Thanks birdmanmt, treehunter and audiqv8,

Question:
have you replaced your fuel accumulator?

Answer: No, funny I'm not getting the suction noise when I remove my gas cap, is this related??

Question: Cold start injector? Can you test your fuel pressure?

Answer: No, I haven't tested my Cold Start Injector, how do you do it, just remove and stick in a Jar? I don't have tools to check pressure, anyone know where I can rent these tools?

Question:
When you changed the pump did you also replaced the check valve that screw onto the pump?

Answer: My fuel pump is a Brand new Pierburg, and from what I have read, the top check valve is not needed, they even supply a cap-nut as a replacement.



As for the car, when it runs it runs strong and hard, able to rev with not hesitations, one thing I do notice is that when it first stumbles to idle, there is black soot comming from tail pipe.

The car runs great actually and when I reach a stop, the car goes down to idle with no problems, and has lots of power, smooth rev up.

My fuel filter has a "shrader" valve that when I press, I can see fuel comming out, at times the pressure from the filter, out to the distributor is fast, good pressure, and other times it is less of a pressure. Sort of like when you take a hose and turn on the water, verse when the hose is on and you release a kink, more pressure.

Any suggestions, I know I'm almost there, and I want to get this puppy running, cause I plan to make it my daily driver.

LarryF_in_CA

remove the cold start injector, stick it in a jar then have someone crank the engine (ignition disabled) and see if anything comes out. should be a nice even spray.

have yet to experience hot start issues first hand but the lack of a check valve can't help matters.

under what conditions are you seeing these differences in pressure via the "shrader" valve?

did you notice any crud in the tank when you swapped fuel pumps?

treehunter,
I will work on testing the Cold Start Injector real soon.

The Pierburg fuel pumps have a built in check valve from what I understand.

I have checked the "shrader" during idle, and when the car refused to start. The pressure was high when the car was at idle, and the pressure was miminal when car refused to start.

I didn't notice any crud, only some black like glue stuff that is keeping the pump "holder" glued down to the bottom of the tank.

Thanks for your help.

LarryF_in_CA

Larry,

Just in case you haven't been there yet here is a link to SJM's troubleshooting page.

I've yet to have a hot start issue so I honestly can't help you from personal experience on that one. I do know there is a temp sensor in the head behind the power steering bracket that is connected to the whole "warm starting enrichment" hoo-ha. You can check there to see if it is getting any voltage and whether the sensor is toast.

Not to be devil's advocate but are you sure that fuel pump is getting full voltage? Do you still have the old pump handy? Maybe swapping check valves between the two could yield an interesting result. Is there any chance at all the pump is not seated properly inside the tank?

Then the previously mentioned fuel pressure accumulator, never had one go either but if you're going to fix this it'll mean going back to front a few times through the whole fuel system.

Be interesting to know if the car had issues when it was parked 5 years ago.

No chance of a vaccuum leak? Maybe you trashed an injector o-ring during the install?

I'll bet it's something simple, keep at it!<ul><li><a href="http://www.sjmautotechnik.com/trouble_shooting/ficis.html#fuelp">http://www.sjmautotechnik.com/trouble_shooting/ficis.html#fuelp</a</li></ul>

"Problem, it some times requires lots of cranking to get it to start when cold, and when hot it refuses to start."

Another area to check for hot starting problem is the crank position sensor. This is a magnetic sensor which reads a pin pressed into the flywheel. As the pin pass over the sensor it distrubs the magnetic field. This signal is used by the ECU to determine when the engine is approaching TDC. When the car refuse to start when hot do you still have a spark? If the answer is no then I would check this sensor, but if you still have a spark then I would look at the fuel system.

Good luck Larry it sounds as though you are very close to getting it to be a daily driver.

See my previous post on fuel pressure testing<ul><li><a href="http://forums.audiworld.com/v8/msgs/72510.phtml">Checking fuel pressure</a></li></ul>