Daniel5691

Roger is off the hook!
I think he has a time machine.
Whenever I order parts, I swear he must be shipping them by SR71 Blackbird delivery ha ha.
Too fast !
Thanks Sir Roger.

GT6ixer

Speaking of time machines...where have YOU been!

jpitman2

You know how crowds chant things - "what do we want?" - anything you can think of- "when do we want it?" NOW!!!

Well....



What do we want ?

A Time Machine!

When do we want it ?

Irrelevant !

jp 83 Euro S AT 57k

ROG100

Thanks - you are most welcome.
I have been in FB jail.

928w2b

Hey Roger, Tony here. You've been a great help to me in the past with parts and answers. Got a question for ya. My car is an 81 Euro, but my engine number is M28/22. I believe everything on the top end is for 81. What is the correct fuel pump for my setup, I think I bought the wrong pump. Car is running rough now and won't stay running.
Thanks

jpitman2

Tony, You dont say which injection system you have, which would help determine which pump is correct - CIS/K-jet, or L or LH type. Without a pressure reading and a delivery rate value, you wont know if your pump is the problem. However, I believe the pump type is close to irrelevant - my car is CIS, running system pressure of ~75psi, delivery of 1350cc/30 secs. When I got the car it had a later S4 (LH injection) type pump fitted, and this worked fine in temps up to 120F. My theory is that any modern fuel injection pump that will fit the plumbing will do the job.
CIS can be picked by having hard steel pipes running to each injector, with no electrical wiring involved. If you dont have these, you are L- or LH- injection which will run ~45psi, but similar delivery volume.
jp 83 Euro S AT 57k

928w2b

jpitman2, thanks for the response. My injection system is CIS/K-jet. I'm a novice, I need to get pressure gauges and figure out how to use them. I'm not sure the pump is the problem, will the gauges help me narrow down the issue? The car won't stay running, so will the gauges matter?

jpitman2

It will help if you can describe the way the car starts and runs and stops in detail. If it starts ok then gradually chokes and dies, probably staying rich, not leaning out - WUR problem, control not rising with temp.
With CIS the usual problems are correct pressures and rubbish in the system. A gauge set will give you much info on where the problem is likely to be. You can easily do a delivery rate test now - Disconnect the return hose at the right side cam cover (I think its the rearmost hose), connect a length of hose to the engine side of the connection, run it into a say 2litre bottle; fit a relay bypass to the fuel pump relay socket, power it for 30 secs. Have an extinguisher handy! You should get ~ 1350cc. A pump relay bypass I use is a length of 2 core flex with a male 1/4" spade tag on both wires at one end, and a momentary switch at the other (only closed when held down). Make the wire long enough to reach around to the front of the car so you can see if anything is leaking.
With gauges - my preferred book on CIS is Ben Watson on Bosch injection systems - very good on trouble shooting, and how to connect gauges - do a search here and generally on the web for connections. Basically, valve closed, pump running, gauge shows system pressure- 65-75psi; valve open gauge shows control pressure. Cold control can be a s low as 20psi - this is back pressure produced by the Warm Up Regulator (WUR), controls mixture richness. High cold pressure will make cold starts difficult; high warm control will severley limit power - this should peak at ~45psi fully hot. If you have high cold control, first suspect is blocked WUR. To verify this, crack open the outlet of the WUR a little (with rags and extinguisher handy) - if the pressure goes down and fuel flows out, WUR is probably OK, blockage is further down the line - follow the pipe, opening unions - when one does NOT flow fuel and lower pressure, the problem is the pipe between this union and the previous. Its even possible to be in the return line to the tank. If the WUR is blocked (little fuel flows out when outlet cracked open, pressure stays high), you need to research how to open it and clean it - there are brass gauze filters inside, very small holes etc. The filters can clog with lint, dried fuel residues due to standing for long periods etc. Try forcing carb or brake cleaner backwards through it with a syringe into the outlet, to force stuff out the inlet.
I think Roger carries gauge kits. There is some good stuff here https://rennlist.com/forums/928-foru...-pressure.html and some videos on the connections. I have had good results with loading the tank with Berrymans (more than usual) or similar, and jumpering the pump and letting it run for long periods to flush out rubbish in the lines and dump it in the filter. Once you get it to run stably you can consider problems with injectors - people who work on older 911s can probably test, clean and diagnose the injectors. Brass MB injectors, despite being shorter than ours, seem to work fine, and are cheap-ish and available.
hth
jp 83 Euro S AT 57k

928w2b

Wow, great info. The car starts up fine and then gradually chokes and dies. You guys are a wealth of knowledge. This is a great start for me, much appreciated.

jpitman2

Electrical problems - relays, relays, relays.
CIS problems - pressures, pressures, pressures!
Sounds like its staying rich and choking as it warms - is exhaust sooty , or smell of gas?. Either WUR control pressure is staying low, or the cold start injector stays firing - can be caused by the thermotime switch failing to open - front of waterbridge, horizontal fitting.
jp 83 Euro S AT 57k

928w2b

Fuse panel has been cleaned with all new fuses and relays. Exhaust is a little sooty with gas smell.

928w2b

jpitman2, I will be replacing the injectors with the MB short ones. I assume that I can use the OEM seals and sleeves with them?

jpitman2

Yes, the top end is identical for the -012 and -047 units. Getting the injectors out can be a PITA. The WSM shows a lever type tool to get the injector out, but IIRC I used a deep socket on the hex section to unscrew the alloy part that holds the rubber with the injector into the inlet tract. These alloy parts are light and fragile, so take care. Lubrication is good. The new rubbers/seals will be a little easier to fit, but still not fun.
Try here - just over $20 each! The -012 can be seen near $75 each.
These might be the rubber seals.. jp 83 Euro S AT 57k

928w2b

Thanks JP, I took one of the of the injectors out earlier this evening. The injector came out easily, but I already bent the sleeve getting out the seal, didn't realize it was aluminum I'm going to take your advice and start with the WUR and injectors, just need to get some oem seals and a replacement sleeve now. Looks like my car has a fuel pressure damper, think I should just replace it also?

928w2b

I already had bookmarked the injectors and seals from Amazon before I reached out to you, just wasn't sure the little tip on the seal was correct.