An interesting problem this weekend

Post by **Ozark Lee** » 03 Jan 2010, 18:00

I decided to go to the cabin on the lake this weekend and we drove the '94 N/A. When we left the city house it was showing 4 degrees F on the dashboard display.

Once I cleared the city I stabbed on the cruise and after about 20 miles of fairly level terrain I came to the realization that the throttle was stuck. I turned the cruise off but the car kept accelerating. When I pushed in the clutch the engine wanted to redline.

The brakes on these cars are amazing so I just used the brakes to slow down. I pulled onto the shoulder at about 50 MPH and then I pulled the key back to position I and then put in the clutch and got the car stopped without incident. After about 6 stabs on the accelerator with my foot it all freed up again and I restarted and went back on my merry way.

I have not cleaned the throttle body on the '94 in several years but I have jammed the cold air intake to the cold air side. I think the throttle body may have iced up. I think I will clean the throttle body soon but the suspected icing may be an unintentional side effect of the air box modification.

...Lee

toddv850glt · Post by **toddv850glt** » 03 Jan 2010, 19:39

I noticed ice in the intake system just before the throttle body and switched the air box mod back to normal and I hope it helps. Im lucky I changed mine back before that happened to me. I have been sucking in to much cold moist air and I think that was the problem. It has been in the negative numbers here in Minnesota. Glad thinks turned out good for you, I would of been panicing out. Check to see if you have ice in the intake tube. I have also noticed water and creamy substance in my tube comming from the oil separator.

Post by **polskamafia mjl** » 03 Jan 2010, 22:52

Here in central PA the temperature doesn't get that cold, so far the lowest has been 20 F. I'm thinking there's little chance of my throttle icing up this winter.

valvster · Post by **valvster** » 04 Jan 2010, 04:11

I did the airbox mod yesterday by jamming in a piece of wood to hold the flap in the cold position and took it for a 200km test drive today. Can't beleive how much better the car performed up through the hills freeway, especially overtaking at high speeds.
My odometer is cactus but I reckon I used 4 - 6 litres less fuel than I normally do for this round trip. All the while I'm thinking how could Porsche get it so wrong when setting up these engines for Volvo by putting in this idiot flap....I think you may have found the answer.
Luckily we rarely get freezing temps in Sth Australia so my specially calibrated bit of stick will remain, I also dumped the snow guard.

cheersmerryxmashappynewyear....Valvster

Post by **Volvo_240_Atari_2600** » 04 Jan 2010, 05:12

Question to Ozark:

Sorry to hijack your thread but I do have a legit question on the mod thing as well as something else that I think may or may not be related.

In doing that airbox mod, did you remove the flex tube and seal off the opening for the flex tube to the exhaust manifold? Or did you just do the mod w/o removing that tube?

I did the mod on my wife's 98 v70 na back in the summer but I never removed the tube. I meant to for months but never got around to it. Can't say I can rejoyce in fuel savings like many here seem to have, however in a post in August I had mentioned how I did major svc on he car while she and the kids were out of the country.

I went through the changing of plugs and dist cap and rotor w/ throttle body cleaning, maf cleaning etc... I did not change the BOUGI cords that I installed in October 2007. (Dist cap and Rotor were also aftermarket that I got from FCP)

The plugs I initially used were Bosch Platinums (WRONG)
The car did not take those very well and it coughed and choked until I replaced them with VOLVO 4 prong oem's from FCP. That was a few days later. All went back to normal until about a month or so ago. The car started to stall, and choke/buck sometimes while coming to a stop light and buck at acceleration when the light turn green.

Two weeks ago I took the car for a few days and ran the codes.... I have had P0445 for a year now (the one that indicates fuel or fuel/vacum loss?) Haven't gotten around to looking into the vacum lines as yet.
I was surprised to see P0302-303 and 304 along with I think it was P0171 (not sure if the number is right) but its the one for the MAF sensor.

Remedy:
seafoam
Maf and maf contact cleaning. (yes, I did use the correct cleaners)
cleared the codes.

So far... first few days no dramatic changes... Car did hesitate on me twice. (P0445 was the only code to return about 3 weeks ago)

Towards the end of my few days of usage, I eliminated the hose, mind you I did the mod keeping the cold air intake open since August. I sis also seal the opening for the hot air side once the hose was removed.

Lets just say that the P0445 code would normally return after about two days from being cleared, maybe three.

Today, over a week later the car does not hesitate, stall or buck... As if there were no problems ever. Neither one of those codes ever returned and the car seems to run fine.

I read some threads here on the codes and remedies I mentioned above.
I did order new OEM plugs again, as a just in case and a new BOSCH cap and rotor as well as a new set of BOUGI cords from FCP... should arrive today.

Has anyone had a similar experience?
What about the box mod? Did I do the correct thing in removing that hose?

57buzzard · Post by **57buzzard** » 04 Jan 2010, 16:31

I stole the hose from one of the 240s and ran it from the hot air side as far as it would go, just below the battery area.

Post by **confused_al** » 04 Jan 2010, 17:35

Now I know why these MB engines' all have their intake at the back of the engine (right by the firewall) by running an extra long pipe from the front to the back, it is to prevent TB got frozen up!

Post by **RobTheModd** » 04 Jan 2010, 18:49

Volvo_240_Atari_2600 wrote:Question to Ozark:

Sorry to hijack your thread but I do have a legit question on the mod thing as well as something else that I think may or may not be related.

In doing that airbox mod, did you remove the flex tube and seal off the opening for the flex tube to the exhaust manifold? Or did you just do the mod w/o removing that tube?
\

I think I can answer that depending on which car your asking him about, or which one he told me he did it to.
he left the silver tube attached. lol
as did i.

BTW! gotta say it... LOVE TO LIVE IN FL where I dont have to worry about this. coldest it gets is 30. also noticed the red light next to the read out screen...... i guess it tells me when its below freezing outside? lol

Post by **vegasjetskier** » 04 Jan 2010, 19:40

RobTheModd wrote: also noticed the red light next to the read out screen...... i guess it tells me when its below freezing outside? lol

I don't know - mine came on last night but the temp only read 34 degrees.

Post by **jblackburn** » 04 Jan 2010, 19:55

It's to warn you the roads might be icy. Interestingly enough, it doesn't even bother to come on when it was 10 outside this morning.