I am working on a 91 model 240. The back story on the car is it sat at a shop for about two years and the mech said he coulld not figure out what was wrong.

I got the car from the owner who was tired of it sitting at the shop. The fuel ECM was not sending a sinal to ground the fuel pump relay or fire the injectors. I replaced the fuel ECM and the car started and ran. All the fuel was drained, new filters, new plugs, wires, cap, roter, belts etc....all the stuff you would expect for one that has been sitting so long.

Car runs great at idle but will not accelerate. If you unplug mass air meter it runs good (will accelerate fine) but stumbles at idle. Check Eng lite is on the IGN shows no codes. FUEL syst shows code 411 which does not show up in mitchell.

I have replaced the MASS AIR METER and throttle position switch. With mass air meter pluged in it will take more throttle if you hold your hand over the MASS AIR METER opening to close off some air.

I am at my wits end with this thing. any ideas ??????

 

I've seen a car with the wrong mass air meter plugged in. They run poorly. if unplugging it makes sun better, maybe that could be it. If you've checked the part number, then you probably have it right, unless is was already the wrong part and someone before put in the wrong thing.

Your car, being a 91, should have no cylindrical thing next to the plug where the mass air flow sensor plugs into the wire harness. Look a the picture. It's my car's. It has an older style MAF sensor and is not compatible. Your year of car should have one without that round thing next to the plug. I'm not sure if that's it, but it's a quick and easy start.

 

Thanks for the reply but that is not the case. Both the new and old Mass Air Meter do not have the cyl part next to the plug. If the darn thing would idle better with MAM unplugged I would just say to heck with it and let it go.

Any other Ideas. I am a pretty good mech on americian cars but I am learnig as I go on this eroupean stuff. I cant afford to keep throwing parts at it. I need to get it fixed.

 

411 is " Throttle position sensor signal absent or faulty LH 3.1". Is this a 3.1 a 2.4, automatic or stick.

RonJ

 

The Engine is a B230F with Automatic

 

What is the last three numbers of the Bosch part number on the AMM? It would also be a good idea to measure the output of the O2 sensor (with everything connected during warm idle). Follow the wires from the sensor, the output connects to a thick green wire. You can probe it by peeling back the rubber boot on the connector. A properly functioning sensor will have a quick voltage swing between .2 and .8 VDC.

 

Does the throttle switch click when it's just barely opened.

RonJ

 

Ron J,

Thans for the replies. Yes the switch clicks.

Mitchell tells me the from ECU terminal number 2 (Wht/yel) to ground switch should show 0 ohms. Press acc pedal slightly and should show 2000 to 3000 ohms.

It reads 0 ohms throttle closed and open when pedel depressed slightly.

On ECU term no 3 to ground it should read infinate(open) with thrott closed and 0 0hms at WOT (wide open thrott).

It reads correctly.

Oreilly shows two diff thrott pos switches for this car. Maybe I have the wrong one. Both look identical in pics.

Could the one I have reading open instead of 2000 to 3000 ohms be the whole prob.

Mitchell did not even list code 411 on thier code chart so I am starting to wonder how much to rely on them.

I dont have the orginal Thrott switch anymore but it did not ohm out correctly per mitchell.

 

Do you know if your car is LH2.4 or LH3.1. What are the part number on the AMM and your TPS. Is this a US spec. car. Also, I have never heard of this Mitchell Manual you are referring to. The manuals we most refer to are the Hayne's, The Bentley Bible, or the official Volvo green manual.

RonJ

 

Ron,

I believe it is a LH 2.4 system but I am not certain. The bosch pn on the old MAM (AMM?) Mass Air Meter is 0280212016. I no longer have the original TPS so I do not know what the pn was. The replacement is a BWD brand pn EC1084 it replaces Bosch pn 280120325.

The other option I have is for TPS is BWD pn EC3040 replaces BOSCH pn 280122001

Mitchell is annother brand of auto repair info like ALL DATA or CHILTON. I subscibe to them online for repair data. The have been around for a good while.

Is there a quick easy way to determine the system I have. Looking at wire diagrams and such on mithcell it looks to be the 2.4?

Sean

 

The -016 AMM is for a LH2.4 car, and the -325 is the correct TPS (according to FCPgroton's website).

 

Bubba is correct. Those are the correct part numbers for a LH 2.4. The problem is at the beginning if this thread you gave us a code, 411, that is for a defective AMM ( Air Mass Meter ) for a LH 3.1. So the question still remains, is it a LH 2.4 or LH 3.1. Since you can't give us a definitive answer I would suggest you take your chassis number to a Volvo dealer an see if they can tell you what system you have or at least what it was when it left the factory.

RonJ

 

Or maybe check the codes again, maybe you mis-counted the flashes?

 

I have already changed the fuel ECM with a used one. Is it possibe I have a 2.4 sys and installed a 3.1 ECU? Are the elec connetors the same?

 

That thought has crossed my mind but I'm not familiar with the connection differences between 2.4 and 3.1. If you could send us your Chassis number (YV1AA etc.) maybe we can determine what it's suppose to be.

RonJ

 

YV1AA8849M1453647 is the VIN

The new (used) ECU is Bosch 0 280 000 572 dont have the old one anymore (just tossed it last week).

 

http://www.nuceng.ca/bill/volvo/database/ecu.htm

So that is the problem - you have a LH3.1 ECU and a LH2.4 air mass meter. My *guess* is you have LH2.4 car since your AMM wire harness connector matches up to the -016 AMM.

 

So that's why your getting a 411 code. Bubba's right wrong ECU. You may have some options here but 0 280 000 556 would be the original ECU. Also 951 and 946 may also work.

RonJ

 

So should I find a new computer or change TPS and AMM to match 3.1 syst?

 

You'll want to find a LH2.4 ECU, thats what your car is wired for.