I am new here and have exhausted myself for weeks now with my 94 Volvo 850 wagon. i have been to shop after shop and gotten so many possible answers and quotes. here is what the car is doing one day i left from the dentist and after leaving the parking lot the car started running rough and if i came to stop at a light it would act as if it wanted to shut off, i vibrated my way home so i could check it out. after arriving home i checked hoses gaskets and codes got a code for maf signal missing or faulty, also got code for egr flow restricted or low so i removed the egr cleaned it out cleaned the manifold and throttle body changed fuel filter and gas just in case changed fuel pressure regulator vaccuum hoses and vapor canister new spark plugs and cables. so after all that the car is still running erratic it will start fine and idle great for a minute then it will drop to less than normal rpm level and begin shaking violently as for trying to put it in drive or any other gear other nuetral it wih cut off sometimes it will recover and just shake like crazy before i changed the other parts though and did the cleaning if you put it in gear and held the gas it still would cut off no power at all but now after the cleaning and changing of parts it brought back some power. i had to idle the car a little high to keep it running when in gear otherwise at normal idle it would cut off. the crazy thing is at first it will run as if nothing is wrong it will idle fine and even go into gear and drive at normal rpm but after awhile of running it would start stalling especially when approaching lights or sudden stopping sometimes it would recover and go to a normal idle but i know eventually it will start running rough again. i checked the egr solenoid it is fine the fuel pump relay is good and changed the injector relay as well. what else can be the problem oh and i have recently had a new intake gasket put on could it be the thermostat i brought a used maf sensor maybe that could be it too also i suspect the tps which i am changing this week please someone help i am a new volvo owner and i really want to bring her back to good runnings so we can build some beautiful driving experiences together.

 

What kind of plugs and ignition wires did you use?

Have you checked again for codes? If so, what are they?

Try unplugging the MAF sensor altogether and see how it idles - it will trigger the CEL but it is easily cleared.

...Lee

 

thanks for your response, i am using bosch platinum plugs and dealership wires after reading your post i decided to re-pull the codes to see what i get so i did lastnight first i checked the A-2 port and it gave a maf sensor code but of course that was because i disconnected the IAC to check its operation after that i cleared the codes after having them repeat restarted the car with everthing connected and checked the A-2 port again it gave 1-1-1 No Faults. i then checked the A-6 port for codes and it gave codes 1-5-4 EGR leakage, 2-4-1 EGR flow incorrect, 4-1-1 Throtthle switch signal from fuel injection absent or faulty, 4-1-3 EGR temp sensor signal incorrect or missing. so i am betting i need to purchase a new EGR and a tps sensor, iwas ultimately thinking about bypassing the EGR since they are so expensive unless i can find one in good shape at a local junk yard but if you have any other further advice or suggestions i am all ears this is my first volvo and i wanted the 850 wagon when they first cameout but i could not afford it then so some years later here i am a volvo owner and now i want to get her right.

 

Most of the time with the EGR it is a flow problem and the hole in the intake plugs up and seals shut.
Usually you can pull the intake and EGR and clean everything good and it will work fine for many more years.

Yes it sounds like you need a TPS as well.

 

thanks tech for your response i did in fact pull the EGR valve off and cleaned it soaked it in a lot of carb and throttle body cleaner and thoroughly scrubbed and cleaned the manifold port i am wondering if the pipe that leads off the manifold is clogged i am wondering if i should pull it and check it out but you are right i am in definite need of a new tps i tried everything i cleaned the connectors and added some die electric grease i will be changing the tps on friday and probably cleaning that pipe out too just as a precaution hopefully this resolves the problem i will let you know thanks for your help if you can think of anything else let me know in the meantime everyone enjoy your Christmas merry wishes to all your families.

 

That stuff should fix you all up.

 

Let me begin with
Merry Christmas :-)

In that I have been through 2 of these motors I feel I may contribute a little to this thread...of course I am not TECH, JPN or PSoabic...but here is my take.

I had a very similar issue with one of my cars...let me ask did you clean the MAF? Do you have another MAF to check it with? Did you clean your IACV and check all your vacuum lines? My problem was MAF related although it was not giving a MAF fault...and lastly, did you verify the fuel pressure at the rail? I thought maybe a plugged or partially blocked filter would give similar symptoms...

Ok now I sit back and let the gurus have at my description...go ahead...I know it is coming!

 

Good day all hope you all had a wonderful Christmas and a good New Year to come. ok here is the latest starting on Christmas morning after opening gifts and all that i decided to go out and work on the Volvo, so i made a few adjustments to the throttle body which turned out to get it running a little better the following day i went to the junk yard and picked up a few other items and also visited volvo to get a intake manifold gasket because i was preparing for a tear down in which on sunday i did i put on a new catalyst converter i removed the throttle body and manifold to my amazement it was gunked up with carbon deposits the throttle plates inside the manifold was so carbonized it would only open less than an inch, so 4 cans of throttle body cleaner and some squirts of WD40 on the levers they open up fully cleaned out the entire manifold did another good cleaning of the EGR and the pipe took off some electrical connections and sanded the block clean used some electrical cleaner and die electric grease on the connections cleaned of the grounds redone the pcv system new hoses and clamps gave the throttle body a good cleaning and replaced the TPS and MAF sensor cleaned up my knock sensors everything that needed to be done that i could think of while i had the manifold out i didlubed up the throttle body spring and linkage made a few other tweaks changed the coil pick up and 7hrs later she was running great again God is good i say that because he wouldnt let me give up and pay outrageous prices to some shop who probably wouldnt have done half of what i did so many thanks be to God and to all of you who helped with your feedback. now i beleive it is time for some new wires and distrubtor cap and rotor oh by the way Big ups to Z-max that stuff is great while my manifold was off i looked at my valves and Wow! they looked almost new no carbon build up or anything and the power it gave back is definitely noticable the heck with seafoam Z-Max is the way to go i am skeptic about most products but Z-Max stands up you guys should really try it out. on my next oil change i will be added another Z-Max treatment also i will be changing my timing belt and the accessory belt as well oh i also changed my thermostat i must say this has been a very good learning experience for me i feel as now i know my car better that is the joy of doing your own work to your car you gain a better understanding of your car and no lame mechanic can try to cheat you bullcrap you around cause you know your car. thanks once again and i will contribute any suggestions that i find out that help any of oyu in the future.

 

Glad all is good on the car now!!!

 

quick question though i am wondering if i should change my cables it has a slight miss nothing major but it bothers me any suggestions and also i didnt notice any muffler on my wagon but it has a light roar coming from the tail end.

 

If the wires are OEM then they will have a date stamped on them check them out. If they are pretty old replace them.
If not OEM and you know they are pretty old I would replace them.

The muffler on the car should be basically between the rear wheels.

 

FYR.

http://www.fcpgroton.com/product-exe...ategory_id/327

I do not know why the Bougicord is listed close to $100; they should be around $50.


JPN