Hi Everyone,

I have a 1992 Volvo 240 N/A, automatic, 270,000 miles. When I got this car over a year ago I noticed that there were times when the engine would stumble and shut off only during idle. Not while driving. I am given code 232 on fuel codes and I believe 214 or 241 (I have to double check) on the ignition codes. I have done a ton of research and I have learned this could be a tricky issue to fix. It could range anywhere from a fuel issue, to an ignition issue, to a vacuum issue, to an electrical issue and so on. For a while I thought it was possibly my O2 sensor and did some research and found a lot of people say that even if an O2 was that bad it still wouldn't cause issues such as engine stumble and shut off during idle. I ran across some recent research and I have found a few new suspects. I found that a bad or leaking fuel pressure regulator could cause my issue. It looks original on my vehicle and I have never checked it out before. I was told to pull the hose off of the regulator and smell it and if it smells like fuel then I need to replace the regulator because its leaking. I did that today and it does smell like fuel. Another suspect I found was the air control valve. I was told that a bad one could cause your air levels in the car to be off and cause poor performance. I do have loss of power during acceleration until I reach about 40ish mph and up. I feel an increase in power around that mph area. I have only taken the air control valve off once mistaking it for my EGR valve and when I did check it all the connectors and what not seemed in good condition. Although it could just not be working at all. This checking of the air control valve was a little over a year ago a few months after I first got the car. People also keep telling me check spark plugs, distributor, and all that stuff. But I have done much more than that within the last year. A year ago I got all new plugs and wires, distributor and rotor. A new fuel filter and relay. I did a head gasket job about 4 months ago. All vacuum lines looked decent. Nothing looked bad enough to the extent that it would cause serious issues. All my fuel injectors got soaked in carb cleaner and got refitted with all new bushings, etc. I also found some research stating that a bad harmonic balancer could cause idle issues and shut offs. I hear some squealing going on in my engine sometimes and its probably the cheap harmonic balancer I installed at the end of my head gasket job. I did notice that my idle was still a little rough but I had NO shut offs after I did the head gasket job. The shut offs seem to be getting progressively worse over time. So I don't know if that means something has been wearing over the course of however much time and now its just shot or its just something else. I have also further researched and found that some sensors can cause rough idle and shut off. Well anyway, I feel I have covered alot already and that I should be getting close to my problem. It cant be anything electrical because electrically my car is fine. All grounds look clean. It cant be an ignition issue because my ignition is just fine. My injectors, throttle body, intake manifold, etc. were all thoroughly cleaned during head gasket job as well as a brand new intake gasket. So I feel it has really come down to my fuel pressure regulator or air control valve. Oh, and I also tried the MAF trick of unplugging it and it didn't change the cars performance. It made it worse actually. But my MAF looks a little beat up so I am sure a nice used one from the junkyard would help over all. Anyway, let me know what you guys think.

Peace.

 

I also forgot to mention that it does fine in park but once I put it in drive and just hold the brake and let it idle in drive is shuts off and stumbles then. It rarely does it when I am in park but when I am idling in drive. Its my understanding compression and pressures change when you go from park to drive so that may be able to help pinpoint the issue.

Thanks Again.

 

a 1992 has LH2.4, which means it has the diagnostic panel, which not only reads out fault codes, but can initiate some 'tests'. DTM #3 (diagnostic test mode #3) cycles a bunch of actuators, including the idle air controller.
see here: Engine and OBD Diagnostic Codes

I think I would disconnect one of the hoses from the idle air controller, hook up a length of clear hose, and blow through it while runnign that test, if its working properly, you'll feel your breath getting chopped on/off/on/off during the IAC portion of the test.


as far as your diag codes... clear them, and verify they come back consistently before you try and fix things.

2-3-2, I show as 'lambda too lean or rich at idle'. lean could be caused by air leaks, low fuel pressure, bad o2 sensor. too rich could be caused by high fuel pressure, leaky injector. since you're ONLY seeing the idle fault and not the 'part load' fault 2-3-1, I'd be looking at things that only affect idle.

2-4-1 is a EGR code. does this car have an EGR ? (thats a California thing mostly). EGR problems can definitely cause stalling.

the 'ignition' side of DTM #3 cycles the EGR valve actuator. to see if the EGR itself is working, unplug the vacuum hose and use a mity-vac while the car is idling, if you suck on the hose, the car should stall.

 

Yea it does have an EGR valve. After I finished my head gasket job I was unable to put the EGR metal hose back on because the bung nut threads had stripped and it wont attach properly to the EGR so I have left it undone. i was told it wouldn't effect it to much. And like I said the car had been doing this before I did the head gasket and even when I got it. I also understand the codes and am now in a position that I want to start weeding out options. My next step is to check the Idle control valve, the fuel pressure regulator, and the EGR valve now. I may pick them up from the junkyard and put them on and see how the car runs. I will also run diagnostics on 3. I have used my diagnostics before but was unsure if 3 could be used. I only seen metal connectors for checking on 2 and 6.

 

OK, so based upon what I have read from your attachment. My issues could simply be my oxygen sensor and my EGR valve. Because its giving me the codes. I guess instead of just ignoring the codes and going by pure capable instinct I could just fix what the codes are telling me and see if the car will be fine after that? LOL. Seems possible and simple. I guess like most other do yourself people I have just some how picked up the behavior of not trusting specific codes identifying a specific problem since so many systems are interconnected and one issue could be replicated by several different components. I will take care of these first and see what happens.

Peace

 

If my code from socket 6 is saying 214 when I check it then its saying its an RPM sensor which if bad could cause the engine to run rough. So maybe I need to look into this. From what I have researched it apparently sits on top of the transmission on the back of the firewall. Will I need to drop the tranny to check it out? Thanks again.

Peace

 

the pipe you left off is the one that connects the exhaust to the EGR valve under the intake manifold?

I'd sort that out, I think, before worrying about the O2 sensor. did you also unplug the EGR actuator (thats the tophat looking thing on the left fender with two vacuum lines)? I think I'd try that, with that unplugged, the EGR valve won't open... as it is, when the valve opens, its getting air rather than inert exhaust gas, this could be throwing things for a loop.

 

the RPM sensor is commnoly called the crank position sensor or CPS. its behind the head, on top of the bell housing, on the intake side of things, should be accessible without removing anything, although its tight back there. often its the wire rather than the sensor

 

Yea I seen the CPS information and I will look into it if this EGR doesnt do the trick. I know the EGR actuator you are talking about. Whats the process of checking this for the EGR valve? I didn't fully understand your previous post. And yes this EGR hard line is connected to the back of the exhaust manifold to the back of the EGR valve. I just couldnt get the threads to catch on the EGR valve. I will hit the junkyard and pull an EGR valve off with the hardline and see if I can put it on mine and see how that does. If I find the EGR valve is faulty. I have had this EGR code for a long time. I cleaned the EGR and what not but its probably just old and needing replacing.

 

ok, the egr systems works like this... the ICU (ignition controller) sends EGR pulses to that 'top hat' EGR vacuum control on the left fender. this allows vacuum to hit the EGR actuator, which opens the EGR valve itself, allowing exhaust gasses into the intake manifold when the car doesn't need gas....

there's a DTM#3 test mode on LH2.4 cars that exercises the various engine actuators. with the diagnostic block plugged into the 'ignition' port (socket 6), this tests the EGR by pulsing it on/off/on/off. so the first test is, disconnect the vacuum hose from the EGR controller, and hook up a clean hose, blow gently on the end of this hose while DTM#3 is running, and you should feel the air being 'chopped' on/off/on/off at about 1 second intervals. if you get that, then the ICU and vacuum control are working fine.

the next test is to disconnect the vacuum line that goes from that controller to the vacuum actuator under the intake manifold, and plug the line into a Mity-vac or similar suction device. start the car, get it idling, and suck on the Mity-vac, the engine should stumble, and stall if you suck enough. if that happens, the whole EGR system should be good to go.

I suspect its OK to run without that EGR pipe *IF* you plug up both ends. you'll probably get EGR fault codes, which means your car won't pass smog inspection, but it should run OK.

oh, re: DTM #3, see Engine and OBD Diagnostic Codes

 

Ok I will look into that when I can. Could be a while, still working on some other things. Thanks Again.