Recently acquired 1989 740/B230E rough starting

Hi all,

Is there a common fault which causes rough cold starting which is quickly cured by a couple of blips on the throttle?

The car conked out on a run recently due to the black hose just beside (part of?) the auxiliary air valve disconnecting itself, so I thought I'd better find out what the AAV actually is - could it possibly be this at fault? Dirty injector(s)? Worth putting a drop of injector cleaner through it?

Thanks,

Si

Reply to
Mungo "two sheds" Toadfoot
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On a 16 year old car, even one well maintained where do you start on bits that simply get old. Presumabley it has been well serviced?

What is the ignition & injection system? Dont know where you are Mungo. If the UK your beastie would have been on the cusp of going from the manual K-jet mechanical injection system to the more sophisticated electronic injection with lambda sond et-al. if the latter you will have an OBD outlet to check for error codes which may be the best place to start.

If K-jet then (and some of this would relate to post k-jet era):

Do the easiest and cheapest bits first.

My first Q would be to ask if the Rotor arm, distributor cap plug and king leads have ever been changed,. If not then the sooner the better cos the chances are the posts in the distrib cap are worn to buggers,. Next make sure you are running Bosch/volvo plugs. Check the colour to make sure engine is is set up ok. I dont know why but the B200e and b230e engines in particular do not seem to like NGK or Champeen plugs. Bosh plugs rule ok for these engines.

After that a can of good injector cleaner into 1/4 tank of juice and take for a blast.

By the time we had done this on ours we were cooking, now sadly we have another gremlin of the zero to 60mph acceleration in an eternity (18 seconds actually).

Andy

Reply to
Andy

Yes. I just wondered if there was something along these lines that went wrong with all 740s, like the headlinings and gauges.

It has been serviced religiously. Also, the previous owner told me that he had had a problem with the engine cutting out so pretty much everything to do with the ignition has been renewed - distributor, ignition unit...I'm not

100% sure about the leads (King/HT) though because the caps at least do look quite old.

I think it's the "continuous injection system".

Dont know where you are

My manual says that the contiuous injection system is well-proven with little to go wring so I assume it's older than the lambda sond job.

I will check to make sure they're new.

Next make sure you are running Bosch/volvo plugs. Check

Colour looks ok but they are Champion plugs, if I remember rightly. Something else to check

Did that today.

That's not good. I hope you find the reason for it soon!

Si

Reply to
Mungo "two sheds" Toadfoot

I still didn't say! Yes, UK.

Si

Reply to
Mungo "two sheds" Toadfoot

King lead should be checked. They have been known to rub near near the bulkhead and give an intermittant short. Wait until it gets dark, fire up car and have a squiz. I would have thought the king lead would have been replaced when others replaced but you never know. If it looks different or a bit old then play safe and change.

The Ovlov garage where our 740 has been serviced have always maintained (as has the 740 mechanic who has always done the servicing) that Champion and NGK plugs cause heaps of problems on the 740. They have never been able to tell me why but have not I don't believe been trying to punt Volvo/Bosch plugs at a premium price. I can't see why it should make a difference but maybe somebody else has come across this.

Interested if you noticed any difference after the fuel injector cleaner. I have been told by Volvo to do that to our 740 to help find/cure our poor accelleration issue - they seem to swear by the stuff but I have always been dubious. Will keep you posted on this prob.

Lying in bed It occured to me that another thing that needs checking early on is the throttle housing and also the big black idle adjusting screw that sits under the inlet manifold (you can't miss it it has a knurled thumb screw and is about 1/2 inch in dia.

The throttle housing and butterfly valve just get a bit gummed up and need cleaning. By the sound of things you will not have to worry about any Air Mass Meters like on the post 90 models here with Lambda Sond.

The big black screwey thing gets a a coating of shitty carbon on it. Unscrew and pull out, it may be stiff and not want to pull out even when you have finished unscrewing, there is an 'O' ring holding it tight, give it a tug. When you put back get enginw warm and use to adjust tickover to what you are comfortable with at arounf 850rpm.

Andy

Reply to
Andy

Whilst I had not noticed it causing rough cold starting on our similarly specked Ovlov we have had issues with leakng injector seals which caused an uneven tickover. We have had to replace twice now in 16 years, the rubber (or whatever they are made of) goes hard and lets a smidgeon of air in. To check spray WD40 over each of the injector bases and if the tickover suddenly appears smoother then get replacing. Simple to do but be careful of little washers that easily fall off when you remove. Only cost a couple of quids.

Andy

Reply to
Andy

Thanks again for the reply. I think I've discovered the source of my problem: reading through the Haynes manual I discovered a section on the starting procedure and it seems I am supposed to step on the accelerator once before starting the car to set the choke. having done this it starts properly first time, every time.

I also own a newer car which likes starting without any touch of the accelerator whatsoever so I'd got used to this.

Fingers crossed, it's working!

Si

Reply to
Mungo "two sheds" Toadfoot

Thanks. I'm noting all these things for future reference with the hope that I'll never need them.

Si

Reply to
Mungo "two sheds" Toadfoot

.....Although the user's handbook says this is not necessary. Whatever, it works.

Si

Reply to
Mungo "two sheds" Toadfoot

If you definately have a NON carbed B200 / B230, then pressing the pedal before cold start should not make the blindest bit of difference to start performance, as fuel injection does not have a choke, nor does it have a mechanical fast idle linkage like a carb does.

Tim..

Reply to
Tim..

This is what I thunked, but it does make all the difference to the starting. I'm going to have to have a closer look at it tomorrow - I haven't had time recently. It's definitely the B230E engine but I don't know if they had carbs, injection, or either.

Si

Reply to
Mungo "two sheds" Toadfoot

Injection is the order of the day, without Lambda Sond and without catalyser. It does have a start injector however.

All the best, Peter.

Reply to
Peter K L Milnes

If that is the case, then you may have a dirty and sticking throttle body butterfly or linkage that is holding the throttle open partially making it hard to start. When you depress and release the throttle it allows the butterfly to snap back into place.

A warped throttle body could do the same sort of thing- allowing the throttle to set in one position when the car was hot and not be correctly placed when the car gets cold from sitting overnight (this one is a stretch becasue the throttle body doesn't get that warm).

Adjust the throttle stop screw, idle adjustment, and throttle linkage and cable as appropriate for your model and be sure tha tthe cable and related parts are working smoothly. When I was going through mine I found that the cable was incorrectly adjusted and only allowed about

85-90% throttle! It could be that yours is working the other way and holding the throttle open a bit...

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Reply to
Randy G.

...and one more thing- check the function and adjustment of the throttle position switch. __ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Reply to
Randy G.

My understanding is that some (many? few?) ECUs treat the pedal depression before starting the way a carb does, enrichening the mixture at the driver's request. I believe most or all also treat full throttle depression during starting as a desire to air out a flooded intake and will reduce the injected fuel in response.

Mike

Reply to
Michael Pardee

Most info you will ever need is contained in either the VolvoSpy or Volvoclub UK websites.

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and this is the link to the 700 FAQ's
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in there is info on changing the injector seals, cleaning the throttle housing etc.http://www.volvospy.com/The Brickboard is also good but I think the FAQ's are now incorporated within VolvoclubUK site.http://www.brickboard.com/http://www.brickboard.com/FAQ/700-900/Volvospeed is quite good for 850/V70/V40 ilks
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U find useful

Andy

Reply to
Andy

accelerator

No pedal depression pre-start wont make any difference to what the ECU does. All it reads is pedal position, coolant / air temperatures, rpm and then reads a suitable injector duration from its look up tables.

On one or two earlier fuel injected Toyota's and Nissans there was a wax-stat for additonal fast idle enhancement which did require pedal movement to set them, but was not connected to the ecu and fuelling amounts in any way.

Tim..

Reply to
Tim..

^^^^^^^^^ yes, thermo time switch controlled. Doesnt function above ~3deg's C anyways though.

Tim..

Reply to
Tim..

Ah yes, that could be it. I'll check everything when I get time. It does idle a bit fast when it's hot so that could explain that too, rather than the idle speed being set too fast.

Thanks,

Si

Reply to
Mungo "two sheds" Toadfoot

All saved for future reference - many thanks.

Si

Reply to
Mungo "two sheds" Toadfoot

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