Volvo RWD 700 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 9/2014 700 INDEX

[<<]  [>>]


 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

1989 780 Turbo won’t start. 700 1989


Hi,

Right off the top take the idea of the engine block NOT being machined will make it run and then stop.
You need to put that thought over into a corner of your mind or even out back somewhere! 😊

If the engine was truly rebuilt by removing the pistons and replacing the rings can be quite normal.
The bores get inspected for size and taper and a tolerance is allowed over the piston size. In many cases on these blocks the metal is so good it’s all that’s needed. Just put back in a cross hatched swirl finish of the bore to help the new rings seat themselves and all is good for the block.

I agree with all Dave Steven’s historical statements that you are probably not getting too much gasoline but not enough air on start up. Interpretations can be interchangeable.

The IAC has to be wide open on start up.
Dave brought up differences in systems for the reason of not only ignition but the IACs could be different.
Later models have a spring return to closed and is only powered open.
The other older IACs will have three pins because they were powered open and shut.
In either one if it does not open you will have the same problem.

If ever you get it to firing it cylinders does the engine rev up and back down to an idle?
Both IACs have to demonstrate that performance or it is bad or at least sticking.
Putting you foot on the throttle can allow more air to clear the plugs of gasoline but at the same time you are defeating the startup mode of the ECU. The throttle switch gives you up in that you want to accelerate and you are getting more injection pluses. Not good!
Keep your foot off the pedal. Make sure the throttle switch is clicking to tell the ECU you want IDLE or a STARTUP mode.
With the ignition system working and it’s RPM signal can tell the ECU which one to do.

You are supposed to start the car with only your key twist and touch nothing!
If not it’s a sign that something is out of adjustment or failing otherwise!

You could have a hesitant fuel system relay or some old fuel pumps.
If it flooding that’s probably not the case.
Your statement of wet plugs puts things back it’s getting too much fuel but in actuality it’s not enough air!

Is this car you’re working on, from your first post, have a know history with you, prior having the engine out, that it all worked?
Big difference between it’s your car or a barn find with hearsay. 🫣🤫😊

Phil






THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD

New 1989 780 Turbo won’t start. [700][1989]
posted by  240WStick  on Wed Sep 25 13:29 CST 2024 >


<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.