So the fuel accumulator on both my 99-turbos could use replacement. The one on the silver car, although it looks fine externally has had fuel sitting in it un used since 1984. The grey one I think is likely the original too, and I suspect is what's causing my occasional extended crank times when the engine is warm.

Does anyone know what the 99 turbo SHOULD have? Can I use an accumulator from say a DeLorean? They look physically identical, but DMC-H was selling them last year for $30 on closeout, so I have one sitting here, and can get more... Fittings all fit, it's the same size externally, - it is however intended for use on a 6 cyl fuel distributor. I wonder if anyone knows if this will affect operation in any way?

the PRV unit specked for the DeLorean is a 0 438 170 029 BOSCH p/n (0438170029)

Just removed from the silver 99-T is a 0 438 170 014 / (0438170014) which still looks great externally, but you can hear loose rust rattling around inside it.

Also, that Part number unit that was in the silver 99-T seems to fit the Volvo 262 in 80 which is also a PRV car, so I am going to say, very likely the DeLo PRV accumulator will work. Will report back...

I don't see why it wouldn't, I've hear of people yanking them out of junked Mercedes cars, and the delivery pressure for most of the CIS blocks should be the same.

I seem to remember that most fuel accumulators were pretty much the same. Internally there is a spring inside them that isn't in contact with the fuel. The first 99T I owned had an accumulator that was so rusted out that you could see the spring. The car ran fine and didn't leak any fuel. I wonder if the rust you hear rattling around is just in the area where that springs is and not internal to the fuel system(?)

Brand spanking new one in the black 99t.

The primary difference in the accumulators is volume. Bosch specs these things so that they maintain pressure for a specific amount of time depending on the car model. I've used VW and M-B units on my 99's w/ no problems.

However, your extended crank time probably comes from an internal leak in your CIS system allowing the system to leak down and allow the fuel to boil out of the injectors.
I've found the O-ring at the base of the fuel pump check valve to be to most common culprit.

John

99Super wrote:I've found the O-ring at the base of the fuel pump check valve to be to most common culprit.

John

I was just reading about this in a CIS manual, that does seem like it could be my issue, however I have a very fresh fuel pump in the car and the CIS system does seem to maintain pressure. Paul H says "It's just a K-jet 99, this is typical operation" I am starting to think this is the case...

"It's just a K-jet 99, this is typical operation" I am starting to think this is the case...

Absolutely not. When the system is clean and tight, your CIS system should start right up, every time. Buy, or better yet, build a test gauge. Armed with that, you can diagnose nearly all your problems w/out guessing or throwing parts at the problem.
Spend some time to get it sorted and you will be surprised at how solid these systems are.

John

I don't currently have a accumulator in the '79 GLi . I swapped to an '80 plastic gas tank and the old accumulator was crusty so I just bypassed it for the time being... It runs just fine, but it does suffer from hot start problem if its sat for more than 30 minutes but less than 1.5 hours after being run, but will still start after a few attempts.
I don't know quite where I was going with that other than the fact that probably ANY accumulator will work just fine, because with NONE it still isn't THAT bad..

When I ran my yellow car with the accumulator bypassed (it leaked something fierce) it ran fine. Only noticeable difference was the engine would start to cut out on sharp left-hand turns when I had less than 1/4 a tank of fuel.

That was with a metal tank with just the one center fuel pickup of course.