Anyone in Michigan with OB CIS knowledge?

well it will idle (as long as I don't touch the throttle), but I have no throttle response...on to checking more for vacuum leaks and the like. If I give it even a little throttle it will kill the car...this is difficult without a good set of gauges, I may have to wait until I get them from 928sRus. Who knows...I guess it could also need to run through until it gets some good fuel, but I had it idle in the drive for about 10 minutes with no real issues to get warm.

Thanks for the help

Josh

he_mech_usmc;7305 wrote: well it will idle (as long as I don't touch the throttle), but I have no throttle response...on to checking more for vacuum leaks and the like. If I give it even a little throttle it will kill the car...this is difficult without a good set of gauges, I may have to wait until I get them from 928sRus. Who knows...I guess it could also need to run through until it gets some good fuel, but I had it idle in the drive for about 10 minutes with no real issues to get warm.

Thanks for the help

Josh

I hate hunting for vacuum leaks on 928s with all of their varieties of lines and hoses and such. The only ones that leak are the ones that require you to tear down the whole intake to replace, seemingly. And if it's accessible, then Porsche no longer makes the particular hose that you need.

I wish they produced intake refresh kits for our earlier 928s like they do the later models.

ick, hope it isn't fuel distributor. Or the brake booster, speaking of vaccuum- good pedal?
I might change the sytem pressure regulator in the FD as a precaution too, but I'm prone to changing things in advance of a solid diagnosis- not the best approach in most respects.

I've only been here 2 years but I don't think I have heard of a bad fuel distributor. Brake booster maybe once. The problem is, the more you change the harder it gets to diagnose the problem, so try not to change to much, just try to verife each system.

In post #6 you said

he_mech_usmc;7227 wrote: Got home last night with no CIS gauges, held the FP relay to build pressure, car fired and I let go of the relay...relay stayed engaged and the car ran for approx 2 min, but when I lost pressure the car died...just wondering if the 044 pump may cure this...no visible leaks, and I can't smell fuel leaking anywhere so I don't know what is causing the loss of pressure, could be the cheap pump...got the CIS gauges on the way...didn't know if anyone had a spare 044 pump that I could get them to part with to try while I wait.

Thanks,
Josh

I want to know what you mean by holding the FP relay

Also, did you remove and clean the screen?

Brad

Fuel distributors are pretty vulnerable to problems from sitting. The rubber seals inside can react with some fuel and particularly some fuel additives, and the plunger itself can get hung up via silt corrosion, debris from degraded parts.

If it ran for close to two minutes, that should be far longer than the cold start valve would support with its initial squirt, so that's good.

I agree that the relay still sounds odd- does it have a reset switch physically on the relay (in a non-oem fashion)? Still don't think that's the root problem, if it is passing fuel sufficient to idle, but doesn't richen up in response to throttle movement..have you pulled the air cleaner off and tried to depress or watch the air metering plate, or are you just using the linkage on the throttle body?

it seems that the FD is good at this point, but I think there may be some crap inside. The air metering plate has some pressure on it after the car is shut down so it appears that it is holding pressure in the FD as it should, I have been doing all of the testing on my own so it has been a little hard to get to some of the components. The car would not stay running without the air filter on, but as soon as I put it on it will sit and idle until I shut the car off or attempt to give it some throttle. It's outside and we have 30 deg temps so as soon as I get a hankering to get cold I'll go out and pull all of the injector lines and injectors and clean them out...so in reference to the throttle question I guess yes, I am only relying on the cable to the throttle body. Again, the relay is working as it should, before I found the mesh screen in the FD plugged I had to hold it to "over pressure" the FD intake port to allow fuel through. When the car is Idling it stays engaged and when the car is off it resets as it should.

Thanks,
Josh