MrMeanGreen Posted November 19, 2008 Report Share Posted November 19, 2008 I'd check the regulator, although if it's similar to the Formula, it's part of the fuel pump assembly. I fixed my bleed issues by replacing the regulator assembly and pump with aftermarket units. Quote Link to comment Share on other sites More sharing options...
prettyprix Posted November 19, 2008 Report Share Posted November 19, 2008 Injector? I had a problem like that a few years ago, turned out the injector was messed up and the O2 sensor was bad so it would stall out. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted November 19, 2008 Report Share Posted November 19, 2008 Ok kids... Key on, engine on = 41psi constant and 43psi peak while giving it gas Key on, engine off = 40 to start, and it bleeds off quickly ( <1 minute ). So... pump, regulator, leaky injector? BTW, is that a T-10 or so adjusting screw I see on top of the regulator? vinny thats way low! spec none sc 53-59 psi KOEO Key on Engine Off and it not suppose to bleed off quickly. means the check valve in the pump assm is bad! or a injector leaking. one way to tell is blocking off the line after building pressure. if it the injector it will bleed off, if the pump is whats bleeding off , the pressure will hold. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted November 19, 2008 Report Share Posted November 19, 2008 And still removed a descent part....fuel filter!!!!!! If he's on 88k miles on the original, thats an obvious issue..duh!!! I've done more work on 3800s than most and quite honestly I am real good at diagnosis via description(3800s only).....I've done, broke, and fixed everything on these cars. You'll see I'm NOT wrong ...So feel free to edit my post if I post about another kind of car...but not ones with 3800s.. KTHNXBY, Jeremiah im not dismissing the fuel dellivery issue. but you wanna argue with me everyone will see where your wrong.. here we go again with the grab it with vise grips, and rub it on concrete shit again change the fuel filter ...please..10part..could fix all your issues pressure drop once key is if is normal...you have a return line;)... not the regulutor....is your car a 97/98?...... can't see that im using my phone. if so it could be the relay in the fender did you hit boost while giving it gas. it should spike up to mid 50s psi bleed off is not normal for these cars even if it is a return system. its only normal when the check valve in the pump is junk! hitting boost...50psi...maybe you should just stay out of this section. and after readin your intro, maybe you should stay away from the keys and just learn to read! Quote Link to comment Share on other sites More sharing options...
AJ Posted November 19, 2008 Report Share Posted November 19, 2008 i was here. P.S. pressure falling off that fast isn't normal. Quote Link to comment Share on other sites More sharing options...
Cordell Posted November 19, 2008 Report Share Posted November 19, 2008 Is it falling off right to zero, or just falling off some? Aern't those the regulators that leak and send fuel up the vacuum line? Why don't you try dead heading the system, pinch off the return line and see if it changes. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted November 19, 2008 Report Share Posted November 19, 2008 Is it falling off right to zero, or just falling off some? Aern't those the regulators that leak and send fuel up the vacuum line? Why don't you try dead heading the system, pinch off the return line and see if it changes. plastic lines...... Quote Link to comment Share on other sites More sharing options...
Cordell Posted November 19, 2008 Report Share Posted November 19, 2008 plastic lines...... I Know they are, but it can be done carefully. Splicing in a repair on those takes all of 2 minutes anyway. Quote Link to comment Share on other sites More sharing options...
Buck531 Posted November 19, 2008 Report Share Posted November 19, 2008 Is it falling off right to zero, or just falling off some? Aern't those the regulators that leak and send fuel up the vacuum line? Why don't you try dead heading the system, pinch off the return line and see if it changes. Yep. Vinny. When the car is running pull the vac line off the FPR and see if it is leaking. If not and it's dry it's probably a fuel pump. And btw, if its a fuel pump, I have one from my wife's car that has 100k on it but it was running fine (it was the harness that goes to the trunk that was bad). If my in-laws still have it at their house you can have it for $30. Complete canister. takes about 10 minutes to swap out from your back seat . Quote Link to comment Share on other sites More sharing options...
DTM Brian Posted November 19, 2008 Report Share Posted November 19, 2008 My 02 Grand Prix GT 3.8 started fine after work tonight. It ran fine for the 1/8 mile drive to the Speedway on Steltzer. I filled up, and when I started the car to pull away, it would not stay running. Anything under 1400rpms, and it would die. I had to drive home (including 2-3 miles of bumper-to-bumper holding the idle up above 1400-1500. Car sounded rough at all rpms. Reminded me of a vacuum leak. No engine lights, no other symptoms. Any ideas? I would have said bad gas, but the fuel that was sitting in the fuel rail would have still been from the previous tank, I would have thought. Problem continued ~30 miles (and is still happening). Engine has 88k. Full tune up done a couple months back. Has K&N CAI and 160 stat. Send me a PM for assistance Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted November 20, 2008 Author Report Share Posted November 20, 2008 Ok folks, update. The first set of pressures was with the vac. line hooked up. I ran the test just now at atmospheric pressure, and it was 51psi. So, running, no vac, I am getting 51psi. With vac. = 41psi. Unplugged the MAF for giggles, and it ran worse and had bad throttle response. Quote Link to comment Share on other sites More sharing options...
Cordell Posted November 20, 2008 Report Share Posted November 20, 2008 Ok folks, update. The first set of pressures was with the vac. line hooked up. I ran the test just now at atmospheric pressure, and it was 51psi. So, running, no vac, I am getting 51psi. With vac. = 41psi. Unplugged the MAF for giggles, and it ran worse and had bad throttle response. Was it acting up when you unplugged the MAF? It really doesn't sound like a fuel issue IMO, that sounds normal but I don't have the specs on pressure. Could always be a faulty crank sensor, but I'd think it wouldn't run at all. Like I said before watching sensors on a scan tool might give you a new direction. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted November 20, 2008 Report Share Posted November 20, 2008 Was it acting up when you unplugged the MAF? It really doesn't sound like a fuel issue IMO, that sounds normal but I don't have the specs on pressure. Could always be a faulty crank sensor, but I'd think it wouldn't run at all. Like I said before watching sensors on a scan tool might give you a new direction. i have posted the spec several times. spec 53-59 psi KOEO Key on Engine Off so running with vacuum off should be within this range idling. Quote Link to comment Share on other sites More sharing options...
Cordell Posted November 20, 2008 Report Share Posted November 20, 2008 i have posted the spec several times. spec 53-59 psi KOEO Key on Engine Off so running with vacuum off should be within this range idling. Okay so what do you think it is Rob? Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted November 20, 2008 Author Report Share Posted November 20, 2008 Is 51 really low enough to cause issues if spec says 53? Also, there is no fuel leaking out of the FPR. Quote Link to comment Share on other sites More sharing options...
Guest 614Streets Posted November 20, 2008 Report Share Posted November 20, 2008 Sounds like a fuel pump to me but hard to say on the net without touching her , but also and you probably aready did is , yank the plugs , all of em. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted November 20, 2008 Author Report Share Posted November 20, 2008 Another neat bit of info. Last night, after every pressure reading, it would drop to 0psi within a minute or 2. It has been > 60 minutes since I checked it tonight, and it is holding > 30psi still. So, something IS up with the fuel system. Sometimes leaking down, sometimes not. Quote Link to comment Share on other sites More sharing options...
Cordell Posted November 20, 2008 Report Share Posted November 20, 2008 I've gotten caught up in thinking it's a fuel pump before, but I was wrong. It was a very similar situation to what you are describing. If fuel pressure is up to or close to spec, other things become a lot more likely and should be checked. MAF, cam/ crank sensors, and the ignition componets need checked, easiest to observe on a scan tool. Like Will said pull some plugs, all of them and look for one or more screwed up cylinders. Quote Link to comment Share on other sites More sharing options...
Cordell Posted November 20, 2008 Report Share Posted November 20, 2008 BTW if fuel pressure is up close to spec when running and revving the engine, I wouldn't get hung up on how it bleeds off. I have seen cars do that before and run great, but after they sit a little while it just takes some extra cranking to get tham started back up. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted November 20, 2008 Author Report Share Posted November 20, 2008 I'm putting it on the scanner Saturday morning... in a nice 70 degree garage while drinking a beer. Screw this weather right now. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted November 20, 2008 Report Share Posted November 20, 2008 Sounds like a fuel pump to me but hard to say on the net without touching her , but also and you probably aready did is , yank the plugs , all of em. plus one... the check valve in the pump is for sure a issue, that will casue extended crank time on cold or even hot start..id like to see fuel trims, and maf readings myself. but i just dont see them post here anywhere! Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted November 20, 2008 Author Report Share Posted November 20, 2008 id like to see fuel trims, and maf readings myself. but i just dont see them post here anywhere! Say huh. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted November 20, 2008 Report Share Posted November 20, 2008 I've gotten caught up in thinking it's a fuel pump before, but I was wrong. It was a very similar situation to what you are describing. If fuel pressure is up to or close to spec, other things become a lot more likely and should be checked. MAF, cam/ crank sensors, and the ignition componets need checked, easiest to observe on a scan tool. Like Will said pull some plugs, all of them and look for one or more screwed up cylinders. vinny what he said /\ Quote Link to comment Share on other sites More sharing options...
AJ Posted November 20, 2008 Report Share Posted November 20, 2008 don't get caught up in MAF readings as they can be wrong on the scan tool. i have seen many times where they read right on the scaner and the MAF still be the problem. even the vette's MAF went out on me last week and it read right (now speed density FTW) the trims showed me that one. since it ran worse with the MAF unplugged then i would stay away from that as the problem. since you are having pressure issues with the pump thats what i would start with since its not hard on that car. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted November 26, 2008 Author Report Share Posted November 26, 2008 Ordered a used pump from Ed Morad today, 45k miles on it, cheap and shipped put the door already. Yay for me. Quote Link to comment Share on other sites More sharing options...
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