87 240 B230F power loss glowing red manifold

Retired MVS Contributor · Post by **Retired MVS Contributor** » 24 Dec 2010, 06:50

The knock sensor sounds like a better guess than the cat...It is located just behind the distributor under the intake manifold...Late ignition timing will produce overheating and the job of the knock sensor is to retard the spark if detonation is occuring...Low octane fuel can cause it...

If the sensor is bad, it can throw an OBD fault...Have the fault codes been checked?...

Jerry

Retired MVS Contributor · Post by **Retired MVS Contributor** » 24 Dec 2010, 06:53

Sorry, my bad...The 240 did not have OBD in 1987...

Jerry

overgreg · Post by **overgreg** » 24 Dec 2010, 07:50

Thanks Jerry,

A quick inquiry with my wife and she says she uses Regular fuel(85 octane here) seldomly, but almost always mid grade (87 octane here). Is 87 too low for this car? The only higher octane in this area is Premium at 89 octane.

Also, should I replace the knock sensor or will switching to higher octane correct the issue? Is the sensor fubar or just being duped by the low octane fuel?

Greg

overgreg · Post by **overgreg** » 24 Dec 2010, 09:29

So, here we go. Another odd thing,; this car does not have a knock sensor. There's a plug in the block at that location and one red wire with female connector lying free below there. I saw photos of knock sensors online and they were black flat-ish things that used a Bosch square connector with spring wire clip, like the fuel injectors use.

Does the 87 b230f non-turbo engine use a big round knock sensor with a simple spade type plug?

This is strange. the car has run flawlessly for a long time, years, just like this. I know its previous owners, elderly, and it did not give them regular trouble. But since I am going to have to install a cat for emissions now, I'm going to go ahead and install the correct knock sensor - if I can find it, and cross my fingers that all this power loss business will go away with that.

Next question: the guy at the local shop says he 'thinks' my 87 uses two o2 sensors. I have one up by the manifold now. He says he's pretty sure it also uses one in the cat itself. Of course, that cat is more expensive, and then add the cost of another o2 sensor, and it pretty much sums up my week.

Hep me!

G

lummert · Post by **lummert** » 24 Dec 2010, 11:16

The part number for the knock sensor is 1317296 and is used on 83-88 Volvo 240 with B23F/B230F and has one male spade connector. Also there should only be one O2 sensor, up near the exhaust manifold.

overgreg · Post by **overgreg** » 24 Dec 2010, 12:05

Thanks lummert! Very helpful and appreciated. I'm off to search for that part #.

G

lummert · Post by **lummert** » 24 Dec 2010, 12:24

FCP Groton is one of the sponsors of this site. If you can wait for the part to be shipped the part will be less expensive than getting it locally.

overgreg · Post by **overgreg** » 24 Dec 2010, 12:42

Thanks. That's the first place I looked! Always great service from those guys, for Volvo. VW Eurovan and Saab. I got em all...

After seeing the photo of the knock sensor, it almost looks like the 'plug' in my block is the sensor with the head/spade plug broken off or removed. Maybe it fell off recently and that explains the problem cropping up now. The female plug on the wire does not have the spade still in it, so maybe it was removed on purpose or something, maybe it didn't fit tightly and came out when the top of the sensor fell off. Who knows?
I think we may have an explanation and a solution to my problem here, though.

Thanks to all! I'll get that baby ordered, installed, and then report back after a bunch of trouble free miles.

G

Retired MVS Contributor · Post by **Retired MVS Contributor** » 25 Dec 2010, 06:33

One ox sensor in the exhaust "down pipe" near the firewall, right side...

Post by **jimmy57** » 11 Jan 2011, 08:14

Is it fixed?

87 240 B230F power loss glowing red manifold

Re: 87 240 B230F power loss glowing red manifold