Hi,folks

My wife own a 91'740tic. with 80k (and we really luv it). We haven't had any problems for the last 2 years and suddenly the car had a weird problem (at least for me)
The symptoms,
start fine and after warm up (10 min or so) it start to cough and then the engine stop. I re start the engine and it run well for a couple of minutes and then the rpm goes down,coughing and stop. I put a load on the throtle it run ok (rpm >1000) but when ever i release the load it start to cough,rpm goes down and then the engine stop. The obd gave 1-1-3, 2-3-2 code.
With the assistance of a volvo mechanic (friend of mine)we did the following :
-Clean TB, IAC, adjust the TPS
-Check vacum hoses (it seems noleak except the hoses from airbox (after the AMM)to turbo)
-Replace the injector relay (i bought a bosch relay )
-Check the fuel pump relay (its ok), O2 sensor (its bad, didn't replace), AMM is good

After we did the above, the car run OK but the iddle still rough (400 - 750)and the OBD gave 2-3-2 code. We are going to replace the hoses and try to re-adjust the TPS.
Some other things that come across my mind are ; bad FPR, bad exhaust line, incorrect TPS adjustment, bad injector, dirty fuel line)
So please advise me of what i have to do to solve the problem.
I appreciate any opinion
Thanks

David

Ive had a somewhat rough idle throughout my ownership of a 780 ti (same engine). I recently replaced the rear main seal, and in doing so replaced the distributor. In doing so, I also removed the distributor and was forced to reset the timing and idle. My engine has been running much more smoothly lately, something which I attribute to my adjustment of the timing (I cant tell you the original timing spec because I didnt test it first). If you look at the procedure for setting timing in any manual, it also recommends adjusting idle at the same time, this allows you to sort of "hone" in on the ideal 12.5 deg BTC/750 rpm. Also, since I live in houston I set the idle while running the AC, since I really use it as a non-optional accessory.

It sounds like you you've done everything but the simplest one of all. For my '86 240DL, I bought a can of BG44k fuel system cleaner because of rough idle and high emissions output. A few threads on brickboard recommended this cleaner above all others for Volvos so I figured I'd give it a try. It really smoothed out my rough idle. I bought mine at a Goodyear/Gemini service center in Atlanta. Hard to find, but worth it! It doesnt sell retail so you gotta call around to auto centers. Dont waste your time with pepboys, Napa, or anything else like that, they wont have it.

Iforgot to mention that i've done it, I used redline fuel system cleaner. But thanks Barry for your suggestion i do appreciate. i'm going to try the BG44K this week if i can get the product. cause i live in Indonesia (remember Bali?)

Regards,

David

Dave,

Any solution yet to your problem? My 740 16V has been in the shop for four weeks. My mechanic (Volvo indy) cannot figure out why my engine runs rough and nearly stalls at low RMP (700-1000). At high RPM's the car runs like a champ......