A Real Head Scratcher For You Volvo Gurus

[Seagrams]

So what did you do to the intake lately?

who me?

asides from the K&N drop-in filter nothing....

Well except of course for the addition of a hamster-driven paddle wheel to further encourage increased airflow, a two toned flame job on the airbox itself and lots of stickers–stickers are important for that extra 10-15 bhp :lol:

[Seagrams]

The R ECU should give you 10.5, but on my turbo cars I never saw the supposed 9.6, usually more like 7-8. Check the wastegate actuator, might need more preload.

Or, just run a boost controller at 10-12 psi or whatever your preference is. The BCS is nice in terms of keeping it stock, but M4.3's boost control is primitive and usually pretty sporadic.

i am running an MBC and am hitting 10+psi no prob. Before i got it, i did try preloading the wastegate actuator (by shortening the rod) and i didn't see anymore boost, it just kicked in harder.

[Fishey]

check the intake and the PCV.

[supra_stephe]

check ALL your vacuum lines, every inch.

[Seagrams]

check the intake and the PCV.

for what? PCV is inspected every service. maybe i'll go outside and try the paper suction test. what to check on intake?

The only vac lines i haven't replaced are the hard white plastic one, and i think there is a short little section going to the EGR valve. Everything else including elbows are new and i get a money 20 in Hg at idle in park, 22 in Hg while cruising with my foot off the gas.

[lookforjoe]

What's up with you guys? Didn't you read his post?

check ALL your vacuum lines, every inch.

for what? PCV is inspected every service. maybe i'll go outside and try the paper suction test. what to check on intake?

The only vac lines i haven't replaced are the hard white plastic one, and i think there is a short little section going to the EGR valve. Everything else including elbows are new and i get a money 20 in Hg at idle in park, 22 in Hg while cruising with my foot off the gas.

You don't get 20in Hg @ idle w/ vacuum leaks.

[Seagrams]

Thank god someone said it. I'm not one to sh*t on anyone trying to help by offering up some advice, but golly. The intake is one of the simplest things on the car, plus if that was the problem how would a MBC enable me to see all that boost again??? I'm honestly surprised that nobody has said "stage 0" yet..... cause if they did, i'd twist off their head and spike it onto the floor of a nightmare they couldn't even imagine . Haven't had time to check anything yet (went to the gym after work and then got an alarm for a chimney fire) but i did manage to source a test light.... onwards and downwards

[Fishey]

Thank god someone said it. I'm not one to sh*t on anyone trying to help by offering up some advice, but golly. The intake is one of the simplest things on the car, plus if that was the problem how would a MBC enable me to see all that boost again??? I'm honestly surprised that nobody has said "stage 0" yet..... cause if they did, i'd twist off their head and spike it onto the floor of a nightmare they couldn't even imagine . Haven't had time to check anything yet (went to the gym after work and then got an alarm for a chimney fire) but i did manage to source a test light.... onwards and downwards

Learn how the system works and you might understand how and why it would put a car into limp mode. Its one of the biggest issues we have run into with making a cold air intake system for the Volvo 850 Turbo's. What you have said sound exactly like what happens when it becomes unplugged or blocked. The car will only boost up for a few seconds and then it gets cut down by the ECU.

KTHXBYE

-Fishey

[theForgottenone]

Learn how the system works and you might understand how and why it would put a car into limp mode. Its one of the biggest issues we have run into with making a cold air intake system for the Volvo 850 Turbo's. What you have said sound exactly like what happens when it becomes unplugged or blocked. The car will only boost up for a few seconds and then it gets cut down by the ECU.

KTHXBYE

-Fishey

So how a drop in K&N air filter put a car in limp mode :rolleyes:

[TurboTim]

Did you check what I said. Your not checking the main part of the system that controls boost so you are just wasting time. Just so you know you can still see 20inches of vacuum with vacuum leaks. The idle air control motor just closes it self off alittle to compansate for the added air.

[Seagrams]

Did you check what I said. Your not checking the main part of the system that controls boost so you are just wasting time. Just so you know you can still see 20inches of vacuum with vacuum leaks. The idle air control motor just closes it self off alittle to compansate for the added air.

Agreed, Like I said i just got a test light last night and haven't had time to do it yet.... Tim your advice has been some of the soundest yet, i plan on fully investigating your idea as soon as i get the time (this weekend) since it makes the most sense. +1

Ok since apparently Fishey thinks i don't understand how the air intake on my car works let me just see if i got this straight.... You're saying that you think my car is in limp mode because some part of my intake system is either blocked or unplugged ? you've got to be kidding me. if your attempts at being a condescending dick weren't so thinly veiled i'd think you're the one who's unplugged . Every part of the intake system from where it takes in air in front of the rad to where it hooks up to the compressor inlet is connected and clear, except for the vacuum plug i put over the BCS intake nipple while i have the MBC hooked up. How do i know, i had to take it out to do a pressure test. Did I hook it back up properly, i certainly hope so otherwise i shouldn't be driving cars let alone working on them, Plus like i've said a gajillion times, I've had this problem since i got the car.... i really just can't go over all this again read the original post.

Learn how to read what i've written before you decide to join me for a dance in the six-sided ring of fire.

Anyway if you're gonna be a dick, fine. I don't care, this isn't russia, just don't think i'm gonna lay down and let you give it to me by implying i don't know how four feet of plastic piping works GOD!!

To those who've helped, thanks much, otherwise....

take it deep

more on progress later.

[Fishey]

Agreed, Like I said i just got a test light last night and haven't had time to do it yet.... Tim your advice has been some of the soundest yet, i plan on fully investigating your idea as soon as i get the time (this weekend) since it makes the most sense. +1

Ok since apparently Fishey thinks i don't understand how the air intake on my car works let me just see if i got this straight.... You're saying that you think my car is in limp mode because some part of my intake system is either blocked or unplugged ? you've got to be kidding me. if your attempts at being a condescending dick weren't so thinly veiled i'd think you're the one who's unplugged . Every part of the intake system from where it takes in air in front of the rad to where it hooks up to the compressor inlet is connected and clear, except for the vacuum plug i put over the BCS intake nipple while i have the MBC hooked up. How do i know, i had to take it out to do a pressure test. Did I hook it back up properly, i certainly hope so otherwise i shouldn't be driving cars let alone working on them, Plus like

[Fishey]

Agreed, Like I said i just got a test light last night and haven't had time to do it yet.... Tim your advice has been some of the soundest yet, i plan on fully investigating your idea as soon as i get the time (this weekend) since it makes the most sense. +1

Ok since apparently Fishey thinks i don't understand how the air intake on my car works let me just see if i got this straight.... You're saying that you think my car is in limp mode because some part of my intake system is either blocked or unplugged ? you've got to be kidding me. if your attempts at being a condescending dick weren't so thinly veiled i'd think you're the one who's unplugged . Every part of the intake system from where it takes in air in front of the rad to where it hooks up to the compressor inlet is connected and clear, except for the vacuum plug i put over the BCS intake nipple while i have the MBC hooked up. How do i know, i had to take it out to do a pressure test. Did I hook it back up properly, i certainly hope so otherwise i shouldn't be driving cars let alone working on them, Plus like i've said a gajillion times, I've had this problem since i got the car.... i really just can't go over all this again read the original post.

Learn how to read what i've written before you decide to join me for a dance in the six-sided ring of fire.

Anyway if you're gonna be a dick, fine. I don't care, this isn't russia, just don't think i'm gonna lay down and let you give it to me by implying i don't know how four feet of plastic piping works GOD!!

To those who've helped, thanks much, otherwise....

take it deep

more on progress later.

Hey,

Check the PCV where it comes into the intake is all I am saying.. I have had similar effects to what your talking about when messing with it and thats why I am suggesting it.

-Your Pal

Fishey

[Seagrams]

You know the 2 wires that go to the boost solenoid. Just hook a test light up to it and you should see a duty cycle and the light flashing as you boost. You can probably even do this with the car just brake boosting. Then when you find out that doesnt work. I dont think it will.

Ok so i hooked up the test light, braked boosted and saw the duty cycle (the light flashed on and off rapidly). So I don't think that's the problem there. Next I cracked open my spare BCS and saw how it worked. It's remarkably simple; I'll post pics up in a separate topic later. Once i figured out how it worked i hooked some wires up to it and touched them to the battery. BCS functioned normally. Did the same to the BCS i have on the car currently, and it too functioned properly with 12V applied (keep in mind both BCS gave me the same 5 psi result.) So now i'm stymied....

BTW Tom's Endlinks made my front end tight as a 12 year old, I'd say it made an 80-110% improvement, Needless to say I'm VERY pleased !!!

Fishey, as far as that hose goes it's in good shape, (not cracked) and the vac elbow that connects there is maybe 4 months old. Hussein (lookforjoe) said in another post by Dongle I think that that hose wouldn't necessarily affect boost, i kinda forget what he said exactly but i'm sure he'll post or I'll find the link. But word, that suggestion is much better/ clearer than 'check your intake !!! I'm not sure if it's the culprit, but hey if it happened to you, then it's something i'll keep in mind

Gosh the more testing i do the more I think something much smaller and more annoying is going on here. I think my next step is to further investigate/retest the wastegate, Since i've pretty much ruled out the BCS, seeing how it actually works leads me back to the actuator diaphram on the wastegate. More TK

Thanks guys , keep 'em coming, I can almost smell a solution :lol:

[lookforjoe]

Ok so i hooked up the test light, braked boosted and saw the duty cycle (the light flashed on and off rapidly). So I don't think that's the problem there. Next I cracked open my spare BCS and saw how it worked. It's remarkably simple; I'll post pics up in a separate topic later. Once i figured out how it worked i hooked some wires up to it and touched them to the battery. BCS functioned normally. Did the same to the BCS i have on the car currently, and it too functioned properly with 12V applied (keep in mind both BCS gave me the same 5 psi result.) So now i'm stymied....

BTW Tom's Endlinks made my front end tight as a 12 year old, I'd say it made an 80-110% improvement, Needless to say I'm VERY pleased !!!

Fishey, as far as that hose goes it's in good shape, (not cracked) and the vac elbow that connects there is maybe 4 months old. Hussein (lookforjoe) said in another post by Dongle I think that that hose wouldn't necessarily affect boost, i kinda forget what he said exactly but i'm sure he'll post or I'll find the link. But word, that suggestion is much better/ clearer than 'check your intake !!! I'm not sure if it's the culprit, but hey if it happened to you, then it's something i'll keep in mind

Gosh the more testing i do the more I think something much smaller and more annoying is going on here. I think my next step is to further investigate/retest the wastegate, Since i've pretty much ruled out the BCS, seeing how it actually works leads me back to the actuator diaphram on the wastegate. More TK

Thanks guys , keep 'em coming, I can almost smell a solution

Stupid question perhaps - but is the lower BCS hose (18) connected to the underside nipple at the top of the inlet hose, and have you checked to confirm it's not restricted? If the BCS can't vent, you won't get the boost increase...