i noticed for the past week that when i am driving after the car warms up for about 15 minutes, it bogs down really bad then it dies. i try to start it, but it just rotates. when i unplug the relay under the dash and try to start it, it starts, then dies. i plug it back in, then it starts right up and runs normal again.

things i have replaced:

fuel pump
fuel pump solenoid resistor
fuel relay under the dash
plugs and wires

things i have checked:

pressure regulator (works fine)
fuel pressure (fine)

if i had to make an educated guess, i would have to say that either the fuel injectors need to be remanned, or the main relay is going out in it.

 

Not sure why you think the Main relay might be at fault but you can easily bypass it by disconnecting the four wire plug to it and jumpering the White/Red wire to the Black/Yellow wire and the White/Blue wire to the Black/White wire. Doing this though will supply a number of different components in the car with constant voltage which might drain the battery.

 

well, i have had this problem before but not just when it warms up. i replaced the relay and all was well. what it is doing is either flooding itself with too much fuel at certain rpms or drying itself out with not enough gas at certain rpms. i think i will try to replace the main relay and also the pressure sensor to see if that will solve the problem.

 

Does the stalling occur at any rpm or just at close to idle speed?

The Main relay has a ground wire which could cause it to cut out when it feels like it if the ground connection is a poor one. Bypassing the Main relay as suggested is easy and removing one side of the jumper would prevent any possible battery drain. The jumpering is just to tell you whether or not the relay is the problematic cause or not and the jumpering also prevents the relay ground from being a possible factor.

Have you checked the connection to the AFM to see if all is well there? A glitch in the AFM could definitely cause your problem. If the Brown wire that eventually leads to the Circuit Opening relay is poor that could also lead to your problem in addition to a poor connection to the fuel pump.

Next time your problem occurs it would tell you a lot if you used a multimeter on the fuel system wiring w/o turning the key off to help narrow down the actual cause.

 

well, today i changed out the leading and trailing coils, main relay, and pressure sensor. i dont know if that helped it at all because it seems like it still runs the same as it did. so the next step i took was to inspect the air filter(aftermarket aem cone) and the mass air flow meter. when i took off the filter i couldnt see through it at all. so, i took an airhose to it and a crapload of dirt and dust came off of it. then i sprayed it down with brake cleaner to remove any other deposits and the brake cleaner was sorta brown. then i used the brake cleaner to completely douse down the m.a.f. let it all dry, put it back together and i didnt have any problem with the car stalling or flooding since i drove it today. maybe i should get another air filter and see if that corrects the problem if it so happens to stall on me again.

 

i have the same problem, i thot it was the AFM??

 

I had the same exact problem! I stared my 7 last night, it warmed up, stalled, I cranked it and it just spun. So I flipped my fuel cut off switch cranked it, waited a minute or two talking about what to do with my friends, then next crank started like nothing ever happened. Then it died again when the revs dropped to idle and I couldnt get it started this time. So we push started it and I drove home. This time it didn't die out at idle even at lights. BUT the only problem is I just cleaned and re-oiled my filter... maybe it was over oiled? ill try cleaning/reoiling the filter AND cleaning the AFM to see it works.

P.S whoa this thread is oldish? I was reading the dates wrong, the way they are read on Japanese expiration dates. year,month,day... and i also notice if that were correct I would be the worlds first time traveler... LOL'D Hey at least Im using the advanced search!

 

how do you bypass the main relay?

 

B/Y is jumpered to the W/R wire and the B/W wire is jumpered to W/L. All these wires are found in the same plug.

 

so when i do this, i can leave it like this and it wont hurt or drain anything? key off = power off and key on=power on same as stock setup?

 

Jumpering will drain the battery w/key to off.

 

well then what is the point?

 

You asked.

 

i understand, but i mean, what is the point of jumpering it if it will drain the battery? wouldnt it be more sufficient to just get a good working main relay instead?

 

nevermind......i re read your post to my question about how to jumper the relay and now i understand that this is just a testing procedure.

it would be nice if there was a way to eliminate the main relay completely to where it would not cause any draining issues with the battery.....hmmm

 

There's only two ways for the Main Relay to drain power. One cause would be if either of the two relay contacts inside the relay are stuck in the relay position or the B/W wire in the two wire plug had constant voltage on it. Under either condition, either the B/Y wire and or the B/W wire in the four wire plug at the relay would have voltage on it with the key in the off position. If this condition doesn't exist then the Main Relay could not be the source of any battery drain.

 

i think the black and yellow wires goes to the coils...you could bypass it just for now to see if that solves the problem, if so then just replace the relay with a new one...

 

i really dont think the main relay is the problem. i have 3 of them, and one of which is brand new which is on the car now.

i went out to try to turn the engine over and my battery is completely dead after just 2 days. what are the main sources of a battery drain? sensors, grounds, etc. and where should i start looking first? i am going to reground everything to a grounding block but i think that i should find the source of the problem first to see if there are any major failures causing this to happen. this could be my main problem of why my car is stalling under any condition.

 

Hailers suggested you measure for a voltage drain by disconnecting the negative battery terminal and place one meter terminal to the negative battery cable and the other to the battery terminal w/the meter set to read amps and the doors closed w/no key needed for testing. There are usually two settings on the meter and choose the DC10A setting and see if there is a drain of more than "50 milliamps." If you do this test after the car has been running, wait for thirty minutes to allow the electrical circuits to completely shut down. Make sure the doors are closed and no key is needed for testing. If the amperage drain is large then disconnect the voltage wires to the alternator and take the test once again.

 

It could be a bad thermosensor.

When I bought my 7 from the PO, it would die after warming up. It would only start again after cooling down.

Asked him to try a new thermosensor and it ran great!

He replaced a lot of stuff.

 

i have 2 new thermo sensors.............been there done that.