09-15-2001, 09:04 AM
What exactly is the use of the fuel pump relay? If it was bad, would it cause hard starting when cold? I've been trying to read up on it with the Bentley...but I'm just dumb.
It has a place on top for a fuse, which I guess is used in diagnosis. The book says numbers will pop up? Is this only on a mechanics computer or is it on a dash? OKay, so I put a fuse in it, and when I left it in there for more then 4 seconds, I could hear what I guess is my fuel pump start to run (or hum) but not too loud.
A mechanic told me the fuel pump seemed to be fine, but the fuel pressure regulator (accumulator) (damper) might be the culprit (which makes sense). Everything in the car runs fine while driving and warmed up, and theres no real rough idling when started from cold, just it takes 3-5 seconds of cranking before it turns over. Then all is fine. And if i turn it off, then back on, it starts right up.
My interest in the relay is because of Audifans trying to figure things out.
87 5000 cs turbo 2.2 auto
09-15-2001, 06:05 PM
Okay, if your mechanic says the pump is okay and he has NOT put pressure gauges on the system, then he is guessing and taking your money, which is bad because wallets have a definite bottom to them - unless you are Bill Gates. Heck, I'll guess and take your money, but since we are birds of a feather (both drive 5k's), I'll try to help you out.
First, for the instructions on code dumping, go to the link below.
Second, go to the bookseller of your choice and buy 'Bosch Fuel Injection and Engine Management' by Charles Probst. This is a great book, and explains in detail how your fuel injection system works. It's written in language that a shade tree mechanic can understand, I bought my copy at the Bentley tent at Road Atlanta last year and it is a terrific resource. I've used it a number of times to diagnose things.
Having said all that, it sounds like your car is just like mine - old, and probably has leaky injectors. If you have leaky injectors, the residual pressure leaks down overnight and your lines to the injectors lose pressure because the injectors are leaking gas from the tips. When you crank the car in the morning, the fuel pump has to work to pump up the lines to the injectors, and it takes a few seconds, then it stumbles to life, then smooths out. Drivability is fine (since they aren't completely gone) but if you were to pull them and check the spray pattern, it would probably look like, well, something along the lines of a toddler peeing into the toilet. Not the fine mist of atomized gas that it should have. When you restart, the lines are already pumped up and ready to go, hence the quick start.
During the summer, I have to crank my 5ktq sedan for about 5 seconds, then 3 cylinders fire off, then four, then the cranky 5th one chimes in. I have not had the time or inclination to pull the injectors since I had other battles to fight - steering racks, brakes, tires, afterrun pumps, bad fuel pump relays, blower motors, accordion splices, heater cores, etc. - but I will get around to it one day. And as soon as my buddies at Autobahn Performance here in Atlanta have a sale on injectors, I will be the first in line.
But my gut says you have leaky injectors.
Buy the Probst book first. Then, have your mechanic put a pressure gauge on the fuel distributor and see what the pressure bleeds down to after sitting for a while (the time and the pressure reading are in the Bentley, which I don't have handy right now.) And if your mechanic doesn't have a pressure gauge, find a mechanic that does.
Let us know what you find out, and good luck.
87 5kcstqw<ul><li><a href="http://forums.audiworld.com/v8/msgs/161.phtml">http://forums.audiworld.com/v8/msgs/161.phtml</a</li></ul>
09-16-2001, 08:16 AM
Thanks Steve. I will do everything you said and letcha know what happens. But, like you.. time has a bottom, like my wallet too, so I don't know when I can get to all this. But You've given me the most detailed list of checks so far and I'd be a fool to ignore you. Thanks again.
09-16-2001, 03:07 PM
And I think I will do the fuel injection first... since it seems very logical and...
I took out each spark plug and found one that still smelled like gas and was wet after the car sat for 2 hours. I checked for codes BTW and the system spewed out 4444 which is ok.
So.. I have a wet, gas smelling plug, and also a wet cylinder (the other piston tops looked dry when I shined a flashlight down there). I only tested 3 plugs but I got excited cuz I was making a breakthrough :)
If I were to order new injectors.. am I supposed to order gaskets or o-rings seperately? Is there anything else that is usually replaced along with injectors to make the system complete and happy? Advance Auto quoted me 90 bux per injector, but I've seen them for as cheap as 42 and I have one more quote coming via email soon.
Will continue to keep you informed if you want....
02-16-2004, 12:03 PM
can any one tell me how to remove an injector form my 86 cgt