that stomping the brake pedal (now without a vacuum consequence (or does it somehow still have one?)) does something to correct what is wrong here.

with the brake booster line removed and capped, does a propane/starting fluid/etc. become more efficient?

it drives me nuts that this thing idles right with the brake on. that, to me, seems like all vacuum issues are no longer (if they ever were).

As you replaced the starter without removing the intake manifold, it is a possibily that in the process the large vaccum hose coming from the oil separator came loose or broke. Check that one out. It won´t be visible so you will have to "feel" it with your hand and use a good flashlight in the process.

If it is broke or loose you have one giant vacuum leak causing the rpms to shoot up.

Good luck

Not sure how I would put that hose back on if it were off...

I can touch the plastic body and hoses but can't move much under there. With the battery and some hoses, etc. out of the way I can look under the manifold and see the big hose clamped to the top of that thing and it looks like a vacuum sized hose is tapped into big hose close to the clamp. (??) It all looks ok.

Follow it to the turbo inlet hose near the turbo. Looks ok there, too. Can't see it everywhere along the way, but it doesn't look beat up at all where I can see it.

Any idea why hitting the brakes when the engine races shuts(or slows) things down? Is it simply because this is vacuum related, or does it point to something more specific?

Thanks for helping me out.

as I said yesterday I think you're stuck until you get a smoke test.

You can do a DIY test if you've got a little air:
http://www.fiero.nl/forum/Forum1/HTML/081547.html

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1998 V70 AWD->FWD->AWD Turbo 215k+

wanted to let you know that i made a smoke tester with a cigarette and a classic diner style plastic ketchup bottle. found the leak within 2 minutes.

it was a bad o-ring under the vacuum tree. not visible without the smoke. should have been something i replaced with the vacuum lines, or sooner, but didn't know any better. i reckon i destroyed whatever type of seal i had there when removing hoses from the vacuum tree.

thanks for the tip. i had never heard of a smoke test before. haven't fired things back up yet, but this was a pretty big leak. very hopeful that it'll work now.

I like your tester!!

You are correct, I would have never guessed the tree O ring. And yes, there is enough air to freely rev your engine to red line.

Klaus
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Always willing to listen, just not able to take direction.

I like the tester too.

So I found the leak and put a bulk o-ring on the tree. Looked ok til I got home and tried to put things together. Not working.

It surprised me that the Lancaster PA Volvo dealer didn't stock that o-ring. Not that the locale hit the big time, but I just thought that would be a common consummable part. I really don't think it should be an o-ring, though. My independent Volvo people (who I really respect as a DIYer) typically stock these PM parts which the dealer does not often stock. I will be ordering the Volvo gasket/o-ring/whatever, but I still want to seal this thing and make sure this is my bad actor.

I am gonna do a single wrap of super 33 3M electrical tape to temporarily seal things to see if I'm barking up the right (vacuum-)tree.

Any suggestions on what belongs there? The old gasket was flush with the tree housing. It looked like it had a rectangular cross-section gasket(hose-washerish) as opposed to being an o-ring.

Thank you Klaus.

Number 9 is the o-ring for the vacuum tree Do you have any junkyards nearby? If so, you should be able to find one that you could put on and solve the problem today.

The electrical tape should make a good enough seal, the other option would be going to Lowes and getting a rubber gasket and just cutting it to fit. And lastly, if you've got a friend with an 850 with about half an hour to spare, you could convince them to let you switch trees for a moment to verify your problem is with the seal.
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If you're not driving it "like its stolen," are you really driving?

Pretty sure I got it sealed up good with the tape. No change in the idle.

The car will run fine indefinitely if I keep the my foot on the brake pedal. As soon as I release it, it ramps up to 5K+ RPM if I let it. My helper tells me the engine moves a bit more than I would expect it to. Is this possibly associated with a bad motor mount?

Look at the brake booster vac hose for leaks. When you have brake on it may be pulling the vac for braking until you release pedal, then the engine starts to suck the air from that hose.

I don't think they're related but the engine does move a bit when you shift/start the engine.

Do you have a propane torch? Leaving the flame OFF if you turn on the gas will any get sucked into the intake at the tree and around the engine bay.

Do you have a vacuum meter, or an Autozone nearby that you could use one at, and see how the vacuum looks a the tree? See what happens when you push the brakes.
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If you're not driving it "like its stolen," are you really driving?

maybe you read some of these posts, but the brief thing is such:

i capped the throttle body to eliminate the brake booster line.
same symptons all around; high idle brought under control by stepping on the brake.

it seems like i need to make a list of all the things that happen when i hit the brake, and then start ruling them out as related "cures".

btw, do you know what the wires are that attach to the throttle cable bushing on the firewall?

thanks for stickin with me on this.

Hi,


Thermoset is a large problem in the field of elastomerics. It can generally be solved by using increasingly vicious chemicals, combined with an increased durometer.

In other words, the o-ring lost its round shape because it’s old.


Goatman

Thanks for the tip. I didn't know what that was until yesterday. I am ready to start to find a way to get that done, but economics come into play. The car cannot be driven, so a tow will be necessary unless I find a way to have it done at my place.

Depending on what things cost, this car may be sitting for a while.

Would you also agree that this all seems vacuum related?

Thanks!

Long shot here, but it could be that the IAC gets stuck open when the car is hot. That wouldn't seem likely if the car normally idles properly, but just to be sure ...

The valve gets clogged up and stuck, but usually in the closed position. Could be that when you start the car it opens but can't close again. It probably needs cleaning anyway, and would be easier than the smoke test. Just take it off and run some carb cleaner through it. The valve should rotate freely when you have it off, or with the engine cold, just take off one of the large hoses and see if it wiggles easily with your finger. Pretty robust, no need to worry about damaging it with your finger!

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'96 850T and '83 244 DL both at about 200K, '97 850T5; gone but not forgotten '81 245 and '64 Amazon

I have taken off the IAC to clean it. The "bobber" moves freely (bobbles back and forth) inside there.

Symptons come up whether or not the IAC is plugged in or not. Also, so far this is only a cold-start situation, as the car has not been able to run for but a few seconds at a time.

This thing revs as if a brick was on the pedal. Not just a high idle.

Let me know if you have any other suggestions and thank you for helping.

You still have a large leak around the intake manifold. Make sure the injectors are inserted completely and sealed. Check the torque of the manifold bolts, any leakage there will produce the high idle.

The vacuum line by the PS pump is not cracked? No empty holes in the vacuum tree? The IAC hose to the top of the tree is secure?

Klaus
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Always willing to listen, just not able to take direction.

The injectors snugged into place and the rail is bolted into place also. everything seems snug and right. short of redoing things, i would say it is good. intake manifold was never removed. no bolts attaching it to the engine were touched. fpr hose is an old one which appears ok but is original i would guess, as is the one going under the spark plug cover. the others are new. no open holes or cracks on tee. iac is connected well and the larger fresh air hose leading in to the throttle body looks fine.

vacuum line by the ps pump. not sure what that is, unless you are referring to the fuel pressure regulator line. which is plastic with rubber and braided ends.

not sure what the brake booster line looks like where i can't see it.

this thing is revving HIGH. it would blow up if i didn't shut it off 2 seconds after it starts. it idles ok for about 1.5 seconds and then immediately ramps up dangerously.

thanks

First, pull off the large air hose to the throttle body and make sure the lip is nice and round. People have had trouble getting it on straight, allowing air to get in.

To check the seals for the injectors, take off the dirt shield so you can see the bottom of the injectors. Pour/spray water on the bottom of the injectors so that a small amount of water collects around each injector base. Start the engine and then shut it off when the rpms climb. See if the water is still around each injector, if not, there is a leak.

The vacuum line close to the PS pump or #1 cyl should be present on the turbo engine. Hard to see and prone to crack with age.

Klaus
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Always willing to listen, just not able to take direction.

I did not pull off the large hose during installation but I will when I get back to this thing this evening. Who knows what all got moved during this event.

I like the water injector treatment. Do I need to back out the blue rubber "debris shield" washers that are towards the bottom of the injectors?

Still at a loss on the power steering/#1 cylinder vacuum line. Can't imagine that it wasn't there before this operation, but getting moved around by now wouldn't surprise me. I'll check that out, too.

Thank you.

Negative, I just meant the aluminum shield in front of the injectors so that you can see the bottom of the injectors. Do not move the injectors, unless you find one that is obviously loose at the bottom.

I am still trying to figure out why you replaced the injector O rings.

Klaus
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Always willing to listen, just not able to take direction.

This whole process was a starter replacement. Vacuum lines were disturbed during this process. Most ended up getting replaced. The injectors get involved once I start replacing the wire loom surrounding the injector wires going past the vacuum tree. There was nothing wrong with the injectors, but as things go...

I believe, that at the time, I had no clue there was a dirt shield and that removing the bolts on the injector rail would result in injectors coming out.
I had a broken cap on one. I had the o-ring kits available, and they are now installed.

So, that's why injectors have become part of the puzzle.

Do you have an idea what the vacuum line I'm not seeing by the power steering pump is to be connecting?

On my 95T the vacuum line went from next to #1 runner at the intake, to just in front of the turbo - connecting to the PTC valve.

My suspect would be the injector seals...

Klaus
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Always willing to listen, just not able to take direction.

I now have seen that stomping on the brake affects the engines idle. It settles the idle below blow-up rpm numbers. Stalled at least once during the few "tests" I ran. Didn't want to mess around with it too much.

I am guessing this means I need to have a long hard look at the brake booster vacuum hose?

Thanks for your help, I'll let you know what I find.

The best way to sort out an air leak problem is with a smoke test. Have one done ASAP.
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1998 V70 AWD->FWD->AWD Turbo 215k+

That vacuum line is there and new. There is no change to the small amount of water around the injectors. The big hose is good; hooked up right with no holes or cracks.

It is like the gas pedal is slammed to the floor. The throttle plate and cable move freely. I don't know what the TPS does but unhooking it does not make a change. Do you know what a sympton of a bad sensor looks like?

Would there be any benefit to monitoring something while the engine is being cranked with no coil wire hooked up?

I would bet your IAC electrical connector is unplugged.

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1998 V70 AWD->FWD->AWD Turbo 215k+

Silver can by the vacuum tree, right? It is plugged in. Can this be tested?

Is the throttle connected correctly? How about the MAF?
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If you're not driving it "like its stolen," are you really driving?

They appear to be hooked up alright. Disconnecting MAF makes no difference. Not sure what I might have gotten screwed up around the throttle, but its like the gas pedal is hammered to the floor when I start this thing. The plate moves freely inside the throttle...

I figured maybe you didn't re-connect the linkage between the accelerator cable and the throttle plate.

Idle air valve should make a buzzing noise while its running. The vacuum line to the fuel pressure regulator (right under the fuel rail) is connected and the connector at the rail didn't split when you were moving stuff?

Not really sure what all would make it race, the other vacuum lines you've got the Air pump, the one to the air box, and there's one to the underside of the intake manifold. I think thats all. Then there should be another lager hose for EVAP and another for EGR. I think only the one to the FPR would cause any idle issues.

Maybe the throttle position sensor?
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If you're not driving it "like its stolen," are you really driving?

FPR vacuum line is connected. It is an old one that should be replaced (one of the originals with the rubber ends on plastic-like tubing). This was removed and reinstalled. The throttle position sensor has never been unplugged. The connector (female side) for the IAC valve looks a little suspicious. Sprayed it with a little battery cleaner and no change. Still suspicious though, but I don't know what an exact sympton of the not working at start-up would be. After start-up/immediate shut down, there is that light whirring noise from the throttle area. Is that the IAC?

Thanks