Maron, for future referance.

Imageshack.us and Photobucket.com host images. So you don't have ot email them and you can post them up (unless you just wanted to email Tech of course).

 

Does the idle speed hunt only with the shifter in "P"?


JPN

 

RedTurbo thanks for that suggestion. JPN, that time it happens when I shift it on "P". It ussualy happen when car stop on stop light or on "P" or driving. At first I was thingking that it was just bad connection. I had MAP sensor replaced already patch the hole on intake hose put some transmission fluid, still having the problem.

Maroon
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Good evening Maroon,

I just went over all replies on this thread and would like to knowa fewthings, if you could provide us:

1. Does your 850 have maintenance record? Do you have some ideas as to when the last tune-up was done?

2. The ECU seems like it's having a difficult time determining what RPM to keep, could be having a faulty signal input from a sensor. Is CEL back on again? I recently worked on a Ford F-350, whichhad an identical problem. In this case, the culprit was the faulty TPS (Throttle Position Sensor).

3. If nothing else solves the problem, try making the ECU re-learn idle speed. Here's what I do:

a. Disconnect negative battery cable.
b. Wait 15 minutes, and remove the 2 ECU modules from their nests, being careful not to touch the metal connectors with hands, as static discharge can damage internal components.
c. Blow out both male & female connectors with a can of air duster. I used WD-40 too, but if you do this you must make sure that you completely blowWD-40out in the end.
d. Reinstall the ECUs.
e. Re-connect the negative battery cable. Make sure both positive & negative connections are clean.
f. Turn off ALL electrical components, disengage parking brake.
g. Start the engine without stepping on the brakes. Do not turn on any electrical component.
h. Let the engine idle for 10 minutes. During this 10-minute period, you must not turn on any electrical component, not even parking lights. The engine must re-learn idle with no electrical load.

If this still does not solve the problem, give us a last reply and if no one could come up with a solution, be prepared to make a donation to the nearest Volvo dealer.

I hope this helps.


JPN

 

The black tape might have shrunk like shrink rap and opened the hole again.(Seen it many times).
Any engine light yet?

 

Good morning guys!! Thanks for the reply. Tech, the patch is still intact and yes CEL comes on. I will try JPN's suggestion ....one thing I want to make sure is the 2 ECU what it is and exact location on 1996 volvo 850 non turbo...I'll wait for your reply JPN. again, thanks!!

JPN, another thing I would like to do is tune up, I believe it was last tune up five years ago but I just put about 25,000 miles in five years. Can you give me suggestion on what do I have to replaced (wirings, spark plugs etc.etc)
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The 2 ECU's he is refering to is the 2 computers in the black box behind the washer fluid fill pipe. One is the engine module and the other is the transmission module.
Once the cover is off the box you will slide the handle on the computer to the opposite side then lift up to remove the computer.

 

Thanks Tech, I think I have to tune up first before doing that....just want to make sure what else I need to replace except for spark plugs etc. so I can go to autozone and get the items needed.
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Look at the plug wires if they are OEM wires they have the date stamped on them.
If they are over 5 years old replace them and the dist. cap and rotor.

 

Hello Maroon,

This is the post that should help many 850 drivers:

https://volvoforums.com/m_48928/tm.htm

I'll also copy & paste tune-up items:

---COPY---

ROUTINE TUNE-UP ITEMS:

1. Spark Plugs (Genuine Volvo or Bosch Platinum is a good choice, I use Bosch Platinum).
2. Plug Wires (French Bougicord is the OEM, Bosch makes them as well but I went with the OEM).
3. Distributor Cap & Rotor (Bosch is the OEM).
4. Air Filter (MANN is the OEM).
5. Fuel Filter (Bosch is the OEM).
6. Serpentine Accessory Drive Belt (Continental Tech is the OEM). Longer belt is recommended.
7. Tyre Rotation (watch out for the rotation direction arrow on the sidewall).
8. Exterior/Interior Light Bulbs.
9. Checking for Transmission Fluid Level.
10. Checking for Power Steering Fluid Level.
11. Checking for Brake Fluid Level.
12. Checking for Coolant Level (must not be at MAX mark when cold, it has to be about the middle between MAX & MIN). Should you decide to replace coolant, use high-quality coolant and avoid cheap/generic brands. I use Prestone, as Volvo genuine coolant was $20/gallon.
13. Checking for the Condition of Battery (Do multimeter test & S.G test).

---END OF COPY---

As for parts, I personally wouldn't buy them from AutoZone, except for Bosch Platinum +2 or +4 plugs. Especially in Volvo, you get what you pay for. Try to go with OEM if you can. I use FCP Groton of Connecticut as the primary parts source:

http://www.fcpgroton.com/volvo850tuneup.htm

If you're going to have it done at a shop, make sure that they accept parts from customers, as some places don't.

Also, for non-turbo models, you may want to do some replacement or cleaning on the PCV system, my 850 was turbocharged, and it had different PCV system so I couldn't help you with your system.

I hope this helps.


JPN

 

Thanks, That was good information about tune up. I'll do that on my next day off and keep you all updated on what's going on. Glad to know about this web site and people that help/share thier knowledge. If I can help on anything let me know.....more power!!!
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JPN, I had a chance to do the instruction about trying ECU to re learn idle speed since the car tune up is not due yet. I followed the instruction that you gave me, when I reach in, to turn the engine on the alarm went off, all lights were on....anyway I turn the alarm off then turn the engine on, it was running good for about 3 minutes then the RPM starts going up and down again then the engine stop running. I turn it on again RPM was the same going up and down for about 3 minutes then settle down. After about 13 minutes I drove around the block several times then park it infront of the house, I change gear over and over ...RPM settle down, so I think it's something good. I will observe the car and let you know. Thanks so much!!

Maroon
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Hi Maroon,

I too, was helped by many, so I try to post thorough replies in return, for others' benefit. I believe this is the American Way.

Anyway, the idle problem was probably electrical/electronic system-related, rather than mechanical (except for dirty throttle body that needed good cleaning). Volvos are extremely sensitive to power requirement as well, so a good battery + alternator combination is a must. Many people state that their alternators never failed, but mine was shot at approx. 133,000 miles/12 years. For battery, I recommend Interstate Battery and for alternator, I would go with a rebuilt Bosch with lifetime warranty (Pep Boys have them).

Keep an eye on it. If the problem does not recur in the next 2 weeks or so, it is probably resolved. If it should recur, visit the nearest Volvo dealer, act like you know exactly what you're talking about, and have them do a thorough diagnosis on the Electronic Engine Control system. The problem may not appear on a generic OBD-II scanner and may only appear on Volvo diagnostic equipment (though most codes should appear on a decent OBD-II scanner). Do not let them talk you into replacing the ECU, I highly doubt it needs to be replaced, unless the "Faulty ECU" code appears on other generic OBD-II scanners as well.

Keep us updated.


JPN

 

JPN, I used the car yesterday it was back to the same problem. How can I check if the MAP sensor I replaced is defective? I will try everything possible before taking it to dealership....like what you said it can be electrical/electronic problem that only volvo can fix.

Maroon
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Hi Maroon,

>it was back to the same problem.

Ouch[:@]!

It must be annoying, been there & done that[8D].

Anyway, I just went over Haynes manual and some models seem to have MAP (Manifold Absolute Pressure) sensor, while others have MAF (Mass Air Flow) sensor. For '96 non-turbo engine, I believe it is MAF sensor. Can you give us the engine ID? It is something like "B5254S", labeled on the timing belt cover. My reply is based on your engine being "B5254S" for now. If so, the engine control is Motronic 4.4 Ver. and has MAF sensor. Haynes does not specify testing procedure, but I believe the sensor either produces voltage or changes resistance IAW the given air flow (it may be the latter, thermistor).But before you suspect the sensor itself, check vaccum lines for leak/rupture, and also refer to the following:

http://volvospeed.com/Repair/maf_secure.php

If all vacuum lines appear normal and the above instruction doesn't solve the problem, the most accurate thing to do is, well, wait if Tech could reply. In the meantime, if you plan to keep your 850 for more than 3 years, it may be worthwhile to invest in a decent OBD-II scanner, such as Actron CP9175:

http://www.actron.com/product_detail.php?pid=16309

Is CEL on, and is it the same code you've had so far? If so, then it might be either the connection to the MAF sensor or the sensor itself. Was the new sensor either genuine Volvo or Bosch? Volvos don't seem to like havingnon-OEM parts (pretty much the same for all makes).

This is my assumption, so don't quote me on this, but in order to check for correct MAF sensor operation, you could perhaps try testing it with a digital multimeter, assuming that there are only two metal pins inside the connector (if there are more than 3 pins, then you need the Volvo factory manual for correct procedure). Hook up the meter, set it at resistance reading (ohm) and blow cold air into the intake, as close to the sensor as possible. If the sensor is operative, the ohm reading should change.

I also wonder if the idle air control valve/throttle position sensor is all right. I have attached 2 images, one is Mass Air Meter and the other is idle air control valve, which is hidden under the plastic throttle cover. See the first attachment, was that the component you've had recently?

This is the best I can do for now. I'm sure Tech could give you better suggestions than I could.

Keep us updated.


JPN

 

Hi JPN,

Engine ID B5254S, about vaccum lines I'm not sure exactly which one are you referring too....I checked the lines, hose, like what I metioned to you intake hose has hole but was patch using duck tape, the tape is still intact. The CEL is on and it was pulling the same code on different scanners. About your attachment it was the first one AirMassMeter. I followed the instruction on the link you posted from volvospeed.com....it's running good right now, not sure how long it will last... I am hoping that will solve the problem.
I'll keep you all updated.

Maroon
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Good evening Maroon,

It does sound like the problem is still at or around the MAF sensor, if the same code keeps appearing.
There are not many vacuum lines on 850s, and many of them are hidden under the plastic cover on the throttle body area. The cover is held by one Torx screw only, and easy enough for anyone to remove it. Then, with a flashlight, visually inspect the vacuum lines, they are shaped like "L", and are attached around the throttle body area. Some are attached to the relay bay, which is attached on the radiator. Make sure none of them has loose/disconnected connections or has cracks.

I'm still curious about what brand MAF sensor was installed, as well as the manufactured country. I'm a bit sick now, so this is the best I can do for now, I apologise. If you've kept the original MAF, you could perhaps swap them, or wiggle the electrical connector while the engine is running to see if the engine responds.

EDIT: In addition, can you follow the electrical wiring from the MAF connector to see if there's a chafed section (inside metal conductor being exposed, etc...)? There may be a chafed wire insulation that is either about to break or touching metal parts in the engine. Cars use the entire body & engine as the ground, so if there is a chafed wire insulation and if the conductor is touching bare metal inside the engine, it could cause a short-circuit. Or, there may be exposed wires that are touching each other, causing short-circuit.


JPN

 

You are probably somatizing your immigration situation. You have to leave the US in two days, right?

Best of luck,
Axel

 

Hi Axel,

Yes I'll be flying out on Friday, damn it[8D]. But I'll do whatever I can to come back to North America. Working & living in Japan is a nightmare, because ofa number of discriminations & narrow-minded island mentality[8D]. However, I still trust their industrial products, except they are getting worse lately, thanks to outsourcing plants/factories to xxxxx[8D]. Even Sony went down the hill, for lap-top batteries catching on fire[8D]. But rest assured, Lexus/Acura/Infinityare still made there.

Well, after spending over 11 years in the U.S., Japan is a foreign country to me[8D].

I think I've used too many[8D]'s this time. I'll be accessing here from Japan, I'll let you know.

Best regards,


JPN

 

JPN, I'll double check all connections close to MAF sensor and throttle body on my day off. I'll let you know if I find out something. Good luck on your trip...Japan, nice place I've been there once. (Nagoya)

Maroon
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