I am all tuned in to my 91 740 220k miles wit Rex Regina. Lately it is not starting with the first crank attempt like it always does. It does start on the second attempt and if I shut down then immediately restart it does. BUT leave it for a while it wont on the first attempt. I can hear the intank ( only one pump) whirring away ( priming?) when I turn the ignition key to the pos before starting. I leave the key in that position for a while to see if it makes a difference but it does not. Any ideas?

Have you tried to get fuel pressure reading>? It sounds like either the pump /screen or filter maybe clogged.

So the not starting on first attempt is solved. It was the fuel pump. I took the opportunity to renew the big can like fuel filter as well. I changed the CPS as well.

You get a GOLD STAR for letting us in on your cure - Thanks

Thank you sir!

I would like to clarify the fix for this issue. It was not the fuel pump . It was the device connected to the output side of the only one intank fuel pump on this regina car. This device is called an accumulator or pressure dampener. It became leaky preventing full pressure from reaching up to the fuel rail. It also allowed drainback of the fuel. I bypassed this device with a piece of submersible fuel hose. My search on the internet reveals that many owners did the same without any adverse problems.

Update: I am pleased to say that the car is doing just fine without the "accumulator? fuel regulator?. If you recall I removed it based on a fix that I saw in another Volvo forum. I used submersible fuel hose to bypass this "thingy".

Hi,

Well that’s nice to know even though I do not own a 700 series car.
Interesting that it has only one pump where both the LH systems and K jets used two pumps. One as only a feed pump to the other.
Only the K jet had an accumulator beside the main pump but the filter was up by the engine.
The accumulator left the scene on the LH and got a larger fuel filter to act as a reservoir I would say.
I was assuming that a large filter was on 700s too.

So that device you are saying leaked.
Isn’t this a throw back to the accumulator days? I wonder why?

I’m also surprised that this car has an accumulator or even a pressure damper.
They are not exactly reciprocating pump piston involved.
The main pump in the tank has or should have, a check valve, so I don’t understand why an accumulator should consider stopping fuel also?
So hearing you can bypass it with is a fix doesn’t surprise me or at least it’s halfway.
How did you know that an accumulator was leaking internally?
To where?
I may have forgotten some of the other posts so I’m fine with what fixes this car.

As an example, On a bigger scale of hydronic systems covering many buildings, like a university or a plant operation, there’s several pumps to circulate fluids. These are at various heights and distances.
This system utilizes a lot of bladder tanks for expansion changes mainly from heat demands.

If a boiler goes off line, for any extended length of time, pipes can shrink in length and what were tight seals can start leaking into a rooms from overhead.
And That can get messy fast, Trust me!

As water shrinks during a cooling session, the running or idle pumps can have air pulled in around the shaft seals.
Pumps create suction so Cavitation is not a nice thing. We have burping valves scattered about up in the highest part of the system.
Like the radiator caps and coolant bottles on our cars.

The above is the Same as shutting down a car’s system.
Accumulators have their place but it’s interesting, to me, that this vehicle’s fuel system should need one?
It already has a fuel pressure regulator that can bleed fluid to a holding tank.

Even on the k-jets, I think the accumulator was an engineering overkill to some extent but it’s a mechanical injection with a volume distributor. (??) Someone justified it.
Constantly emitting fuel to an oxygen sensor for feedback to a “adjustment system” including a frequency valve. The mechanical equivalent of a AMM.


We shall see what happens below a half tank or less of fuel.
You might have a suction side leak on the main pumps inlet. You did say It is the only pump.
Did you ever notice differences with tank levels during this time?

Thanks for the information.

Phil

Hi Phil. As far as the Fuel quantity in the tank it seems to make no difference at all. I do have the large Bosch fuel filter and I renewed it during the diagnostic stage. My suggesting that the accumultor was leaky was actually taken from the internet and what other owners had experienced. After removing the sending unit from the tank it did appear that the accumulator was somewhat loose . I had expected it to be much tighter . Not having the required fuel pressure at the rail resulted in backfiring and poor accelerator response. I made another post about the hesitation and backfiring .The only issue I am having now is an idling one. I believe the coolant temperature sensor is bad as the car seems to think it is cold and the revs stays pretty much at 11-12 hundred rpms. I will be removing that sensor a shortly and testing it .

Hi,,

I guess I’m still stomping around in the same tub of grapes, like in an old rerun of I Love Lucy.
On theses cars I can make all kinds of funny faces.
I still don’t know where or what you are calling an accumulator.
I thought on these cars LH cars the oversized fuel filters acted like an accumulator?

You said, “ Not having the required fuel pressure at the rail resulted in backfiring and poor accelerator response” is absolutely correct as the engine will suffer various ailments.

A faster than normal idle is unusual since it computer controlled through the IAC.
In order to get faster excessive air has to get around the throttle plate to where the IAC vane cannot close down far enough.

On newer than 1988 cars the IAC is spring loaded to shut down if not energized.
It has to get a signal to open more or it can stick but the spring is supposed to always close it.
The throttle plate can get adjusted wrong and can cause a high idle.
It basically has to be fully closed but not be allowed to get jammed in the bore too tightly.

Make sure you have no other vacuum leaks and check the throttle plate for proper closure.

The coolant temperature sensor affects mixtures but the computer doesn’t add RPM for a different idle speed on purpose.
Unless, Under startup conditions the instant racing of the engine upwards is normal but will immediately drop down to 750 RPM. It seeks loads only right after the startup command.
The mixture is preprogrammed to the engines temperature, yes!
It stays from in the “cold”start point to “warmup” period area very temporarily.
The transition is preset to the coolant temperature and the O2 sensor in the exhaust coming on line.
The RPM is constantly monitored or built to stay on that 750 RPM.
A throttle switch is a snitcher to make idling transition happen.

IF the engine stumbles the ECU plays catch-up or shut down maneuvers. In abrupt cases, the timing gets adjusted and so you might hear a clack and the knock sensor is there for that.

With all this explanation you are looking for too much AIR or the control of it.
A smooth but too fast of an idle is only one perimeter off its baseline.

The ECU is very fast as it operates in steps but maybe even two or more at the same time.
Some “Adaptive” technology was sneaking into scene in the nineties.
IMO, it seems to never stay dialed in, to where when cold, the idle will be lumpy but RPM stays put @750.
Excessive mixture under certain circumstances is a wider chase but a coolant sensor circuit problems are alway possible. It’s important, yes. Otherwise, the AMM and that fuel Rail is in there and causes a wider Trail of thought for troubleshooting.

What’s been nice with the red block’s drivetrain is that it has all been repairable.
IMO reliable in a rather inexpensively way for over the many years of owning my 240s anyways.

Hope this helps check for the air input while investigating or changing the coolant sensor under that manifold.
Hey you got a whole extra year to do the same thing that you do on New Year’s Day.
Be careful of traditions. (:-)

Oh! the BRICKBOARD might have us for another one too. (:)

Phil

Thank you Phil for your awesome explanations. I'll see what gives and report back. May take some time though.
Regards
paul

On my 240 (same motor) that described crankshaft position sensor. If the motor is warm (let sit for 10-15 minutes are the ignition is shut off, the car will not start on the first try. Second, third, fourth and fifth tries, it fires right up, but not on the first try.

I have replaced the crank position sensor a number of times, but I am to the point, that I just live with the issue. A new crankshaft position sensor is only good for about 40-50k miles.

So I looked up the fuel system in the faqs and there is a section that mentions" failed fuel pump check valve" The symptoms of this is exactly what I an having. Now to find where it is located. Any ideas , if your s is a regina system ?I hope it is not in the tank.

I also saw where someone made mention of of long crank with cold engine before starting that the Fuel pressure regulator should be replaced

IMO, based on the consistency of your symptoms the odds are high it’s the fuel pressure regulator. See the extended FAQ file on that topic
Volvo 700/900 FAQ: Fuel Pressure

In your case there may or may not be running issues as noted in the FAQ, but likely it will be running rich, your gas mileage will be poor and you may well find the plugs are uniformly quite sooty. As per the FAQ there are pressure tests you can do to check the FPR, but in your case I'd go straight for replacement unless you've got the necessary fuel rail pressure gauge to do the tests properly.

Less likely and only if you tend to run on the cheapest gas with minimal additives and/or the pickup screen in the tank is dislodged and/or the car has gone through extended periods of disuse would I suspect a fouled check ball valve in the fuel pump. You could try running a number of tank fulls with a high quality injector/fuel system cleaner additive to see if there are notable signs of improvement. If the pressure can leak down enough in half a day to delay cold startup to the extent you describe then I rather suspect such cleaners wouldn’t be up to the job. Anecdotally, people don’t seem to have much success restoring check valve functionality just with cleaners.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Success!!
So this morning it started on the first attempt , just like it always does. The fix was a new Fuel Pressure Regulator which I installed the night before . I did not suspect this as I was not seeing any gasoline spewing out when the vacuum line was removed nor was the car running rough at idle. It was the original FPR that was removed. Is it a possibility that the o ring might have become leaky? Then again there was no trace of fuel around that area. Ah well , fingers crossed that this is behind me now. Thanks for all the suggestions. Next step is to renew the CPS.

Indeed, FPRs don't always fail as expected, as I also found out.

In my case, the cold engine would start fine but would run rich, splutter and almost die for the first 30 seconds or so. After that, it would run and idle just fine, every time, until it cooled down again.

Slightly black spark plugs predicted some failure developing LONG before error codes and CEL were thrown. Long as in years before. Only near the end did the spluttering start.

So I did the usual checks like smelling for fuel on the vacuum side of the FPR and sticking the fuel return line in a bucket to see a healthy flow. All looked fine. I did not have a fuel pressure meter.

The only clue I had was the already mentioned warming up time of about 30 s. And when I realized that was the time it took the O2 sensor to start giving useful data, switching the ECU from warm-up-program to the normal running program, I decided to replace the FPR anyway.

It turned out to be the right decision.

The injection timing during the warm up is based mostly on ECT, and completely without the feedback of the 02 sensor. This needs for the fuel pressure to be in the ball park. Slightly high, and the mix also becomes slightly higher than intended.

Well,
I hate to say this , but I was premature with my success, thinking the FPR fixed the issue. It is happening again , having to prime a couple times before a good start on the first attempt. At least the car will start so I will have to revisit the issue and see what gives. Will follow up.

Main fuel pump check valve.

That's worth checking, but I am leaning towards Chris Mullet's explanation a bit more.

A faulty check valve would make the pressure bleed back into the tank through only the pump, it has nowhere else to go. So, during the first attemp, if you just kept cranking the engine (meaning the fuel pump will also keep running) wether or not that check valve is not closing properly IMHO wouldn't matter. The engine should start on the first attempt, perhaps needing only a few turns more of the starter motor.

Having said that, if the fuel pump has come loose from its fuel pulsation damper, pressure would bleed straight back into the tank.Some more movement of the pump and it would start to gush and create a no-go situation as the fuel system is now starved.

Neither of these two situations seem to apply clearly.

Now would probably be a good time to buy or borrow a fuel pressure meter.

im not familiar with the regina system . with the 240 and 740's I have they have the pere pump. If the fuel is lower than about half and the pre pump fails it can cause problems that go away with a full tank. dead main pump , car wont start.

you can check it , pull the fuel line off the fuel rail , into a jar. pull the fuse I think it was fuse 11 but check your book.. the idea is the pre pump will pump fuel into the jar and so will the pre pump but the main pump is way more powerful. by pulling the fuse you can tell which is running , you can hear it through the gas cap too.

I'd see if you have adequate fuel flow but be careful of starting fires with gas.

I was just fighting some issues that led to a bad fuel injector, once I pulled off the fuel rail and connected the ground wires back up and tried starting with the coil unplugged I could see the injectors spray but one was stuck and it was continuing to run fuel into cylinder 3 until the fuel rail was out of pressure. that caused a huge amount of fuel to collect in cylinder 3 and upon startup it was basically running on 3cylinders with one flooded until it coughed up enough gas to fire up in that cylinder.

after all that I'd look at that sooner in my troubleshooting sequence. there is a leakdown test you can prerform with a fuel gauge connected. that's more the "correct way" basically the fuel rail should maintain it's pressure not leak the gas into the engine upon shutdown. if you can connect a fuel pressure guage that's probably better and a way a mechanic would approach it but you can check those things with out it.

careful if you pull the fuel rail open and then turn the key, It'll pump a LOT of fuel out quite quickly , if you wanted you could pump it into a gas can and get an estimate of the flow rate.

with having the regina system I could be feeding you info that is inappropriate. I'm not sure what the differences are exactly and it is a different animal.

the relay for the fuel pump caries quite a large amperage and every time it shuts off it makes a spark across those contacts. over time the contacts get blackened. you can likely clean them in a pinch, but best to refresh that relay. I made myself a jumper with a fuse that will run the pump if it is installed.

if the car is ever in a crash you dont wan't it to e pumping fuel after the engine stops so there may be some protection to shut off the fuel if the engine stops. I think in my 240 there is a black relay on the inner strut tower on the passenger side but I could be confusing my 740 , they are very similar. If that relay is pulled the engine will immediately quit as it will shut down the ignition system. with Regina , I dont know probably they have something similar in there.

I don't think it fails as often as the fuel pump relay, maybe because it isn't conducting much amps like the fuel pump one. less amps means the contacts fare better.

I had a no start issue from a bad coil wire, the prmary winding, one was corroded. there may be an engine fuse in around the left inner fender area near the coil. Ive seen the plug for the AMm go green even though it has a boot , I found a bad conection cause me grief there before.

on my car there is a transistor on the inner fender near the airbox , it can fail. I mounted a spare in my 240 so I can just swap the wires over if I suspect it failed. regina may be different. I think it basically amplifies the signal from the ICU to deliver a larger amperage to the coil. Ive never had one fail but evidently they can.

dont forget the obvious, make sure you dont have a loose battery post connection, sometimes it is that simple.

Hi Phil, just an FYI. Dan's '92 240 here won't be Regina, it will almost certainly be LH 2.4 unless it's manual trans with LH 3.1.

Being on the type of injection topic I thought I'd carry on in case you're interested and for the future reference of others here.

The Volvo RWD fuel injection story goes like this:

o The Regina years were 1989-1994 in some 740/940 depending on market and availability, mostly just 940s in North America, with 1993 940 NA pretty much all Regina. None of the 240s, 240/700/900 turbos or 740/940 DOHC 16-valve ever got Regina. Other than those exceptions and 1993 940 NA, within the Regina years you pretty much have to ask.

o The LH years were 1983-1995. In North America these were LH 2.4 for 1989-on 240/700/900, with LH 3.1 in a few 1992-on 240s with manual trans. 1995 940 was all LH 2.4 in both NA and turbo. Previously it was LH 2.2 for 1985-1988 240/740, plus '89 740T (a carryover LH 2.2 year for turbos) and early LH 2.0/2.1 in a few 1983-1984 240/700 (launch years of the 700 series).

o Prior to that, the Jetronic CIS years were 1990-1985 for the first of the fuel injected red-blocks. This was mostly all K-Jet CIS for 1970-1984 late-140, 240, and early 700, with an early version of that called D-Jet CIS in some 140s.

This is for the North American market and there are always exceptions, such as assembly plant, factory orders, owner imports and jurisdictions with different requirements. Production varied by market and sub-market. The main markets were North America, Europe and Overseas. Production often varied by plant, especially the market assembly plants that supplemented production from the main plants in Sweden. The sub-markets are jurisdictions like Canada, California, Great Britain, Japan, and Australia that we see in the green manuals, especially the green manual electrical wiring diagrams.

A lifetime of Volvo ownership and being on this site since its beginnings, I pretty much know this stuff off the top of my head by now so thought I'd pass it on. Would have been nice to have this in the FAQ. Wikpiedia entries are often Europe and often don't accurately reflect the North American market.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Hi,

This is not Amazon Phil but the other Phil on the 240 side.

Your write up on the differences is as wonderful as usual.
I bookmarked it for myself.
I will put on a thumbs up on it too.
So maybe, it will make the BB’s front home page or be found by the search engines.

I was looking up a part number yesterday for rear main seals to purchase less expensively and an article that I wrote 13 years ago popped in. It was a post on the BB and was down a screen or so.
I was surprised to see it let alone that far back. Maybe the WAYBACK machine will hold it too.
I guess a FAQ can be built that way with enough hits.

Keep the information coming as it seems to stick better, in our virtual land, better than cooked noodles on a refrigerator wall.😳

Phil

This may be a long shot, but when I replaced the pump in our ‘90 740 Regina I didn’t get the pump properly locked together with the long flat bracket that is supposed to hold it in place. As I recall the bracket has a square hole near the bottom end that locks onto a matching square section that protrudes from the side of the pump. Consequently the pump ended up “blowing itself” downward, creating a gap between the top of the pump and the bottom of the pulse buffer unit (for lack of a better name). You need a good tight connection there. I had to go back in and correct my mistake.

Good! Failed FPRs don't always have a failed diaphragm that leaks out the vacuum port either as raw fuel or vapour smell as a telltale sign. In your case, the failure would have been it no longer making a good seal internally allowing a slow leak out to the return line to the tank. That this was the original 30+ year old FPR speaks well of the quality.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Thank you Dave

I just found out that the Regina fuel system has the check valve built into the fuel pump.

Nowadays I would suggest the fault lies in the ignition system first.

No. Don't just throw parts at it.

Use multimeter to test continuity at plug cables, rotor and cap.

There should be some resistance reading. If none only then replace them.

When my car wouldn't start (crank ok) recently, I tested the plug cables 2 failed out of 4. There are 4 Otto cycles in our engines. Of course 2 out of 4 wouldn't make it work.

Amarin.

“… It does start on the second attempt and if I shut down then immediately restart it does. BUT leave it for a while it wont on the first attempt…”

Try turning the ignition on an off three or four times (hopefully hearing the pump prime a couple seconds each time), then crank it. It sounds like the fuel may be draining back, leaving the injector rail void of fuel to the point that a single priming shot isn’t enough. A fuel pressure gauge attached to the fuel rail will reveal how fast the pressure bleeds down. I can’t recall what sort of check valve the Regina system utilizes, if any, to prevent rapid drain-back.

Gents , Thank you all for your response. I thought about the CPS as mine is really really rough, the outer sheathing has crumbled away and I wrapped it with aluminum foil to keep it going. I will be ordering a replacement soon. The predictability of starting on the second step had me perform what Chris suggested and yes it worked! I cycled the ignition switch 3 times and heard the fuel pump prime each time. The car started on the first attempt which now leads me to investigate as to how the fuel is "draining" back. It wont be anytime soon as I am busy with other projects , nevertheless I will report back with my findings. In the meantime I am open to suggestions as to where to start.
Regards,
Paul

Hi,

I read the sequence carefully and you are doing and thinking along the right lines to diagnose the systems.
Remember to have the spark distribution system is in good condition first!
I always rule that system into having a priority!

The ECU by itself primes the fuel rail through the system relay of which has two parts.
One half controls the fuel injectors and it may not be making up to ground to power up the injector/AMM circuit so readily.
I would be suspicious of this possibly happening and throwing you off track that the relay is good!

You might try testing for power on the AMM's power wire. On the 240's it has an orange wire.
Art Benstein's method, on Cleanflametrap.com, of putting a small light bulb into the AMM's connector. It helps to observe it's action and give you a peek place inside a central point.


Now the same thing happens, after the CPS sends its signal to the ICU and the ECU and after the engine starts to turn.
Be suspicious of a lazy CPS or its wiring that might be leaking it's output signal to the above components.
Inspect the connector and the sheathing carefully all the way over to the sensors top.
If it is an aging sensor change it or if you think it's an original, put in another one for sure!

Since I'm only a 240 man, I cannot help you with a Regina systems.
I have read that there is little box that can develop internal connection issues!
I think Blindboy has experience it hunting in that area of the electronic ignition world.

This puts me back to the beginning.
On the 240's, I always give up some attention to the power stage relay, about ever ten years or so!
It's a middleman, that fires our ignition coil, by opening and closing the primary side circuit.

This is, Only, because of my nicer west coast environments and my cars are kept indoors as much as possible. (:-)
I don't know how any car survives the North's ice and salts! I'm not sure I would own a car there let alone my many vehicles! I would have a different hobby, like, watching snow fall!


Poke around on the 700 FAQs and other similar postings and you will see issues that point to all of the things I have mentioned.

Good luck fuzzing with that intermittent gremlin, as it's just starting to grin at you!
(:-)

Phil