I have a 740T wagon w/ B230. I've only had the car for 3 days and after it sat for 2 full days, it wouldn't start. It's definitely flooding; all 4 plugs were wet upon inspection. Dried them out, tried again--same thing. No start, smell of fuel. It started fine when it was warm.

I've been scanning through the posts and 700/900 FAQ on fuel systems and I am suspecting it may be the Fuel Regulator not properly controlling volume to engine. Not being very familiar with Volvos, I'm really not sure.

Can anyone offer insight into this problem? All help is appreciated.

Norm Cook

I presently have a customer with a newly purchased 740GLE. The vehicle has 105000 km(app 63000miles). It is a 1988 model, in very good and pampered condition, purchased from the original owner. The car is very hard to start when cold or after sitting for a few hours even when hot. Over the three weeks she has had the car, it has failed to start numerous times.
I have traced the problem to flooding when cold. If I remove the fuel pump fuse, the vehicle will start right away, but of course stall within seconds because of lack of fuel. I have found it starts good if the accelerator is depressed fully on cold starts.
I have determined the problem to be excessive fuel pressure, my gauge shows it to be 75 to 85 psi (I believe over double what it should be). I have checked the return line from regulator to tank, it is obstruction free. If I dead end the return line to tank momentarily, the pressure spikes to over 150 psi.I have replaced the fuel regulator, the pressure remains high, at up to 85 psi.
Checking into the history of this vehicle, an original Volvo dealer work order dating to November 1988 notes this starting problem as a customer complaint in the w.o. text. It does not say what steps the dealer took to alleviate the problem.
I am still contemplating where to turn to next...
Car runs beautifully as soon as it goes into closed loop mode, as the ECU cuts back on the injector pulses as per exhaust sensor readings, consequently fuel mixture is leaned out to proper values.
Help!!

I presently have a customer with a newly purchased 740GLE. The vehicle has 105000 km(app 63000miles). It is a 1988 model, in very good and pampered condition, purchased from the original owner. The car is very hard to start when cold or after sitting for a few hours even when hot. Over the three weeks she has had the car, it has failed to start numerous times.
I have traced the problem to flooding when cold. If I remove the fuel pump fuse, the vehicle will start right away, but of course stall within seconds because of lack of fuel. I have found it starts good if the accelerator is depressed fully on cold starts.
I have determined the problem to be excessive fuel pressure, my gauge shows it to be 75 to 85 psi (I believe over double what it should be). I have checked the return line from regulator to tank, it is obstruction free. If I dead end the return line to tank momentarily, the pressure spikes to over 150 psi.I have replaced the fuel regulator, the pressure remains high, at up to 85 psi.
Checking into the history of this vehicle, an original Volvo dealer work order dating to November 1988 notes this starting problem as a customer complaint in the w.o. text. It does not say what steps the dealer took to alleviate the problem.
I am still contemplating where to turn to next...
Car runs beautifully as soon as it goes into closed loop mode, as the ECU cuts back on the injector pulses as per exhaust sensor readings, consequently fuel mixture is leaned out to proper values.
Help!!

First you need to figure if you have spark. My guess is no.

Aleekat;

Sorry--lack of info. Yes, that's the first thing I did.

Took off dist cap to see if any moisture had gotten in (recently (carefully) powerwashed motor)and also checked spark from coil which was OK.

Norm

You very likely DO have spark—otherwise the FI system will pump no fuel.

Your hunch on the Fuel Pressure Regulator is a good one. Remove the vacuum hose at the FPR and check for signs/smell of fuel. There should be none.

If the FPR diaphragm leaks, fuel will be sucked directly into the
intake manifold.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Bruce;

I revisited the 700 FPR FAQ and, after identifying which part is my FPR, I realize mine looks brand new.

My understanding is that both pumps were replaced and it looks as though the FPR is new too.

If this checks out OK, what's the next step?

Norm

Norm,

Even if it looks new, check the vacuum line to the FPR please. If that's not the problem, the fuel must be getting injected normally. So if the fuel is there, and there is spark at the plugs....hmmmm. Time to grasp at straws?

Maybe the timing belt shed some teeth? Or broke? Is there spark at all the plugs?
Look in the oil fill hole to see if the cam turns when cranking.

If it does, hand turn it to 0° TDC for #1 (Pull the plug and stick something in to verify that the piston is up) and see if the camshaft timing mark agrees.

If those things check out, it might be excessive fuel coupled with weak spark. The fuel part could be due to a bad Engine Coolant Temp (ECT) sensor telling the ECU it's below zero. The FAQ tells how to check ECT resistance from the ECU connector, I think.

That's all I have at the moment. Hope the experts get on board soon.

Bruce
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Bruce;

The vacuum line did look at bit weathered so I'll change that and eliminate as
problem.

Oddly enough, AS SOON as it wouldn’t run it started to turn over faster. ?? The faster engine rotation sounds similar to when the plugs are out during a compression test. Having heard this, the first thing I did was check to see if the cam was moving and it was.

Maybe the T-belt did jump some teeth ... this could potentially throw off the timing enough for the cylinders to not have compression and thus the increase cranking speed would make sense.

I'll check for spark, then TDC on #1 with matching timing marks(hopefully).

If it's turning over fast, there's a chance you've dilluted your oil enough to reduce compression. Check the oil level and aroma.

As for your rich running condition, I'd suspect the coolant temp sensor. On an LH-2.4 car, assuming you can keep the car running, you may see the MIL lit and the stored code would be 1-2-3.

--
alex

'89 765T, 171,0xx mi

Alex;

It started to turn over quicker only on the 2nd time I tried to start the car so it wasn't from excessive gas in crankcase.

I looked under the FI and there seems to be 3 sensors plugged into block/head. Which one is Coolant sensor? If the sensor is sending a "closed" signal to fuel injector (IE cold and needs lots of fuel) then can I simply unplug to bypass?The engine is B230FT.

Norm

Norm,

I hope you haven't bothered to change that vac line. If no signs of gas, its probably OK. But they do sometimes get "split ends", leak vacuum, and rais fuel pressure needlesly.

But that Fast Cranking is, IMO, the tip off to T-belt problems.

I hope you have good news tomorrow.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I took the line off as you suggested and it was dry. As I mentioned, it looks new so I'm guessing it isn't the problem. A few of the vac lines are old and cracking and needing replacement but it wouldn't kill the car such as has happened. It DID work for a few days.

There's spark coming to #1 plug. Took timing cover off and had my wife fractionally turn over and all of the belt is intact and still in good condition.

Tried car again (with foot on floor) and still nothing. Plugs soaked again too.

Alex suggested it may be the coolant sensor. That will have to be tomorrow's job.

Norm

You can have spark to coil, but no spark to plugs.

Yes, true enough.

I will verify spark is getting to plugs as well. I have no reason to believe the spark would not be distributed properly but I need to rule that out.

Lucid suggested the FPR so that will be the next step.

Norm