Fuel related problems...

[82Stang]

Hello,

1999 Buick Park Ave 3.8L non supercharged 8th digit vin K

Car has been not starting in the morning or when sitting for an extended period of time. Scanned for codes, nothing. It always runs flawless except the last few weeks, it has been pulling this crap intermittently. Every morning this week, it won't start unless you keep trying it for 5-10 mins. Pushing accelerator pedal a couple times.

I put in platinum+2 plugs and new wires, due for tune anyway. Got my fuel pressure guage on it and it said:

KOEO - 42psi
then slowly falling and after a few mins down to 30psi

KOER - 40psi

I went by the book/manual and followed the tests. Unplugged vacuum from fuel pressure regulator (while running) and the pressure jumped up to 48psi and held steady. Manual said if it jumped up in pressure, to check/replace regulator. I did, no change. What I did was leave the vacuum off the regulator and plug both sides for now so it will run in the morning, hopefully.

1) Is it ok to leave that unplugged?
2) Does this mean the pump is bad?

Thanks, I appreciate the help.

[maxwedge]

Don't leave the hose if you will have a rich mixture, not the answer. Scan it and look at coolant temp sensor inputs cold, clean the iac and throttle body, replace the fuel filter also, just general areas to look at for your condition. Press. is a little low, but that could be gage accuracy also. 47 is about right, hose on, try another gage to confirm.

[82Stang]

Originally Posted by maxwedge

Don't leave the hose if you will have a rich mixture, not the answer. Scan it and look at coolant temp sensor inputs cold, clean the iac and throttle body, replace the fuel filter also, just general areas to look at for your condition. Press. is a little low, but that could be gage accuracy also. 47 is about right, hose on, try another gage to confirm.

I have no problem checking the things you mention, the easy ones. Thing is, when I did the KOEO test it went to 42psi, then went steadily down within 2 mins to 30psi. With that leakdown, could it be anything other than the fuel pump? KOER was actually 47.5psi, but I rounded there.

[Jrs3800]

It could be a bad Pump, Bad Pressure regulator( just because the pressure jumped up with the Vac disconnected doesn't mean the FPR isn't bypassing fuel back to the tank..)... Could even be a leaky injector..

Also how many miles do the Bosch Plats have on them? And I will tell you to never use them again on any GM with a DIS system..

[82Stang]

Originally Posted by Jrs3800

It could be a bad Pump, Bad Pressure regulator( just because the pressure jumped up with the Vac disconnected doesn't mean the FPR isn't bypassing fuel back to the tank..)... Could even be a leaky injector..

Also how many miles do the Bosch Plats have on them? And I will tell you to never use them again on any GM with a DIS system..

I'm not a fan of Bosch anything, but the wife came home with them the other day so I replaced with them. It had AC Delco +2 in there. Apparently these are supposed to be better, but I'm not real confident about that. Anyway, they are in. Generally, AC Delco for GM, Autolite for Ford and Champion for Dodge, but...

I tuned the car up and replaced the FPR, so that's new. She had trouble again today starting up to leave work. My fuel pressure readings are the same regardless of the new FPR. Just that it jumps up when the vacuum is removed. Talked with Gm dealership here and they said I could try a fuel filter, but that it was probably the pump. So, I'll get the fuel filter anyway, normal tune up items. I'm getting a used pump tomorrow($100) because we just don't have $400 for a new one. She said get that one and I will(90 day warranty). All this labor is not costing anything cause it's me so we can do it this way.

Lucky for me, it has an access in the trunk. Funny thing though. About 5-7 years ago, a year or so after we bought this car from that dealership, I had to bring it back in and they replaced the fuel pump. In the process I waited and watched as this young tech (prob $7/hr) was trying in vain to get it out the access. I walked over and asked him how it was going. He said he couldn't get it out and that he'd have to drop the tank. LOL. I put the brakes on that right there and told him, naah, it'll come out this way, as I got in to try. It came out that way and I was just perplexed at the shit dealers give you. Servicewise and partswise. I knew more than this kid, but it was under warranty so heck, let them right? What I'd like to know now is why there has been atleast one, maybe two fuel pumps put in this thing since birth? I'm about to install the 3rd.

[maxwedge]

Fuel pumps in general are not an issue with this car, I don't think this is your problem.

[82Stang]

Originally Posted by maxwedge

Fuel pumps in general are not an issue with this car, I don't think this is your problem.

Just came in for a minute to wash up and check the mail. I have the plenum off right now and it is wet on the injector side, not the regulator side. I pulled on the injector hoses and two of them on that side pulled right up. So I plugged them back in and am going to change the regulator anyway since I'm there. I'll let you know what happens.

P.S. Max, I hope your right...

[HotZ28]

Hook it up to a scanner and read the engine temp when trying to start engine when cold; as suggested in post #2.

[82Stang]

Originally Posted by HotZ28

Hook it up to a scanner and read the engine temp when trying to start engine when cold; as suggested in post #2.

The scanner I have is a plain jane read the codes sort of thing. After replacing the FPR, it seems to run much better, but it is stalling out way bad and the battery is dead. I keep jumping it with my other car and let it runa min or two, but it still goes dead. Also I had the O2 sensor underneath, broken off and not fixed yet. It is nothing, but a nut on the hole now. Sealed, but not right. I have another one, but can't get that sucker out. I'm guessing that is my problem now. That and a dead battery. It was running better, but still alittle bit off. It ran good at high rpm, but not so stable at low. If I let off the gas, it might stall and then I had to hook up the cables again. I think we are getting there. If I need too, I will replace the ECT, if necessary.

[82Stang]

Originally Posted by HotZ28

Hook it up to a scanner and read the engine temp when trying to start engine when cold; as suggested in post #2.

Max and Z,

Disregard posts #7 and #9. I have another thing going with my S10 Blazer and I posted on the Buick forum by mistake.

So to the Buick. I don't want to take out the fuel pump if I don't have to, but I just got another one this AM. My Actron crappy scanner doesn't do much besides read codes etc. So, it's really just a code reader. Are you talking the ECT or CTS? Am I able to test it another way? I'd much rather replace that. I don't get any codes though, wouldn't it give me one for that? I'm on the verge of fixing this, but not there yet. You have me curious as to whether I should do the pump yet or not.

[Scrapper]

my moms 92 pa only thing that went wrong with it the whole time she had it. was water pump harmontic balenser,cps,and coil. when i thought it was module under coil pack bought the module put it on same thing i was wrong like i said ended up being coil pack.then about year later her maf sensor went i took it apart and cleand screen ran fine after that but she wanted a new one so i put new one on it for her.heres how it went it would run four awhile then die then it would start right back up and run little bit and die again.i think on fuel pump should be 40-48psi but that droping to 30psi that's not good.

[maxwedge]

coolant temp sensor not the one for gage.

[BNaylor]

On the VIN "K" SII 3800 engine found on the OP's PA the CTS and ECT are one and the same. CTS is the older term used. Coolant Temperature Sensor. Engine Coolant Temperature (ECT) sensor is now proper as far as terminology. The ECT output goes to the PCM module where it is processed and used for other functions and then to the IP gauge. I don't believe there is a separate sensor anymore like older GM engines. Someone correct me if I am wrong.

[82Stang]

damn, got my spark plug tester on it and now there is no spark.

ideas?

[Scrapper]

no spark no gas no start i bet it is coil pack like i said earlier...

scrapper1