1991 240DL Error Codes

OK, now I feel a little dumb by not reading further down the listings since you have pulled the codes.

I still recommend cleaning the grounds on the intake manifold and the switches and contacts from my other post. The ECU references those grounds as part of its self diagnostics as well as relying on them for component grounds. So if those grounds are bad, or the connections are bad, everything is screwed up.

I had the same set of codes when I bought my 90. The sellers dumped it after the mechanic they used put over $1400 worth of parts at it and still could not get the codes to clear. Had to sell since they could not renew registration.

I cleaned the grounds and have not seen them since. See rational below.

The ECU references engine signals based upon resistance and voltage flow. Voltage is affected by resistance. (Ohm's Law). So any extra resistance can really screw the system a lot.

Also since the ECU can only store 3 codes, any that were set before you checked may have been wiped out. Pull the codes with a minute after clearing them and restarting. You may end up with one or two which helps narrow down the search.

213 needs to be checked with a Ohm meter to be sure. It could be dirty and shorting to ground. Throttle switch is toward the firewall side of the furthest most left part of the intake manifold.

232 The Lambda system is compensating at idle for a mixture imbalance caused by

113 faulty injectors.

Is the mixture rich or lean? Pull a plug or two and see. Dark and wet, rich. White and dry, lean.

The injectors are pulsed by the ECU via the grounds on the intake manifold. IF the injectors are not grounded properly, also through the same grounds, the injector will not fire properly or at all.

Duane

I would advise against replacing things willy-nilly. It's quite possible that only one thing is wrong and that this has caused the others to trigger.

Hmmm. I think I would start with the crank position sensor- partly because it's inexpensive! However, I would also counsel waiting for wiser heads than mine to weigh in on the discussion.

If this gets the car running, then clear the codes and wait and see.

Duane - I did a test on the Fuel Pressure Regulator.and when I unlpug the thinner hose and start the car no gas comes out at all - When I unplug the thicker short hose, fuel streams steady and fast out of it so the fuel is not bypassing the FPR I think. I will replace it first tomorrow and go from there - I will also clean all the grounds and connectos to see if that helps also -

Is the ECU located in the car at the feet of the passengers

Duane - I did a test on the Fuel Pressure Regulator.and when I unlpug the thinner hose and start the car no gas comes out at all - When I unplug the thicker short hose, fuel streams steady and fast out of it so the fuel is not bypassing the FPR I think. I will replace it first tomorrow and go from there - I will also clean all the grounds and connectos to see if that helps also -

Is the ECU located in the car at the feet of the passengers

Check the O2 sensor output. Usually that cluster of codes means it's bad.

Bob

i also wanted to find out the answer for tat problem...if u could solve plz let me knw

regards free MMOG MOG

i also wanted to find out the answer for tat problem...if u could solve plz let me knw

regards free MMOG MOG

The O2 Sensor wouldnt cause the car to not start - it would just make it run terrible if it was bad

It appears the FPR is functioning and not leaking. Why replace it?? Replace it only if leaking, it does not maintain pressure, or it does not react to vacuum changes. The first is not happening and the other two require testing.

ECU needs to know engine temp and amount of air entering system to determine how long to pusle injectors to deliver a fuel-air mix that will ignite. Injectors have a fixed opening that will deliver a known volume of fuel at a given pressure. At idle, the ECU also adjusts air entering system via the air control valve based upon RPM info.

The system will not pump fuel if the RPM signal is missing, so any fuel flow while cranking indicates the RPM sensor is functioning.

O2 sensor comes online after about two minutes, sometimes longer, and is used only after the ECU stops compensating for a cold engine.

A no start condition or poor running within two minutes of startup is not caused by the O2 sensor unless the ECU is faulty. And most ECU's are bullet proof unless tested incorrectly.

A bad air or dirty air control valve can really screw with an engine. With a closed throttle plate the only way air can get to the engine is via that valve. If open poor running lean, if closed poor running rich.

I strongly recommend the purchase of a Bentley manual to assit in this diagnoses. An investment of $40 could save many times that in parts not needed and time wasted.

It has a section that guides the user through testing the ECU outputs to see if the varius critical components are reacting to output signals from the ECU.

Duane

From your following statement on the previous thread:

I am curious and completely ignorant when it comes to mechanical issues but would like to know what the RPM sensor is(does it go by another name), where it is and if I have one on a 94 940 turbo (B230FT).

The RPM sensor is a coil style pick up that is mounted on top of the bell housing just behind the head.

From early schooling, remember that electricity is generated by a magnet passing through a coil of wire. In this case the coil reacts to magnets placed around the flywheel which as they pass the coil, induce a brief but measurable voltage.

Two magnets close together at Top Dead Center are used as reference for the rest of the pulses. The computer knows where the crankshaft is depending upon how many and when the pulses occur. It can then fire the spark plugs at the best time for power, economy and emmmissions.

Yes, after 1986, all Volvos with the 230 engines had the sensor on the top of the bell housing instead of inside the distributor.

To prevent fuel from being pumped after a crash which stops the engine, the ECU grounds the relay coil that controls the fuel pumps only if the RPM signal is present. No RPM, no relay coil ground, no fuel pumping.

Duane

Thanks, that makes things a lot clearer

OK Duane - I really appreciate all your suggestions. I really do. I do not have cash to have this thing towed to a shop and to have them repair it. I will pay them to fine tune it once I get this f^%$#^#^ker running. Sorry, Im really frustrated. My car knowledge is about a 6 on a 1-10 scale with 5 being average so I understand and can try most theories and I have access to sevreral salvage yards. Heres where Im at..

I reconnected the hanging loose engine ground wire I found that had torn. Just a basic motor ground. I replaced the Fuel Pressure Regulator - I did drop the screw, heard it hit and bounce so currently there is no screw in it but it is steady and not moving anywhere but the car still dont start. Hopefully without the screw it doesnt matter, temporarily The car seemed to turn over a bit cleaner and more steady but will not fire up.

I have replaced the IAC, checked that the AMM is working, checked all hoses and connections. I do still have the original lose wire that I cannot figure out where it goes. It appears to be a EGR Temp Sensor plug but I cannot figure out where it plugs in. I dont think this would keep the car from starting and it may have been disconnected since I bought the car and I have driven approx. 100 on the car. Its the Sensor in the photo on the lower right ]

car went from running but running very rich to suddenly not runningat all. Fuel Pump Relay has been replaced. I am at a point where I amgoing to buy a ECU from the salvage yard to see if this is the problembut with the money I just spent on the FPR its getting where I need tofind this issue quick.