Baileyswhite
Member
- Joined
- Jan 8, 2012
- Location
- East Bay, CA, USA
I’ve got an ‘83 244 Turbo running LH2.2/breakerless. When I first bought it I had a very similar rhythmic surging at idle. I ended up doing a few things before I got it to smooth out, and to be entirely honest it still surges ever so slightly now, all tuned up.
(in no particular order)
-Make sure timing is dead on, 12 degrees (within two degrees of 12 for emissions)
-Make sure vacuum advance/boost retard distributor is working correctly, without any check valves or anything in the vacuum line between the manifold and the distributor. (Previous owner installed one-way check valve on this line on my car unbeknownst to me, causing the distributor to hold full advance always, resulting in detonation in boost)
-Make sure your fuel injectors are matched with your ECU/MAF combo. If the injectors you’re using are stock (for the ECU anyway)—you’re good. If you’re running bigger, higher flowing injectors you’ll need to add the appropriate sized resistor to the MAF>ECU signal wire to match your injectors so your ECU can function properly (remember—LH2.2 doesn’t do long term fuel trim, bigger injectors are outside of LH2.2’s adjusting ability). I don’t remember the threads I used to gather the info, but it is all on here. Check for threads about upgrading injectors on LH2.2.
-Make sure you have ZERO vacuum leaks. I’ve consistently had issues with my K-Jet injector plugs leaking (can’t source o-ring with strange dimesnsions of plug?). I ended up using an “okay” o-ring with a big gob of silicone all around. This has been the most effective method yet in sealing the old injector holes.
From there, set your timing, idle speed and base mixture by the Volvo procedure (a procedure very well documented on the 700/900 faq website, Google it). You’ll need a short jumper wire to set the idle correctly. Monitoring your O2 Sensor voltage during this will be helpful.
Mine ended up passing smog cleaner than any of my other Volvos, so it can be fixed.
Here’s mine: https://i.imgur.com/wAKrTZx.jpg
(in no particular order)
-Make sure timing is dead on, 12 degrees (within two degrees of 12 for emissions)
-Make sure vacuum advance/boost retard distributor is working correctly, without any check valves or anything in the vacuum line between the manifold and the distributor. (Previous owner installed one-way check valve on this line on my car unbeknownst to me, causing the distributor to hold full advance always, resulting in detonation in boost)
-Make sure your fuel injectors are matched with your ECU/MAF combo. If the injectors you’re using are stock (for the ECU anyway)—you’re good. If you’re running bigger, higher flowing injectors you’ll need to add the appropriate sized resistor to the MAF>ECU signal wire to match your injectors so your ECU can function properly (remember—LH2.2 doesn’t do long term fuel trim, bigger injectors are outside of LH2.2’s adjusting ability). I don’t remember the threads I used to gather the info, but it is all on here. Check for threads about upgrading injectors on LH2.2.
-Make sure you have ZERO vacuum leaks. I’ve consistently had issues with my K-Jet injector plugs leaking (can’t source o-ring with strange dimesnsions of plug?). I ended up using an “okay” o-ring with a big gob of silicone all around. This has been the most effective method yet in sealing the old injector holes.
From there, set your timing, idle speed and base mixture by the Volvo procedure (a procedure very well documented on the 700/900 faq website, Google it). You’ll need a short jumper wire to set the idle correctly. Monitoring your O2 Sensor voltage during this will be helpful.
Mine ended up passing smog cleaner than any of my other Volvos, so it can be fixed.
Here’s mine: https://i.imgur.com/wAKrTZx.jpg
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