Problem starting up the engine

MartinP · Post by **MartinP** » Thu Jul 27, 2006 5:28 pm

Alright. You are talking about the biggest hoose there is, located at the bottom of this picture right?

Ally · Post by **Ally** » Thu Jul 27, 2006 5:41 pm

Yes, the biggest hose there is.

Here's another pic with the throttle body circled.

MartinP · Post by **MartinP** » Thu Jul 27, 2006 5:49 pm

Alright. I'll start off by restoring the idle valve. I'll post back within short.

MartinP · Post by **MartinP** » Thu Jul 27, 2006 6:49 pm

I put it back into place and strapped on some fresh hose clamps. The results? Well, it sure did a lot for the idle RPM, because it no is more or less rock solid stable 900RPM. Sure it's slightly higher when you've just braked in front of a red light, but it doesn't jump up and down like it used to. That is, atleast not yet.
Unfortunately the main problem resists. For a short moment though, I thought that it solved it because it ignited the engine 3 times in a row without a problem. Then came the usual problems. I try to ignite, but all I here is screeching and roaring from the engine, trying to power itself on. If I start pushing the pedal up and down a little bit, the sounds gets more lighter and sounds more like a cough. If I keep pushing, it finally ignites.

This however never happens if I make it a habit of always pressing the gas pedal a little bit before turning the key.
Well guys, what should I do next? Check inside the throttle body? Or check the temp sensor? Hm..either which I still have to remove the big hoose.

I just thought of the sparking plugs, could they have anything to do with the problem as I described it?

Ally · Post by **Ally** » Thu Jul 27, 2006 8:11 pm

If you're not sure of the service history it doesn't hurt to change spark plugs, distributor cap, rotor arm, HT leads. Will often make a noticeable difference even when nothing is really wrong with the running of the engine.

The big hose should come off really easily - just one giant hose clip. The temp sensor should also be reasonably easy to access and test.

Sounds like you're making progress though....

MartinP · Post by **MartinP** » Thu Jul 27, 2006 8:31 pm

Yes indeed I am !

Well, I'm going to my friend for the weekend so I guess I won't be testing that much at his place (unless we do it together

). If not, I'll do it on sunday and get back to you guys then.

Cheers and thanks again!

Martin

MartinP · Post by **MartinP** » Sat Jul 29, 2006 12:04 am

Well turns out I did two things in my car today along with my pal! Changed spark plugs and cleaned the throttle body (the two intakes).
What I didn't manage to access was the temp sensor because I really couldn't find it! Maybe because I don't know how it looks really, but I tried real hard and searched under the spark plug far to the left. I also all the other places, but the sensor remained nowhere to be found. Can someone pinpoint the location of it for me on my pic?

MartinP · Post by **MartinP** » Mon Jul 31, 2006 8:36 am

I've found something, but I'm not sure that it's the temp sensor. Is it?

martinholmesuk · Post by **martinholmesuk** » Mon Jul 31, 2006 1:12 pm

yes temp sensor. Looks odd on your engine as you lot's of other crap around it.

anyway that tells the ecu the temp and affects how much fuel it pumps for the injectors and if faulty you would have probs

MartinP · Post by **MartinP** » Mon Jul 31, 2006 4:18 pm

Yeah, well I'm replacing it in a couple of days. That is, as soon as Volvo gets one.

MartinP · Post by **MartinP** » Tue Aug 01, 2006 5:43 am

Ok, so the tempsensor is ordered at Volvo but it will take a couple of days and in the mean while I've been digging around at the local scrapyard and I found two 480's that still have their tempsensors mounted as so I'm wondering if it's worth it to pick a tempsensor up from a scrapyard instead of Volvo and thereby reducing the amound of days to wait and also the cost.
So, what do you guys think of this?

Oh, the two 480's are 480t -90 & 480ES -88

Ally · Post by **Ally** » Tue Aug 01, 2006 8:54 am

Ally wrote: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

The only difference between a B18E and a B18ES as I understand it is that the B18ES also has EGR (exhaust gas recirculation). So I'm assuming the temp sensor is the same as for the B18E.

If you check the ones in the cars in the scrapyard before getting them at least you'll have an idea if they're the right ones/working properly.

Have you tested the one that's on your car at the moment?

MartinP · Post by **MartinP** » Tue Aug 01, 2006 9:42 am

Yes I have, it showed me endless resistance which clearly shows that it's crappy and is causing all of my problems as a temp sensor isn't supposed to show that. (the temp. was somewhere between 10-20 C approx.)
Talked to a guy at a swedish 480 forum and he had the same problem as me and when we dismounted the temp sensor, to his suprise the coolant had corroded it so badly that there wasn't much of a temp sensor left. He replaced it and everything has been working great since then.
Hopefully, the same will go for me.

Ally · Post by **Ally** » Tue Aug 01, 2006 9:50 am

It's up to you then, If you've got the money to buy a new one at least you know it shouldn't be faulty...

MartinP · Post by **MartinP** » Tue Aug 01, 2006 9:58 am

Yeah, I guess. Buying one off the scrapyard would be faster as I don't have to wait and cheaper, but what if I get a faulty one? So what if the resistance is proper? It can still be broken and I really don't feel like changing temp sensors once in a week.
Besides, I was just told that 480 87 year's modell has a unique kind of temp sensor which is different from all the other year's. It gives me no choice but to wait. In the end, it will work out for the best I hope.
I'll post back as soon as I get it and know how it went.

MartinP · Post by **MartinP** » Mon Aug 28, 2006 9:12 pm

Sorry for not posting for such a long time folks.

Well, a lot has happened since the last time we spoke, including that I've replaced both the idle valve and the temp sensor. The result? It's still the same. I'm still having problem starting up the engine when it's cold. What's funny is that I got a tip the other day that the injectors could be the ones to blame so I bought a Injector cleaner to see if that would do any good, and it sure did. Well, I still had problems when it was cold, but now it didn't require as much work as it used to in order to get it within a normal idling RPM range (~800). Today, I couldn't get it working so I pushed down the gas pedal while shifting and I was back on track after about 5 metres. I know! The only thing I did was to drive out on the road and when I held down the clutch, it was gone. Sure, it was struggling to stay alive (300 RPM), but it didn't gave in like it used to.
I'm really running out of ideas and I don't know where to go next. What about the earth connectors?

MartinP · Post by **MartinP** » Sun Sep 03, 2006 7:28 pm

I finally solved it yesterday

Turned out to be the ECU that had gone bad. I opened it up and the voltage regulator had melted! Is bought a new ECU off the scrapyard and it's been great ever since. After 1 Â½ month of hell the nightmare is finally over. A reminder to all of you out there struggling to fix your starting or idle problems, check the ECU!

iimomar · Post by **iimomar** » Tue Sep 18, 2012 9:23 pm

Hi,

I've read in this post many advise regarding how to check a 3-pin throttle sensor... but regarding a 6-pin sensor? Any advise?

Cheers!

Volvo 480 Club Europe

Problem starting up the engine

Re: Problem starting up the engine