SYS light fixed!
Thread Starter
Burning Brakes
Joined: Jul 2003
Posts: 873
Likes: 2
From: Whittier ca
SYS light fixed!
After reading all the posts I could find on CF, especially C4Guru’s page on pulling the codes from the CCM (thanks Andy!), tearing the dash apart, checking grounds, etc, etc, I ended up taking my 91 to J&D Corvette in Bellflower. Turns out the ECM lost the ability to communicate, not the CCM. Strange thing was that with the scan tool they used, the tech could get to the ECM and get information. Back door, I guess. Changed my prom to a new ECM and no more SYS.
They also told me the FPR was leaking. WTF! I had just replaced the diaphragm the first of December. So – off to get another. After installing, I did not get the chance to do a running pressure test but the leak down test was good. Drove to work and back home and hooked up the FP gage. Key on pressure – 41#, drop to 39# - 10 minutes down to 36#. Engine running pressure – 66#’s!!! Disconnected the return line at the fuel rail and blew air to the tank (if you do this, crack the gas cap a little – don’t ask how I know). No blockage. Off with the plenum and back to the FPR. I decided to remove the regulator, not just the cap, to check the diaphragm. When finally apart, the port to the return line was plugged solid with some black, grey, white kinda cr-p. I checked the return line and found a rock hard deposit blocking the return line solid for about ¾”, which looked like the build up in a coffee maker. If I had to guess, coulda be sugar, but the injectors and everything else seems ok (new fuel filter in November). After cleaning with hand driven drill bits and some de-natured alcohol and flushing with a carb. Cleaner, FP is: Key on 39#’s, leak down – 30 minutes 39#’s to 35 ½#’s, running – 38#-38 ½ #’s constant
All that said, to anyone interested, it would be a good idea to check the return lines and pull a running FP test every so often.
Good luck
Subman
They also told me the FPR was leaking. WTF! I had just replaced the diaphragm the first of December. So – off to get another. After installing, I did not get the chance to do a running pressure test but the leak down test was good. Drove to work and back home and hooked up the FP gage. Key on pressure – 41#, drop to 39# - 10 minutes down to 36#. Engine running pressure – 66#’s!!! Disconnected the return line at the fuel rail and blew air to the tank (if you do this, crack the gas cap a little – don’t ask how I know). No blockage. Off with the plenum and back to the FPR. I decided to remove the regulator, not just the cap, to check the diaphragm. When finally apart, the port to the return line was plugged solid with some black, grey, white kinda cr-p. I checked the return line and found a rock hard deposit blocking the return line solid for about ¾”, which looked like the build up in a coffee maker. If I had to guess, coulda be sugar, but the injectors and everything else seems ok (new fuel filter in November). After cleaning with hand driven drill bits and some de-natured alcohol and flushing with a carb. Cleaner, FP is: Key on 39#’s, leak down – 30 minutes 39#’s to 35 ½#’s, running – 38#-38 ½ #’s constant
All that said, to anyone interested, it would be a good idea to check the return lines and pull a running FP test every so often.
Good luck
Subman
Safety Car
Joined: May 2005
Posts: 4,176
Likes: 7
From: Jennings LA
[QUOTE=subman;1558507812 I checked the return line and found a rock hard deposit blocking the return line solid for about ¾”, which looked like the build up in a coffee maker. If I had to guess, coulda be sugar, Subman[/QUOTE]
why sugar you pi$$ed someone off latley? by the way I fixed a mustang someone did that to.it was not pretty. ruined the motor twice, the first replacement went out in 30 minutes. we had no idea there was sugar in the tank. needles to say his insurance company had a huge bill.
why sugar you pi$$ed someone off latley? by the way I fixed a mustang someone did that to.it was not pretty. ruined the motor twice, the first replacement went out in 30 minutes. we had no idea there was sugar in the tank. needles to say his insurance company had a huge bill.
