Problem starting up the engine

Ally · Post by **Ally** » Wed Jul 26, 2006 8:17 pm

MartinP wrote:The ones on the TPS didn't show any resistance at all. At first, I thought that the DMM was freaking out so I tried a piece of metall on the engine, still nothing. I went through the entire range (from K ohm -> M Ohm), but still it didn't show a thing. It didn't matter if I checked the resistance between the outer pins or the outer and the center one.

By "it didn't show a thing" I take it you mean a reading of zero ohms. If this is correct, and you're confident you were using the meter correctly then this suggests the sensor has completely short circuited inside the casing. If you mean infinitely high resistance (beyond range of meter) then it suggests the sensor is effectively open circuit. Either way it sounds like the TPS is dead.

Answer:- New throttle position sensor (or one from a scrapyard).

The readings you were getting from the cable are effectively readings across pins on the ECU and don't help with this problem. These readings would not be expected to change as you move the throttle since the position sensor in not connected to the cable.

MartinP · Post by **MartinP** » Wed Jul 26, 2006 8:40 pm

I know I checked it twice, but just to be sure, I'll do it again right now. I'll post back in 10-15 min.

MartinP · Post by **MartinP** » Wed Jul 26, 2006 9:01 pm

Ok, here are the results (drums):

Assuming that the left one is 1 and the right 3:

1&2 (closed throttle): no connection
fully opened throttle: 1.3 ohm (no I'm not kidding)

1&3 (closed throttle): no connection
(fully opened) : no connection

3&2 (closed throttle): 0.05 ohm
(fully opened) : no connection

There. I checked it twice again so this time, the results are true.

What do with this?

wreeve · Post by **wreeve** » Thu Jul 27, 2006 9:13 am

I don't know these cars very well but what you have measured seems like it's just a throttle position "SWITCH" and not an analogue sensor.

If your car should have a switch it appears to be working fine as all it does is signal to the ECU three possible states:
1/ Throttle closed
2/ Throttle wide open (WOT)
3/ Somewhere in-between

Keep well,

Will

Ally · Post by **Ally** » Thu Jul 27, 2006 10:31 am

OK, I've done the same as you with the sensor on my 1.7 and come up with what are basically the same results.

â€¢ Pins 1&2 throttle closed: no connection
â€¢ Pins 1&2 throttle fully open: 1.9 ohms
â€¢ Pins 3&2 throttle closed: 0.2 ohm
â€¢ Pins 3&2 throttle fully open: no connection
â€¢ Pins 1&3 in either state: no connection

As I said before I wasn't sure of the required values for your sensor, but it appears the sensor on the 1.7 engine is just a switch and it does make a clicking sound just as you start to open the throttle.

It also looks like it's working fine.

Question is what to try next as you still have your starting problem!

I'm not sure what to check next...

Is the problem only present when the engine is cold?

Once started is the idle speed OK (800 - 900 RPM) and is it steady?

MartinP · Post by **MartinP** » Thu Jul 27, 2006 11:32 am

Once started is the idle speed OK (800 - 900 RPM) and is it steady?

My idle RPM are always a bit to low, yeah somewhere inbetween 800-900 sounds about right.

I got some good advice from some guys at a swedish forum and they were sure that the cause of my problem was the (don't know if this sounds right in english because I really don't know what it's called, but here goes) tempsensor. It's the one sitting underneath the 1:st sparkplug (if seen from the right). I looks a bit like a sparkplug, but it has 2 pins. Don't ask me because I don't exactly know what it does.

Another thing they also thought could be the cause was the "idling engine" (that's what it's called in swedish). This might not be the correct name for it so here's a pic to show you what I mean:
http://www.geting.se/viewimage.php?image=IMG_0962.jpg#

I'm gonna clean the "idling engine" today and really soak it with 5-56 to give it that good new look and hopefully that will solve things. If not, the tempsensor is the next step.
What do you guys think about this?

Brasco · Post by **Brasco** » Thu Jul 27, 2006 12:28 pm

It's called the "Idle Valve" here. We usually suggest giving it a clean out with carb (as in "carburetta") cleaner.

http://volvo480.northernscum.org.uk/for ... php?t=9227

http://volvo480.northernscum.org.uk/for ... php?t=7808

http://volvo480.northernscum.org.uk/for ... php?t=7590

http://volvo480.northernscum.org.uk/for ... php?t=8441

etc...

wreeve · Post by **wreeve** » Thu Jul 27, 2006 12:34 pm

If it's the temp sensor I would suspect that the problem would either get worse or better when the engine was nice and hot.

Ally · Post by **Ally** » Thu Jul 27, 2006 12:59 pm

If I understand correctly your idle speed is about right. Yeah, I'd go with giving the idle control valve a good clean and see what happens.

It can be tested in a similar way to the TPS but there are 3 versions of the idle control valve depending on engine.

B18E = 44 ohms
B18EP, B18FP, B20F = 8 ohms
B18F, B18FT = 20 ohms

If you're not sure which engine is yours you can find out using the VIN (chassis number) reader on the main club site http://www.volvo-480-europe.org/cardata/vin/vin.php

Test data for the temperature sensor also depends on engine and must be checked with the engine cold (20Â°C).

B18E = 290Â±20 ohms
All other engines = 2500Â±300 ohms

You'll need to unplug the cables from the components to check them and remember it's the component your testing, not the cable. Both components only have two pins so there can't be any confusion in what you're measuring.

Just thinking about your problem, if your idle speed is OK and the engine starts with a little throttle applied then is there really a problem? Doesn't seem to me like it really matters...

MartinP · Post by **MartinP** » Thu Jul 27, 2006 2:10 pm

Yeah, you might think of it like that but it really is annoying when engine won't go on without a "kick" from the good 'ol foot. One problem sooner or later results in more problems, usually.

f your idle speed is OK and the engine starts with a little throttle applied then is there really a problem? Doesn't seem to me like it really matters... Don't Know or Don't Understand

Well, my idle speed isn't always ok, that's the thing. I get the same prob. that most of you guys do. It sometimes revs up to like 1.4-1.5k RPM's and then goes down to 800-900 again.

Well, after thinking about it I really think that cleaning the idle valve can do a lot of good. I'm on it and post back as soon as I know anything.

Oh, and my engine is a B18ES.

MartinP · Post by **MartinP** » Thu Jul 27, 2006 3:17 pm

I just brought home the idle valve, but I really can't figure out how do open it. I guess that I have to open it inorder to clean it, right?

wreeve · Post by **wreeve** » Thu Jul 27, 2006 3:42 pm

Don't open it! Just squirt loads of carb cleaner through it to get the crap out. Then I usually give it a spray of WD40 for luck.

Will

martinholmesuk · Post by **martinholmesuk** » Thu Jul 27, 2006 3:42 pm

Don't even try to open it up. Hard to do and harder to have it working again.

get some carb cleaner from your local car store and spray the insides and then drain it out.

MartinP · Post by **MartinP** » Thu Jul 27, 2006 4:20 pm

Roger. This is what I'll use, it's practically the same thing.

So all I need to do is to spray shitloads of it through the "black" hole?

MartinP · Post by **MartinP** » Thu Jul 27, 2006 4:29 pm

Ok, done. How long should it stand before cleaning up and putting back?

wreeve · Post by **wreeve** » Thu Jul 27, 2006 4:33 pm

I've not done it on the 480 yet but done it on lots of cars. I just stick one hand over one end, squirt in loads of carb cleaner in the other, cover the other end with another hand and shake. Empty, and repeat until the liquid you empty out is as clean as it is when you squirt it in. A quick squirt of WD40 then straight back on the car!

MartinP · Post by **MartinP** » Thu Jul 27, 2006 4:36 pm

Oh, that's how you do it. I just squirted it right through. Oh well, i'm not it. Thanks again!

Oh, doesn't it have to dry for a while before putting it back?

wreeve · Post by **wreeve** » Thu Jul 27, 2006 4:46 pm

If your carb cleaner is the same as mine it evaporates off pretty quickly. About a minute and its bone dry.
Not sure if the 480 is any different by on Vauxhalls the throttle body gets gummed up as well, might be worth cleaning around the edge of the plate which opens/closes with the throttle. I've seen a build up so bad that it stops the plate sealing shut when the throttle is closed.
These are all things I need to do on my 480 when the evenings cool down a bit!

I've also seen bodges like holes drilled in the throttle place to cure problems such as yours!

Keep well,

Will

MartinP · Post by **MartinP** » Thu Jul 27, 2006 4:57 pm

Thanks for your replies Will, but unfortunately I don't know where this throttle body is located. could you perhaps point it out on the picture I posted earlier on?

Well, I cleaned the idle valve with my 5-56 which is basically kind of an oil because it really feels moisty afterwards. Should I wait or is it safe to mount it back?

wreeve · Post by **wreeve** » Thu Jul 27, 2006 5:23 pm

Look at the photo Ally posted. That red arrow points to the throttle body/plate. The throttle position switch is mounted onto the plate spindle. What you need to do is pull off that big black pipe going to it and you should see a metal round plate which open with the throttle, clean this up if it looks gummed up.
My carb clean is a bit like petrol, evaporate very quickly. If you spray some on the floor takes about 10 seconds to evaporate completely. Iâ€™ve also used break disc cleaner in the past although I suspect it doesnâ€™t do rubber parts much good.

Keep well,

Will