'94 850 GLT 2.4 L won't start hot

kspeaks · Post by **kspeaks** » 28 Sep 2007, 19:52

O.K., I read the posts and changed the coolant sensor and thermostat, and refilled with new antifreeze. I thought this was the solution at first, because it worked for 1 day.

Now I really have problems! The temp gage is bouncing up and down after the car warms up. and the idle and injection is wavering (acceletarting up and down on it's own), and on the highway, the temp gage pegs down to cold when I accelerate.

This extreme also produced an engine code 1-2-3.

Today I put a new thermostat in because I thought that it was stuck in the open position (keeping the car from reaching the proper temperature for operation). That worked for 5 miles, then back to the gage bouncing and rough idle again, and won't start hot.

I have to wait 5 -10 minutes for the car to cool before it will start.

I also changed the fuel filter. Made no difference.

I got the part for the sensor and thermostat at a local chain store (not a dealer part).

One post said it might be one of the fuel pumps. Which one, and how do I test?

Things have gone from bad to worse. I really want this car to go another 10 years--help!

KW

Post by **MadeInJapan** » 28 Sep 2007, 21:43

Temperature gauge bouncing is not a fuel delivery problem. My thinking is the wiring on the sensor. Check it closely.

kspeaks · Post by **kspeaks** » 28 Sep 2007, 21:58

Well, wires look O.K., I even sprayed electrical connector cleaner in the connection housing; Where else should I look for wiring problems...the wires lead past the generator under the engine into some "un reachable" "un seeable" abyss!

I thought of unpluggin altogether and seeing what difference that makes...but imagine that wouldn't work at all... error code to tell the ECU that there is no ECT signal; followed by failure to start at all...

Any possible issues with NON Volvo parts for stuff like the ECT or Thermostat?

it is a '94 850 FCOL, somebody has had to have had this trouble before!
Everything else posted happend to me and my 850: 1) odometer 2) glove compartment 3) fuel filter 4)antennae mast....

Thanks! Please keep posting. I have only this car and I have to get to work, (and cannot afford the dealer drain).

Post by **MadeInJapan** » 29 Sep 2007, 07:05

I really don't know what to say. You might compare your actual parts (physical appearance, etc.) to the ones sold on line, such as at www.fcpgroton.com www.ipdusa.com and eeuroparts.com

Maybe Robert or someone else will chime in if that doesn't work- I'm thinking it's time to find the pins that correspond to the temp. sensor on the ECU side and test them with an ohm meter but that's really beyond my knowledge here.

kspeaks · Post by **kspeaks** » 29 Sep 2007, 08:19

MIJ,
Thanks. I checked the part. Only difference is that the new part came with an Aluminum washer the old one didnt' seem to have. But Bay-13 said to make sure the new sensor had the washer.

bummer. I guess I'm down to "plug and play" with every sensor I can imagine.

Although the car was not starting hot previously; it was running smoothly in all other respects.

One other clue:
I cleaned the MAS with non chlooriniated brake cleaner...recommeded by a mechanic. I did this when I changed the thermostat and ECT. However, the original problem still exists--wont' start hot, which we all thought was the ECT. Now still having the start problems, and erratic temp signals while running on the interstate.

Thanks for suggestions!

kspeaks · Post by **kspeaks** » 03 Oct 2007, 21:32

It was the fuel pump relay switch.

Also, the ECT was NOT the problem (until I replaced the ECT, and it was a bad sensor from the car part store--not OEM).

So trouble with temp etc was the bad sensor!

Lesson: get the diagnostic equimpent !

Lesson II: Don't trust non OEM parts (especially with electrical components)

Thanks everyone.

What can I expect next from my 94 850?

already got the antenna, odometer, fuel filter, oxy sensor,
I know: where can I get a cabin filter adapter kit cheap?