hiljak Posted August 20, 2004 Report Share Posted August 20, 2004 As some of you may know, I was having a problem with a small stumble in my 99 sts which I thought may have been related to the FPR (changed the plug wires already and cleaned the throttle blade). I decided to swap the FPR from my 95 and see if the problem would go a way. Well in the process, I ended up pinching a wire for the idle control (what a nightmare) but I fixed that. Now, my car runs and idles as it used to, but when I go to start it, it cranks for much longer that it ever used to (it used to start up almot instantly). Could this be related to the FPR? I get no gas from the nipple while its running but isn't this symptom in line with FPR problems? Any way to further test it other than the nipple test? Thanks. James 1999 STS 65k 1995 STS 127k Link to comment Share on other sites More sharing options...
KHE Posted August 20, 2004 Report Share Posted August 20, 2004 There is a small o-ring where the FPR connects with the fuel rail - probably 3/16" in diameter. If that got lost, it would cause hard starting. It is very easy to lose that o-ring if you don't know that it is there. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
hiljak Posted August 20, 2004 Author Report Share Posted August 20, 2004 KHE, Thanks for the reply, I will check it tonight and report back. James 1999 STS 65k 1995 STS 127k Link to comment Share on other sites More sharing options...
Dan K Posted August 21, 2004 Report Share Posted August 21, 2004 I recently had a similiar problem with my FPR. My cadillac told me that 98 and up FPRs are different than 97 and lower. So if the "O" ring isn't the problem, this might be a consideration. Good luck......Dan Link to comment Share on other sites More sharing options...
hiljak Posted August 21, 2004 Author Report Share Posted August 21, 2004 Well, I the lower oring was just sitting in the bottom bowel (not in the inner center of the bowl where it should be). I put the top of the FPR together with ring support, large o-ring, screen, then small o-ring then inserted the whole thing in to the bowl. It appears to start fine now. Thanks for the help. Dan, I thaught I read the FPR's were the same for the 1995 to 1999. Can anyone verify this? Logan, Guru? I still, however, have the friggin' stumble in the idle. Am I nuts, or should a 99 STS idle with no stubles, especially no stumbles big enough to watch on the RPM needle. Would the idle learn procedure have anything to doo with stumbling? I am open to any sugestions. James 1999 STS 65k 1995 STS 127k Link to comment Share on other sites More sharing options...
hiljak Posted August 21, 2004 Author Report Share Posted August 21, 2004 Well, I'm reading in the manual and it says to check for propper routing of the plug wires as to prevent arcing. I'll admit that when I changed them, I couldn't remember the exact route they traveled in. Obivously, each cylinder is connected to the correct coil, I am talking about the specific placement of each cable in the retaining clips. Could this have something to do with it? I can't seem to find a picture in the manual that clearly shows the routing. If anyone finds one, please post it. Thanks. James 1999 STS 65k 1995 STS 127k Link to comment Share on other sites More sharing options...
hiljak Posted August 21, 2004 Author Report Share Posted August 21, 2004 I've found a diagnostic chart for rough idle and there is a step which says to "Observe Long Term FT" for lean or rich condition. how is this done, do I need a scan tool? If so, are there any decent ones that are reasonably priced? James 1999 STS 65k 1995 STS 127k Link to comment Share on other sites More sharing options...
bigfoo Posted August 21, 2004 Report Share Posted August 21, 2004 Yea you gotta have a scan tool to watch fuel trim.. I have yet to get one for my car.. I really want one My 99 doesn't and hasn't ever started instantly.. it cranks over probably 3 times and then starts, every time. My hot rod mustang I build would start so fast you could almost just flick it into the start position and it would BOOM to life instantly hehe.. Really i'd rather have it crank a few times before starting though. Mine alos has a stumble in the idle.. it's always has it.. it's almost unnoticable but you can feel it, I tried replacing the plugs, wires, and several other things and nothing 'fixed' it.. I don't think it's a problem though. I want a scan tool to check the FT and the missfire count. I suppose it could be a problem with the ignition module or a coil pack :/ Link to comment Share on other sites More sharing options...
hiljak Posted August 21, 2004 Author Report Share Posted August 21, 2004 Bigfoo, If yours is hard starting, take the FPR apart and make sure that smallest o-ring is intact and where its supposed to be. That fixed my hard starts. Now its on to the idle stumble. James 1999 STS 65k 1995 STS 127k Link to comment Share on other sites More sharing options...
Dan K Posted August 21, 2004 Report Share Posted August 21, 2004 cadillac told me that the FPRs look the same but are different for 98 and up. Also, I believe the injectors are different. I would bet the flow rate and operating pressure is slightly different between the two. They might work for each other but not perfectly........Dan Link to comment Share on other sites More sharing options...
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