Hi, I have an '89 740 wagon (non-turbo) that won't start due to it flooding the cylinders with gas. If the car sits for a couple weeks, it will run for 20 seconds or so before it floods out. Once it's flooded, it won't run again until it has a chance to dry out.

Code indicated mass air flow or O2 sensor. Sensor is new, swapped out mass air flow and no difference. Tried different ecu. New fuel pressure regulator just installed.

Fuel injectors' ground was checked, and pulse is appropriate. Injectors are all functioning OK. Mechanic pulled plugs and cranked the motor. He said it's pumping too much gas, but that it's not "just pissing it into the cylinders".

I'm sure I'm forgetting something. Timing belt and tensioning pulley are brand new. Recently tuned. Brand new plugs, which have been cleaned a few times now. Compression is fine. Car runs great until it floods out. starts immediately after sitting for weeks, but then dies.

Is there some component in these cars that may have gone haywire, some sort of throttle control or something? I've already spent too much money on this. Up until this point car always started and ran great. It's been pampered with Volvo parts and top notch service. I've got 2 mechanics scratching their heads over this one. Any suggestions would be very much appreciated.

I don't believe it's mechanical, that's been thoroughly checked. I think it's more likely an electronic component somewhere.

If we can't get it going, I'll be looking to sell this car to anyone believing they can get it going or for parts. Still looks very good, loads of new parts I won't list yet. I'd much rather git it going.

Thanks for any help.

Scott

Forgot to add,check also if you have fuel in your engine oil!.

Thanks for the responses.

Yes, there's also fuel in the oil.

The ECT sounds like the new prime suspect. I'm passing the info in the FAQ along to my mechanic. I'm no longer using the local indie mechanic, and helping a friend who has a garage and is a good mechanic become a Volvo guy. He resisted some, but is starting to come around and appreciates some of the quality he's seen. He originally worked almost exclusively on domestics, but has more and more foreign cars in his shop.

Anyway, he'll be looking at the car sometime next week. I'll let you know how it goes.

Is the diaphragm mentioned in another post something I should look at?

Thanks George - that info may be just what I needed. As I mentioned, I'm about ready to pull the plug. Already dumped close to $500. on this problem.

Scott

Hi Scott.
I doubt you have a failed diaphragm,because if this is the case then there won't be any pressure going to the injectors.
Anyway to test for a failed diaphragm,pull the vacum hose going to the fuel pressure regulator (engine off)and verify if there is any fuel in that hose,then try to start the engine,if fuel gushes out from that hose then of course you have a failed diaphragm.You can get more info about the FPR in the FAQ under(Engine:Fuel injection).
Hope this helps and best of luck.
God bless.
George.

Hi Scott.
The engine has 2 temp sensors,one for the gauge mounted in the head under intake header #2 and another one for the fuel injection mounted in the head about under intake header #3 intake,and this last one is the ECT sensor.
If the ECT sensor is bad the ECU thinks the engine is cold and start dumping too much fuel to the engine.
Inspect also the electric wire connection to this ECT sensor.
Check the 700/900 FAQ under(electrical:Engine sensors) for more info about this subject.
Hope this helps,and keep us posted about your findings.
God bless.
George.

The ECU could cause this problem if it's gone bad--
Poolman

FPR diaphragm is blown. Maybe?