Engine: 70 T5: - '98 V70 T5 occasionally cuts uut when not under load. - Page 3

CNGBiFuel · Sep 30th, 2021, 08:14

Quote:

Originally Posted by Distendo

Update and clue:

I've observed that it rarely stutters or cuts out when started and driven from cold.

However, if restarted when warm (or hot-ish), it may stall within the first few minutes.

Any ideas welcomed!

Also had (leaking!) fuel filter replaced. Possible slight improvement. Serious improvement to mpg...

Are you saying, this isn't cured?

Quote:

CHRA,

Quote:

ICV,

OK I used the acronym FPR, only this was in the next sentence, after I'd previosly referenced 'Fuel pump relay' These? I've googed, sorry NI. (No idea). Anyone?

acshortt5 · Sep 30th, 2021, 09:49

Normally:

CHRA = Compressor Housing Rotating Assembly (the main core bit of the turbo).

ICV = Idle Control Valve (On cable throttle cars anyway - the Electronic Throttle Module on the later cars takes care of this function so no need for a separate unit).

Having said that people frequently make up their own interpretations, for example I take FPR to normally mean Fuel Pressure Regulator although if you've used it next to the full meaning then that is fine for me.

One of the first things I was taught on my Uni course was that there are a lot of acronyms out there so you should always start off with the full spelling with the acronym in brackets after. Then for the rest of the essay/report you can just use the acronym.

CNGBiFuel · Oct 2nd, 2021, 17:28

Ah, makes more sense. Acronyms works well, provided your reader has a grip on them. I get the idea this fault hasn't been isolated, and seeing as I've got to look at a P80 with, what sounds like the same fault, I watch with interest.

Distendo · Nov 23rd, 2022, 15:05

So a week or so ago, wouldn't start. Engine turned but no go. Drove it previous day no problem (apart from the root issue for this thread).

AA comes out, fuel squirts from fuel rail thingy when depressed, no spark.

Relay truck to my Volvo indie. Immediate diagnosis without even looking: cam position sensor.

Cam sensor fault showed on obd readout. Sensor replaced, car started immediately.

Have driven it a few miles since, engine runs smoother (subtle diff. but I'm pretty sure of that), and the stalling seems resolved.

So I reckon it was the cam position sensor playing up until it gave up.

Interesting that xco had a similar issue caused by the crankshaft position sensor (see https://www.volvoforums.org.uk/showthread.php?t=324479).

If I get a return of the issue, I'll post here.

Distendo · Jul 14th, 2023, 18:24

MAF sensor.

Turns out the symptoms (stalling etc.) are 'classic' Mass Air Flow sensor symptoms.

Replaced it, problem now seems to actually be gone.

Sep 30th, 2021, 09:49	#22
acshortt5 Volvo Nutcase Last Online: Jul 14th, 2023 12:57 Join Date: May 2007 Location: N/A View Photos By: acshortt5	Normally: CHRA = Compressor Housing Rotating Assembly (the main core bit of the turbo). ICV = Idle Control Valve (On cable throttle cars anyway - the Electronic Throttle Module on the later cars takes care of this function so no need for a separate unit). Having said that people frequently make up their own interpretations, for example I take FPR to normally mean Fuel Pressure Regulator although if you've used it next to the full meaning then that is fine for me. One of the first things I was taught on my Uni course was that there are a lot of acronyms out there so you should always start off with the full spelling with the acronym in brackets after. Then for the rest of the essay/report you can just use the acronym. __________________ Andrew 1998 S70 T5 CD AUTO Previously a 1990 240 GLT-R Last edited by acshortt5; Sep 30th, 2021 at 10:12.

Oct 2nd, 2021, 17:28	#23
CNGBiFuel Classic P80 1999 BiFuel Last Online: Mar 6th, 2024 00:34 Join Date: Aug 2012 Location: 48mph Middle Lane M4	Ah, makes more sense. Acronyms works well, provided your reader has a grip on them. I get the idea this fault hasn't been isolated, and seeing as I've got to look at a P80 with, what sounds like the same fault, I watch with interest. __________________ Bifuel V70 Classic 1999 [The Old Grumpy in the Corner, "When I was a lad... blah, bl**dy blah."]

Nov 23rd, 2022, 15:05	#24
Distendo Member Last Online: Sep 17th, 2023 23:56 Join Date: Mar 2009 Location: Birmingham	Sorted! (? don't want to jinx it) So a week or so ago, wouldn't start. Engine turned but no go. Drove it previous day no problem (apart from the root issue for this thread). AA comes out, fuel squirts from fuel rail thingy when depressed, no spark. Relay truck to my Volvo indie. Immediate diagnosis without even looking: cam position sensor. Cam sensor fault showed on obd readout. Sensor replaced, car started immediately. Have driven it a few miles since, engine runs smoother (subtle diff. but I'm pretty sure of that), and the stalling seems resolved. So I reckon it was the cam position sensor playing up until it gave up. Interesting that xco had a similar issue caused by the crankshaft position sensor (see https://www.volvoforums.org.uk/showthread.php?t=324479). If I get a return of the issue, I'll post here. __________________ 1998 V70 T5, B5234T3

Jul 14th, 2023, 18:24	#25
Distendo Member Last Online: Sep 17th, 2023 23:56 Join Date: Mar 2009 Location: Birmingham	Cure MAF sensor. Turns out the symptoms (stalling etc.) are 'classic' Mass Air Flow sensor symptoms. Replaced it, problem now seems to actually be gone. __________________ 1998 V70 T5, B5234T3

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