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Hey guys, Ricardo here. I've posted a few things on the issue I've been having with rough idling, car dying and about the new MAF I put in for my car that has been having issues with. I even reached out to the ECU repair place that I had my injector computers chip replaced and they said to clean off all grounds, that should do it.
So finally today the car won't go at all. Its to the point that I can't move it before it dies even before I put it gear.
What happens now is that the car starts and then starts to die. I'll press gas pedal to the point that the rpms are at 4,000 and I hold it there the whole time, but then about 4-6 seconds it starts to drop and then idles rough and then dies and the whole time I have my foot in the same position. I'll try it again and then when it starts to die I press on pedal a few times to get it back up in rpms but then I hear odd popping sounds inside engine. Like misfiring.
Where do I even begin to start tinkering with it? Is it the injector computer? I have a new MAF. New fuel filter. Maybe the pump is going bad? Please let me know.
I replaced it because it died on my completely. I sent it to ECU doctors in Miami. They put new chip in it and put it in and ran like new. Now that I've been having issues related to it again I reached out to Jorge who had helped me like 4 years ago and recommended cleaning all grounds. Which I did and now I'm where I'm at.
have you ever done an intake refresh?
What other maintenance have you done to car?
have you ever done a CE panel cleaning?
have you ever replaced the running relays?
Have you ever replaced the fuel pump fuse?
has the fuel pump ever been replaced?
do you have an intank pump?
Haven't done refresh. About in October I did the TB/WP along with new WP. Before then it had started with the high revving but it wasn't like bad in the sense that it would do it for days consistently. It would do it once then again like 3-4 weeks later it would do it. And what it would do was rev high after I would drive it for a while. And then so I would have a hard time leaving again because it would jerk back and forth and die before I could leave parking space. It's been worse with time.
Havent changed any fuses or relays. I have no idea where to start with that. What do I look for in a relay? I did change fuel filter a year ago. I recently took it off and cleaned out with compressed air. Put it back but still acting up.
Any think that you can recommend for me to read upon? As far as what you were asking about the fuel tank, what do I look for?
The computer work 4 years ago would seem irrelevant. Whether or not you now have an issue with the LH computer is a possibility along with the items Stan has listed.
For clarity - did you get a new MAF because of "this" problem [and it has not solved the issue] or did the problem start after you fitted the new [rebuilt?] MAF?
I decided to get a MAS/MAF from Louie Ott and I decided to get it because I was having those problems before I replaced it.
the one thing that keep turning my big red "!" every time is the "Tail" and it's working fine. That's the only thing that's odd from an electrical point of view and I guess not related to engine.
What relays and fuses should i look at? Or clean up? I'm lost, this is the biggest issue I've dealt with my 928 S4.
SRSLY from the info provided your putting bandaids on a failing set of parts.
You are now ready for an intake refresh,
NOTE dont cut corners,
replace all the electrical parts with Bosch.
Renew all the hoses and the pod and the flappy and throttle shaft bearings.
NOTE Roger has a complete list of parts its going to run about 4K,
that should include powder coating the intake and the cam covers.
Send the injectors out for cleaning or buy a newer set.
Replace all the fuel lines.
Replace the ignition wires and spark plugs and caps and rotors.
NOTE get the MAF rebuilt if not already done.
New Knock sensors, crank sensor and Hall sensor, new TPS, new ICV.
Please post pictures of the harness as this may also need to be replaced or new connectors installed,
replace the temp2 sensor and the temp sensor and the connectors
If you got the MAF from Louie then chances are that will be perfect.
Where are you located? Is there anyone close to you who could test your LH computer in their S4 or GTS? Given the outfit who worked on your LH seemingly have no "928 form" with this list chances are you will end up sending your LH to Louie either to test and more likely, to have rebuilt/exchanged.
Given the items Stan has listed, do you have any history to suggest any or all the items listed have been worked on? If those items are still those originally supplied [most unlikely] then they will all be falling apart and possibly non functional.
Also take a look at the connector to the MAF. The wires going into the plug are quite often falling to pieces [along with most other wires in the engine bay].
Take some pictures of the engine bay and post them.
The guys responding here are far more knowledgeable about the 928 than I am, but this sounds to me like it could be fuel pump related. When the car is off and the pump initially cycles, it puts enough fuel into the lubes for it to run for the 4-6 seconds, but isn't keeping up with the demand once the motor is running. First thing I'd do is create a jumper wire for the fuel pump relay that makes it run all the time. If that solved the issue, then it's the relay that's bad. If not, it could be the fuel pump itself, and you may have more than 1. Some cars have a low pressure in-tank pump that feeds the high pressure pump and others just have a filter in the tank and the high-pressure pump.
The fuel pump relay jumper I made when having a similar issue looked like this and I put a switch on it so I could turn it on and off when testing.
04-09-2017, 02:51 PM
Car Starts, But Dies Even When I Press Gas
