Loss of power and misfiring MAF?

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eddieh
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Loss of power and misfiring MAF?

Post by eddieh »

a 1985 water cooled 1.9l engine

Started running really badly. as soon as under strain such as any hill it misfired and lost power massively. Mechanic unable to source the problem. Friend suggested to me that this is consistent with a faulty MAF. Is this likely to be the case? This continued for about 500 miles then suddenly it is running perfectly again and has done so for nearly 300 miles.

I have been surprised that despite the misfiring, it seemed to use no more fuel which would seem consistent with the MAF.

I am no mechanic but is there any advice that I can pass on to my mechanic?

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bigbadbob76
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Re: Loss of power and misfiring MAF?

Post by bigbadbob76 »

What engine have u got in the van? 1.9 watercooled petrol? They are usually carburettor fueled so don't have a MAF sensor. If you have the rare 1.9 petrol fuel injected model then maybe you do have a MAF sensor.


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eddieh
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Re: Loss of power and misfiring MAF?

Post by eddieh »

I really don't know but i suspect not the fuel injection. We certainly have a carburettor. Would it be a good idea to just replace that. We have a history of poor running on random days. Prior to this last problem it has invariably run fine the day after running poorly.

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bigbadbob76
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Re: Loss of power and misfiring MAF?

Post by bigbadbob76 »

Ok, if you have a carb you don't have injection and therefore no MAF sensor.
I would get a carb rebuild kit from Brickwerks and get your mechanic to refurb your carb.
He could also check the timing and check for air leaks and dirt in the fuel filter. but i wouldn't like to teach him his job. Hahaha...



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eddieh
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Re: Loss of power and misfiring MAF?

Post by eddieh »

Thank you Bigbadbob. I think all these things have been checked. He put in a transparent fuel filter over a year ago and there is no sign of dirt in it.

JeffRoo
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Re: Loss of power and misfiring MAF?

Post by JeffRoo »

Hi, I had a similar thing with my 1.9dg not injection when we were in the Outer Hebrides. Was just living with it whilst up there, but 45mph on the motorway home was enough!
Changed the fuel filter, no change, fiddled with things, no change. Thought it might be the vacuum advance so started to live with it for the time between motorway services.
I then remembered I had a full set of new HT leads. That was it I said to the missus, I’m going to give this one last shot and change the leads.
Once leads were changed, all perfect!

So my advice? Change the HT leads before attempting anything else, I forgot my rule of thumb. “When fault finding, start with the simple things first”

Best of luck :ok
84 Caravelle 1.9DG

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R0B
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Re: Loss of power and misfiring MAF?

Post by R0B »

Out of interest where did he put this filter?

He put in a transparent fuel filter over a year ago and there is no sign of dirt in it.
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kevtherev
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Re: Loss of power and misfiring MAF?

Post by kevtherev »


I am no mechanic but is there any advice that I can pass on to my mechanic?
Yes tell this "mechanic" thanks and goodbye. :D
Poor acceleration has to be investigated methodically.
Using the scatter parts method is just silly.

Start by getting a competant person to do all the easy and cheap stuff first.
Make sure all the vacuum hoses are in place and don't leak air
Make sure all the vacuum operated ancilliaries do not leak air (choke pull down test, second throttle test, distributor diaphagm, brake servo hose, gaskets etc
Once you're sure all these are ok move on to the carb.
You don't need to replace it, it just needs cleaning inside and maybe a few new seals and gaskets.
AGG 2.0L 8V. (Golf GTi MkIII)

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