1993 850 RPM pulsing up and down at idle Topic is solved

VolvoMis · Post by **VolvoMis** » 26 Oct 2017, 01:16

Check your exhaust manifold and o2 sensor if you have one.

Paul-93-850 · Post by **Paul-93-850** » 26 Oct 2017, 13:32

"Check your exhaust manifold and o2 sensor if you have one" is a rather vague suggestion.

Post by **bmdubya1198** » 26 Oct 2017, 15:13

I believe he meant check your exhaust manifold for cracks (which you'd probably hear). As for the O2 sensors, I don't know how to go about checking those on a non-OBD2 car. That's something you would have to do some research on.

Paul-93-850 · Post by **Paul-93-850** » 30 Oct 2017, 01:35

bmdubya1198 wrote: ↑26 Oct 2017, 15:13 I believe he meant check your exhaust manifold for cracks (which you'd probably hear). As for the O2 sensors, I don't know how to go about checking those on a non-OBD2 car. That's something you would have to do some research on.

Posting on forums is research. Hoping that a Volvo genius reads this and has something specific. I really don't have the money to buy part after part hoping to get lucky.

Post by **wizechatmgr** » 30 Oct 2017, 02:20

No one suggested you just replace parts. Testing and verifying a part is defective when possible is key. Here's a great link:
http://lmgtfy.com/?q=How+to+test+oxygen+sensors

Post by **bmdubya1198** » 30 Oct 2017, 09:02

wizechatmgr wrote: ↑30 Oct 2017, 02:20 No one suggested you just replace parts. Testing and verifying a part is defective when possible is key. Here's a great link:
http://lmgtfy.com/?q=How+to+test+oxygen+sensors

Exactly. We can't do everything for you. We're here to help, but it's not up to us to spend time reposting things that are already fairly easily accessible.

Paul-93-850 · Post by **Paul-93-850** » 19 Jun 2018, 18:27

The entire problem was vacuum leaks. Nothing to do with the MAF or re-manufactured MAF.

I replaced the rubber ends on the small vacuum hoses using pieces from a roll of 5/32 vacuum tubing that I had sitting around. I replaced the intake manifold gasket, the PCV hoses, the vacuum tree, the brake booster hose etc. Removing the intake manifold and the EGR was not easy or pleasant.

Post by **bmdubya1198** » 20 Jun 2018, 08:19

The intake manifold is much more of a pain than you would think on these cars. Glad you got it taken care of!

Post by **erikv11** » 20 Jun 2018, 18:12

Smart move replacing all of the 20+ year old vacuum lines. And thanks for telling us what fixed it!

Post by **abscate** » 22 Jun 2018, 02:42

bmdubya1198 wrote: ↑20 Jun 2018, 08:19 The intake manifold is much more of a pain than you would think on these cars. Glad you got it taken care of!

It’s a “ right tool selection” job

With a 1/4 inch ratchet, wobbles, and a collection of extensions it’s quite a snap. Add in a magnetic pickup and some grease to stick bolts into sockets and it’s practically a cake walk. Ok, maybe a cake jog.

1993 850 RPM pulsing up and down at idle Topic is solved

Re: 1993 850 RPM pulsing up and down at idle