: '97 etc flooded after hot soak



tateos
08-10-10, 09:15 PM
Lately, if/when I try to start my car after it's been running for awhile, but before it has had a chance to cool down completely, it will act like it's flooded - hard to start, backfires sometimes. If I open the throttle a little, that seems to help. I think one or more of the injectors must be leaking down, right? How do I know which one? Or should I be looking in a different direction? BTW, cold starts and all other engine operation is great - even fuel economy is excellent - 25-26 MPG back and forth to work, mostly highway

Jailtime
08-10-10, 10:09 PM
My 96 SLS did that and it turned out to be the fuel pressure regulator.

Ranger
08-11-10, 12:10 AM
Yeah, check the FPR first. Far more likely than an injector.

tateos
08-11-10, 09:20 PM
OK - will do - I knew about that, and had planned to check it, but didn't think that it gave that symptom. So the diaphragm leaks, and the fuel leaks into the vacuum line and into the intake and then floods out the engine? Interesting.

Ranger
08-12-10, 12:23 AM
Well, it makes for a rich start which causes a hard hot start. Not sure exactly how much fuel would actually leak and if it would be enough to actually "flood" the engine.

tateos
08-12-10, 02:55 PM
When I say "flooded", I mean it acts like an old school carbureted car on which the needle and seat are leaking a little, so yes, it is too rich when trying start, but only after a hot soak. Stepping on the gas a little before turning the key to start allows some extra air in and help the engine clear and start. I suspect that when the engine is cold, the little extra bit of fuel (that I suspect is present) is not sufficient to cause anything noticeable, and it starts and runs normally with no additional throttle needed.

Ranger
08-12-10, 05:11 PM
Sure sounds like a leaky FPR to me Tateos.

tateos
08-13-10, 02:26 PM
I'll check it out this weekend and report back what I find. I checked online and that FPR is kind of pricey - looks to be around $50 on Rock Auto.

Ranger
08-13-10, 11:36 PM
Get the part number from Rockauto and plug it in at Amazon.com. I just got an AIR pump from them. Rockauto wanted $162 shipped. I got it at Amazon for $122 with FREE shipping. Not sure if the FPR will qualify for free shipping though.

tateos
08-14-10, 08:33 PM
Update - last night, I pulled the beauty cover and then the vacuum line for the FPR - nothing. Then I monkeyed around with it - rotated it while installed - all of a sudden, hot fuel squirted out of the vacuum nipple! I relieved the system pressure at the schrader valve, then removed the clip and valve - the screen remained on the cup on the fuel rail. I hooked up a vacuum pump to the nipple and it seemed to hold vacuum, then all of a sudden I heard a sound coming form the engine and when I looked, I could see that the FPR screen that I had left in the fuel rail had somehow been blown out there by hot fuel pressure or something - it was still barely visible - under the intake manifold. One attempt with a claw tool later, and it was gone forever, or at least until the next time someone else or I remove the intake manifold. I ordered a new FPR from Rock Auto today - I did check Amazon, Ranger, and it was about the same cost - $1 more I think, but thanks for the suggestion. I'll let everyone knwo what happens when I get the new FPR installed.

RM

Richard Moore

tateos
08-26-10, 01:45 PM
UPDATE - got the new FPR from Rock Auto - about $50 delivered - still seems like kind of a lot to me for the little P.O.C. that it is. It took 2 days to get to Phoenix with standard shipping (that Rock Auto is really good!). Installed it on Tuesday night - no more problems starting, hot or cold, since. So far, so good.

Thanks for the advice all!