The Hot Start Saga - Accumulator replacement

[Beachdrifter]

Hi all,

So I thought I wouldn't ever get to this, but here I am after 8 yrs of ownership. It's my turn, lol.

A few times already my car has not been wanting to start on a warm start-up; starts just fine cold.

I'm pretty sure it's the accumulator going bad. I did the air pressure plate test, and after 20 mins, the plate was already very "soft" to the touch. Not holding any rest pressure at all.

I'm pretty sure I don't have the original fuel pump, because everything still looks pretty new down there by the tank. So I will rule out any check valve issues, or less likely. I read some of the other posts already, very informative! I recall the accumulator is still the original one, it looked pretty nasty a few years ago when I was under there.

It doesn't looks too hard to remove and replace. I can't remember exactly if the part is closer to the front or aft section of the car. Which end of the car should be jacked up to better reach the little culprit? I will also make sure to order the OEM Bosch unit.

Thanks, any insights appreciated,

-Randy

[Bitsyncmaster]

You will want both ends elevated. What I do is drive up on ramps and use two floor jacks to lift the back.

Easy on the jacks if you back up on the ramps but takes a little more skill in a garage.

[David T]

Hi all,

So I thought I wouldn't ever get to this, but here I am after 8 yrs of ownership. It's my turn, lol.

A few times already my car has not been wanting to start on a warm start-up; starts just fine cold.

I'm pretty sure it's the accumulator going bad. I did the air pressure plate test, and after 20 mins, the plate was already very "soft" to the touch. Not holding any rest pressure at all.

I'm pretty sure I don't have the original fuel pump, because everything still looks pretty new down there by the tank. So I will rule out any check valve issues, or less likely. I read some of the other posts already, very informative! I recall the accumulator is still the original one, it looked pretty nasty a few years ago when I was under there.

It doesn't looks too hard to remove and replace. I can't remember exactly if the part is closer to the front or aft section of the car. Which end of the car should be jacked up to better reach the little culprit? I will also make sure to order the OEM Bosch unit.

Thanks, any insights appreciated,

-Randy

The accumulator is pretty close to the center of the car so you really should figure a way to lift the whole car. A floor jack and 4 jackstands is the way to go unless you have access to a lift. The main thing is to not damage the hard lines. Also take precautions to prevent the fuel from getting into your face. You can undo the small hose and then undo the large hard pipe. Let it hang down and undo the other large hose. Take note of the positions of all of the fittings so when you tighten things up you don't twist anything. Use 2 wrenches, one to "hold back" so you don't twist anything. No smoking during this procedure! I do not like ramps. Possible to drive over the end and I saw one tip over sideways once, they are not that stable, especially if the floor is not flat and level.
David Teitelbaum

[Rich]

I recall the accumulator is still the original one, it looked pretty nasty a few years ago when I was under there.

It doesn't looks too hard to remove and replace. I can't remember exactly if the part is closer to the front or aft section of the car. Which end of the car should be jacked up to better reach the little culprit? I will also make sure to order the OEM Bosch unit.


You probably have the right diagnosis - bad accumulator. Even if you're wrong you'll be doing yourself a favor getting the original one out of there.

If you do not have proper gear for getting yourself under the car safely to do this work then, as always, you can shop this job out. These fittings are TIGHT and the backing wrench has to be firmly in hand. And make sure you bleed off the fuel pressure - there could be some - so you don't spill too much fuel.

Any decent Euro import car mechanic can pop the car up on the lift and get the job done fast and reliably. It's no more than half an hour, including everything. Ask if they work on Bosch FI systems and if they warrant their work first.

It's a great way to make new friends.

[Beachdrifter]

Thanks everyone for the tips,

Definitely will take it all into consideration. I have the 4 jack stands, so I think I will go that route. Safety always in mind. Applying back pressure when loosening the fittings is always good practice too.

We shall see if it's the accumulator! Part is on order, will update on any outcomes once I install it.

Thanks :)

--Randy

[djdogbone]

Here's an interesting thing that happens to my car with regards to starting.

In the morning, it starts up fine. However, after Sitting in the parking lot at work (in the sun), I have to crank it for a while before she "sputters to life"; unlike the morning when she starts up with no issues.

Also, if I manage to park in the shade, she starts up fine.

I've had the car only a month so I'm just learning about her.

Based on what people have said, I think it's the fuel accumulator.

Thoughs?

[Bitsyncmaster]

Here's an interesting thing that happens to my car with regards to starting.

In the morning, it starts up fine. However, after Sitting in the parking lot at work (in the sun), I have to crank it for a while before she "sputters to life"; unlike the morning when she starts up with no issues.

Also, if I manage to park in the shade, she starts up fine.

I've had the car only a month so I'm just learning about her.

Based on what people have said, I think it's the fuel accumulator.

Thoughs?

Exatly what I found with my D. I narrowed it down to 3 to 3.5 hour rest time in the hot summer sun. Not to say all engines do this but mine was fixed with my RPM relay that extends the rest pressure time 3 more hours.

[Rich]

In the morning, it starts up fine. However, after Sitting in the parking lot at work (in the sun), I have to crank it for a while before she "sputters to life"; unlike the morning when she starts up with no issues.

Also, if I manage to park in the shade, she starts up fine.

I've had the car only a month so I'm just learning about her.

Based on what people have said, I think it's the fuel accumulator.


And you have no problem with hot restarting, for instance, after refueling? And there is no smell of leaking fuel after the car sits?

In any case the PRV engine should catch within 2-3 sec if not sooner under all conditions. Cranking it for a while isn't good for anything in the car. It will probably get worse unless you address it.

If the RPM relay suggestion works, great. The other likely root cause is a fuel rest pressure problem caused by a leak. Accumulator, fuel pump chk valve or other components in the primary pressure circuit can cause this.

Many threads on that subject.

[rothsean]

And you have no problem with hot restarting, for instance, after refueling? And there is no smell of leaking fuel after the car sits?

In any case the PRV engine should catch within 2-3 sec if not sooner under all conditions. Cranking it for a while isn't good for anything in the car. It will probably get worse unless you address it.

If the RPM relay suggestion works, great. The other likely root cause is a fuel rest pressure problem caused by a leak. Accumulator, fuel pump chk valve or other components in the primary pressure circuit can cause this.

Many threads on that subject.


So what does that relay do, how does it prevent the hot start issue?

[rothsean]

Also, what size fuel line is that from the fuel pump to the metal fuel hoses in the fuel pump compartment?

Mine say 7.5 x 3, whatever that means??

Reason I ask is that I may have to install an inline check valve and I want to order the correct size.

[Bitsyncmaster]

So what does that relay do, how does it prevent the hot start issue?

My solid state RPM relay will do a half second "prime" once an hour for three hours after you have run the engine for 5 minuets. The is an option which the user can jumper to disable or enable that funtion. Your accumulator has to hold pressure for one hour for it to help with warm starts.

[DMCMW Dave]

Recall that the temperature setting of the thermotime switch is about 95F. If the car is parked in the sun on a hot day (or in a hot garage), it will never fire the cold start valve. If you happen to be running a slightly lean base setting it will be hard to start.

I'm sure there is variation between thermotime switches as well.

[djdogbone]

To answer your questions,

I can start and stop the motor all day.

The car does not have any leaks that I can see and nothing is left on the garage floor.

Other than what ever slight gas odor you get when you fill up and car, there is no pungent gas smell of any kind.

[Beachdrifter]

Hi all,

Interesting thread since my last post. Today I replaced the Accumulator. So here is the follow-up. It's evening time not, but I have started and stopped the engine several times, checked for leaks and tightened and necessary.

What I have noticed since replacing it is the rest pressure is being sustained for over an hr, compared to only like 15 mins with the old one. I did the air pressure plate test. So that in itself is a good sign. Prior to replacing it I had intermittent hot start issues.

I'm waiting for tomorrow to take it out for a drive and test the hot start if I can.

But one thing I did notice while I was down there are the other fuel fittings in the VERY tight spaces above and to the right of the accumulator. How in the world does anyone get to those fittings?? It looked almost impossible to stick a wrench up there and try to loosen those metal fittings? Just out of curiosity.

I only replaced the accumulator and none of my lines.

Thanks,
--Randy

[Tillsy]

But one thing I did notice while I was down there are the other fuel fittings in the VERY tight spaces above and to the right of the accumulator. How in the world does anyone get to those fittings?? It looked almost impossible to stick a wrench up there and try to loosen those metal fittings? Just out of curiosity.

If you remove your centre console you will find this:
http://dmctalk.org/attachment.php?attachmentid=21389&d=1376800638

If you peel that cover off you will find this:
http://dmctalk.org/attachment.php?attachmentid=21390&d=1376800686

[Beachdrifter]

If you remove your centre console you will find this:


If you peel that cover off you will find this:


Interesting, great pics. Thanks for sharing! Hope I never have to mess with those, but now I know just in case.

[Beachdrifter]

One of the things I noticed was that the larger of the flexible lines from the accumulator (next to the hard line) had a cracked outer "rubber" shell. What appeared to be rubber, looked liked plastic as I started to peel the layer off the line ; all these plastic little hard pieces started falling off. This exposed a nice white mesh underlayment. I doubt the upper layer (which would be exposed to the elements) was a primary pressure barrier since it was so thin and "plastic" like. It appeared that the real pressure layer material was actually rubber underneath the white mesh. I can only assume it was original, but other than that, the hose looked good to me with no other evidence of wear.

Is there actually rubber underneath this white mesh?
Anyone else experienced this as well?
It didn't look like it was leaking or under any stress.

Thanks,

[David T]

One of the things I noticed was that the larger of the flexible lines from the accumulator (next to the hard line) had a cracked outer "rubber" shell. What appeared to be rubber, looked liked plastic as I started to peel the layer off the line ; all these plastic little hard pieces started falling off. This exposed a nice white mesh underlayment. I doubt the upper layer (which would be exposed to the elements) was a primary pressure barrier since it was so thin and "plastic" like. It appeared that the real pressure layer material was actually rubber underneath the white mesh. I can only assume it was original, but other than that, the hose looked good to me with no other evidence of wear.

Is there actually rubber underneath this white mesh?
Anyone else experienced this as well?
It didn't look like it was leaking or under any stress.

Thanks,


That covering is only to protect the weave underneath which provides support and strength for the inner pressure barrier. What you can do is rub off the rest of the loose rubber cover and then wrap the hose with a good electrical tape. Same for the 2 hoses by the fuel pump.
David Teitelbaum

[NightFlyer]

One of the things I noticed was that the larger of the flexible lines from the accumulator (next to the hard line) had a cracked outer "rubber" shell. What appeared to be rubber, looked liked plastic as I started to peel the layer off the line ; all these plastic little hard pieces started falling off. This exposed a nice white mesh underlayment. I doubt the upper layer (which would be exposed to the elements) was a primary pressure barrier since it was so thin and "plastic" like. It appeared that the real pressure layer material was actually rubber underneath the white mesh. I can only assume it was original, but other than that, the hose looked good to me with no other evidence of wear.

Is there actually rubber underneath this white mesh?
Anyone else experienced this as well?
It didn't look like it was leaking or under any stress.

Thanks,

Yes, I personally experienced it.

The cracking, peeling/flaking off, and sticky feel of the outer layer of the stock/OEM soft line fuel hoses is typical, and while it doesn't affect performance of the hose, in theory it is caused by a prolonged storage of ethanol laced fuel in the fuel system, where the ethanol has vaporized and permeated out of the hoses (destabilizing and pushing the outer layer of the stock/OEM hose off).

You're correct in that underneath the white mesh layer, there is a layer of rubber. However, the core of the stock/OEM hoses is actually plastic, that is thermal-pressure bonded to the metal barb fittings, and in theory is susceptible to drying out and cracking when faced with prolonged exposure to ethanol blended fuel and air (which is more susceptible to being introduced into the system if the car sits with ethanol blended fuel in the system for prolonged periods of time as opposed to being driven regularly), and will eventually lead to hose failure.

But, if you're driving the car regularly (don't let it sit with ethanol blended fuel in the system for longer than 2 weeks at a time), then it should be OK as long as you don't have any leaks.

With all that said, I ended up replacing all the soft line fuel hoses from the fuel tank to the fuel filter with hose specifically designed for use with ethanol blended fuel.

Hope this helps answer your questions.

[Beachdrifter]

That covering is only to protect the weave underneath which provides support and strength for the inner pressure barrier. What you can do is rub off the rest of the loose rubber cover and then wrap the hose with a good electrical tape. Same for the 2 hoses by the fuel pump.
David Teitelbaum

Thanks again David! I searched and searched the forums but didn't see anyone else experience this.

I actually went and got some excess rubber tubing slightly larger than the line, cut it to length, and wrapped it around sealing with electric tape. I figured this would be more than enough to protect the weave underneath. I left the line in place because it did look strong enough otherwise.

[Beachdrifter]

Yes, I personally experienced it.

The cracking, peeling/flaking off, and sticky feel of the outer layer of the stock/OEM soft line fuel hoses is typical, and while it doesn't affect performance of the hose, in theory it is caused by a prolonged storage of ethanol laced fuel in the fuel system, where the ethanol has vaporized and permeated out of the hoses (destabilizing and pushing the outer layer of the stock/OEM hose off).

You're correct in that underneath the white mesh layer, there is a layer of rubber. However, the core of the stock/OEM hoses is actually plastic, that is thermal-pressure bonded to the metal barb fittings, and in theory is susceptible to drying out and cracking when faced with prolonged exposure to ethanol blended fuel and air (which is more susceptible to being introduced into the system if the car sits with ethanol blended fuel in the system for prolonged periods of time as opposed to being driven regularly), and will eventually lead to hose failure.

But, if you're driving the car regularly (don't let it sit with ethanol blended fuel in the system for longer than 2 weeks at a time), then it should be OK as long as you don't have any leaks.

With all that said, I ended up replacing all the soft line fuel hoses from the fuel tank to the fuel filter with hose specifically designed for use with ethanol blended fuel.

Hope this helps answer your questions.

Yes, this is great info! Thanks for going into this explanation; getting to know exactly what this hose was made of was part of my curiosity, since it appeared different than the other fuel lines in the engine compartment. Appreciate it. I drive my car at least a couple times a month on weekends. I don't suspect any issues at the moment, but I guess I should consider replacing it eventually.

[NightFlyer]

Yes, this is great info! Thanks for going into this explanation; getting to know exactly what this hose was made of was part of my curiosity, since it appeared different than the other fuel lines in the engine compartment. Appreciate it. I drive my car at least a couple times a month on weekends. I don't suspect any issues at the moment, but I guess I should consider replacing it eventually.

It is different than the soft line fuel hoses used from the fuel filter to the fuel distributor, and fuel distributor to injectors / other K-Jet parts / return line, which all consist of a black plastic core (the other soft line fuel hoses have a clear/white plastic core) and rubber outer layer - no mesh sheathing or rubber/plastic composite covering like the fuel tank and accumulator soft line fuel hoses. Why different style stock/OEM hoses were used in the various locations - I honestly couldn't tell you. Only that the hoses from the fuel filter to the fuel distributor and fuel distributor to injectors / other K-Jet parts / return line appear to have held up better over time and exposure to ethanol blended fuel than the other style hoses.