Fuel Pressure Regulator

[JasonA]

Twice in the last 2-3 weeks, my SLS has been hard to start cold. It'll crank for about 5 seconds with no start. I'll turn the key off. Turn the key to "on", yep I hear the fuel pump, and crank again. It'll then sputter to life. This has happened twice in the last 2-3 weeks. All else, it starts just fine.

I noticed that on Rockauto.com, they list two FPRs from ACDelco...one is the "1st Design", for the nylon fuel rail, and the other is the "2nd Design", for the stainless fuel rail. The rail WAS replaced on my car as part of the recall, but I didn't know I got a new FPR as part of that. I figured they used the old one on the new one.

Does the stainless rail indeed take a different design FPR? I've put a seal kit on my (what I thought to be current) FPR, but haven't replaced it yet. But the way it sounds, it was new just a year and a half ago.

Short of a fuel pump going bad, does this symptom sound like an FPR maybe not holding FP in the fuel rail?

By the way, I'm taking the Caddy to the shop next week to get the A/C replaced. Will report back under appropriate thread.

Thanks,

Jason

[Mark Grek]

Jason I had the same problem less than a year ago, after a lot of research, it came down to either the fuel pump or deposits on the injectors. So I tested pump pressure and that was fine, so I filled with highest quality premium gas (Chevron with techron) and also some injector cleaner with techron. Then for a few weeks of everyday WOT,s it cleared up an all was well and still is. I highly doubt it to be FPR, since that would be on warm starts, had to change one myself several years ago. I think a few good WOT,s and a little techron may be worth a try.

Also when this was happening to me, I would turn the ignition on and wait about 30 seconds before cranking. This did the trick until deposits broke loose.

[JasonA]

Thanks Mark. I think I'm going to see if AutoZone still has their free rental program, and if they'll "rent" me a fuel pressure tester.

There are a few avenues to get to replacement of the FPR according to the service manual's flowcharts, but unfortunately, it's hard to say without actually using a fuel pressure gauge. I had a similar problem before...but it was a persistent hard start cold, but fine warm start. The problem was the lower o-ring seal on the FPR, allowing fuel to "leak back" and de-pressurizing the rail. It could be this problem again I suppose...or even an internal seal to the FPR gone bad.

Since this occured for the second time recently, I've been holding the key on for 3 seconds before cranking (the fuel pump will prime for 2 seconds on key-on) and haven't had the problem since...but it's only been a few starts. I have a feeling it's a fuel pressure problem. Just gotta find out why. I figure it's either the FPR or the pump. The FPR is only $40 from Rockauto.com, so it may not be worth much troubleshooting, the price is so reasonable.

I have been using only name-brand fuel, usually Amoco. We do not have any Chevron stations around here.

[Ranger]

Jason,

I agree, it is a fuel pressure problem and I'd lean towards the pump from what you say, but a pressure guage will tell the tale.

[JasonA]

Interestingly...the car starts VERY quickly now, after I got it back from the shop having A/C work done. The car didn't seem to be cranking slow before, but I'm thinking maybe it was a slightly loose battery connection. It fires up VERY fast now. And they DID disconnect the battery during the A/C job.