Hello everybody, I have a 1994 940 regina ignition. For some reason I encounter several problem on starting and accelerating. The whole car feels like it has no life left. First I have a rough starting in the morning and after it is parked for a few hours. second, as soon as I turn on the AC the engine is spattering and I have no throttle.. It has 233,221,122 codes. I replaced the fuel pump not long ago, idle valve(used from junk yard). I have a hollow catalytic converter. I'm kind of stuck. I run out of ideas. I will appreciate any kind of help. Thank you in advance.

 

Also, it has backfires when she does this.

 

2-3-3 is... idle valve closed. so your junkyard idle air controller is bad or not connected properly. that certainly will make for rough starting AND sputtering when you engage the A/C

2-2-1 says your O2 sensor isn't working.
1-2-2 says your intake air temp sensor is missing. EITHER of these last two put your car in limp-home mode. time to sort that out. I've never touched a Regina system, but they use intake air temp as a primary input to know how much fuel to inject, without it, you're in limp home mode.

time to sort this stuff out.

 

LH2.4 can only store 4 codes...so you have a full house. There is no way to determine if codes are old history codes or if they all occur routinely in the present. Clear all the codes and see what comes back. If you have no record of the O2 sensor having been changed, my personal opinion is to replace it...with a new one. A bad or lazy O2 sensor can mimic all sorts of issues. Some folks will say that's throwing parts at an issue but I feel that a properly operating O2 issue is so critical to proper engine performance that on my own cars, I seldom check 'em...I just put a new one in.

 

Thank you all for the inputs. Great. The car has 230000 miles. sometimes runs just fine for weeks, and all of a sudden start acting weird. the check engine light stays on for a full cycle and after that goes of for a period of time. I replaced two idle valves. same think. they are both bad?

 

Unfortunately a new idle valve runs 500$. kind of expensive.

 

You don't need to sweat replacing the IAC...it doesn't affect starting and certainly doesn't affect the driveability of the car. All it does is control the idle speed and keep it from dying at idle...especially convenient with automatics. Taking a long time to start after sitting all night or hours always makes me think fuel. A bad fuel check valve can increase starting time from a normal of 2-3 seconds to as much as 8. Longer than that makes me think engine coolant sensor....especially when you have a code for it Be advised that the wire connection at the sensor fails as often as the sensor itself. The wires become separated at the connector.
LH2.4 can have a host of issues that never trip the CEL. It will hold old codes in memory indefinitely until battery power is lost or it is reset. So...reset the code reader. I will say again, the O2 sensor is the most often overlooked, readily accessible, sensor on the car. Many people presume an O2 only is necessary for emissions...or possibly mileage The truth is, it is the lone sentinel that tells the fuel computer whether the engine is running appropriatley. It can be fooled sometimes. For instance, a leak at the exhaust mani will introduce air into the exhaust. The O2 will read that as a lean condition and tell the ecu. The ecu will then compensate and the engine will run rich. Then, unsuspecting owners start throwing amm's, injectors, plugs nd wires at the car in an effort to fix it. That's why I always replace the O2 on a new to me car unless I'm positive it is relatively new. It gives me a bench line to work from. Also, I've had old O2's read on the low side of acceptable and still contribute to running conditions.

 

this is a regina car, not bosch lh. the intake air temperature sensor is critical to regina operation, it will run like crap if thats not working. a bad o2 sensor will make it worse.

most temp sensors can be tested with an ohmeter, but I don't know the values for the regina (bosch doesn't even HAVE one, although it does have a coolant temp)

 

Sure...it's a Regina car...my bad. ALL 94 n/a's in the US were Regina. Turbo cars were Bosch of course. What effect a failed ecs has on engine operation depends upon what temp value it fails. After all, its resistance values dictate the fuel enrichment performed by the ecu. I've seen ecs's fail all along the spectrum. They can fail and only effect only cold starts and run fine when warm. Regina and LH2.4 will learn around the running condition eventually if the O2 is on point.
Pierce, I must have misread your post; I'm sure you know LH systems have used an ecs since at least 1981.

 

yeah, i worded that badly.