MattParanoia Posted October 17, 2011 Report Share Posted October 17, 2011 I am not sure why it does it, but if I ease onto the gas it runs like it should, then once I get the gas pedal to ~3/4 I hear the fuel pump cut out.This normally happens after the car has been warmed up. Then once the cars been running for about 5 minutes trying to give it any gas causes it to stutter, like its not getting in there.I recently replaced the spark plugs, wires, injector connectors, and took the fuel pump off and reinstalled. When I took the fuel pump off some chunk of metal fell out, I was thinking that could be part of the problem, somethings blocking the pump from getting enough gas. P.S. would it be possible to attach another fuel filter before the pump? Quote Link to comment Share on other sites More sharing options...
Scotty Dont Posted October 17, 2011 Report Share Posted October 17, 2011 You should clean and inspect your entire fuel system if a chunk of metal was in there. Quote Link to comment Share on other sites More sharing options...
TopDawg_43 Posted October 17, 2011 Report Share Posted October 17, 2011 Are you using a stock fuel pump? Is your car stock? It sounds like more of a timing issue then a fuel issue. The fuel pump just runs. It does not know how much throttle you are giving. Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 18, 2011 Author Report Share Posted October 18, 2011 Yeah, the car is stock (except for the fuel pump). The reason its so confusing for me is that the fuel pump runs fine, and then once it goes over a certain amount of throttle the pump cuts out for a couple of seconds then turns back on.The guy who had it before me put the pump thats on there now (it also looked l like they added a 5 point relay at the pump).I did buy a new pump, would I have any problem using a Walbro 255lph on an otherwise stock car? Quote Link to comment Share on other sites More sharing options...
TopDawg_43 Posted October 18, 2011 Report Share Posted October 18, 2011 No, not at all. You can run a Walbro on a stock car, as many have done. You may have a bad MAP sensor. I don't know how to check other to replace it with a known good sensor. Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 18, 2011 Author Report Share Posted October 18, 2011 Yeah I thought the same, but then when I tried ordering it they sent me a part that doesn't go to my car. The map sensor is built into the maf isn't it? aka the brick in the intake. Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 18, 2011 Author Report Share Posted October 18, 2011 Alright so I took a video to see if this might help since I am horrible at explanations. http://www.youtube.com/watch?v=kf27J8H0LtcI really hope this helps as I am now lost, I put my Walbro 255 on and I thought it was running better, but it just took longer to get this problem. Quote Link to comment Share on other sites More sharing options...
Indiana Posted October 18, 2011 Report Share Posted October 18, 2011 That could be many things. Could be a cracked head. If the cracks just got to where they leak in coolant it happens after its heated up and just gets worse afterward. If its no fuel it won't rev up but it won't rev up and be choppy, it might be some other clog in the fuel line. It might be some hacked up wiring for that relay because they couldn't figure out they had a dirty connection that was the power feed to the ECU (which is what keeps the pump turned on in stock form) and the pump is fine and its the ECU that is the problem. You need to remove or at least trace whatever that added wiring was that's where I'd start. There was some reason why that was done. Quote Link to comment Share on other sites More sharing options...
TopDawg_43 Posted October 18, 2011 Report Share Posted October 18, 2011 Seeing as how the boost gauge shows boost, while the engine is decelerating, that tells me that you need to replace the MAS. Yes, its in the intake. Let me look when I get home, I use to have a few of them laying around. Yes it's in the airbox. If that does not get it, you are going to need to start doing what Indy said above. Quote Link to comment Share on other sites More sharing options...
Indiana Posted October 19, 2011 Report Share Posted October 19, 2011 See if you have an intercooler hose blown off too. If anyone have been messing with wires at the MAF plug they mave have gotten some reversed. There's 4 wires in the MAF plug and two are of one color and two another color of the 6 used and if they are swapped it won't work they have very different circuit paths it just happens they are the same color. If it has a 1G MAF plug, it might be connected upside down. Its showing boost when there isn't any because of something happening with the MAF readings or you have an ignition issue because the boost gauge isn't a vacuum/pressure gauge using a reference hose. http://www.b2600turbo.com/images/boostgauge1.jpg Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 19, 2011 Author Report Share Posted October 19, 2011 It is still a stock MAF, I was thinking about grabbing a 1G MAF from a junkyard and upgrading to that. Quote Link to comment Share on other sites More sharing options...
JAinsworth Posted October 19, 2011 Report Share Posted October 19, 2011 If you go with a 1G MAF, make sure you get one for the turbo'd version. It will have an 8 pin connector. The one with 6 pins is a downgrade.Jimmy Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 19, 2011 Author Report Share Posted October 19, 2011 Yeah I was reading the 1g MAF upgrade forum, I'll make sure its from a turbo, Thanks Jimmy. Just got to hope that they have something at the yard. Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 20, 2011 Author Report Share Posted October 20, 2011 Alright, so I haven't started the car in ~2 days and when I did a couple of minutes ago as soon as I give it any kind of gas the fuel pump shuts off causing the engine to stutter and stall. It does the same with the MAF unplugged, although it'll run a few seconds longer. I haven't had a chance to get to a yard yet to find a new MAF. Quote Link to comment Share on other sites More sharing options...
Indiana Posted October 20, 2011 Report Share Posted October 20, 2011 Yeah, the car is stock (except for the fuel pump). The reason its so confusing for me is that the fuel pump runs fine, and then once it goes over a certain amount of throttle the pump cuts out for a couple of seconds then turns back on.The guy who had it before me put the pump thats on there now (it also looked l like they added a 5 point relay at the pump).I did buy a new pump, would I have any problem using a Walbro 255lph on an otherwise stock car?Have you traced these wires and see what the previous person has done? There's no reason to have to do that unless it was a larger power feed and the old pump power was used to close the new relay. Are you SURE the pump loses power or do you just think that because the engine won't run? How can you hear a pump cycling like that when you are driving? Usually its bad spark plugs, dirty injector clips, loose injector clips, bad vacuum advance, slow reacting governor plate in the distributor, clogged up fitlers or blown headgasket and I could name some more but when you say the pump cuts out you're only going to get some replies about a pump that shuts off but maybe that's not what's really happening? If you think its the pump that turns off, stick a battery in the trunk and wire it up to stay running then go see if it doesn't do the exact same thing. Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 20, 2011 Author Report Share Posted October 20, 2011 (edited) Have you traced these wires and see what the previous person has done? There's no reason to have to do that unless it was a larger power feed and the old pump power was used to close the new relay. Are you SURE the pump loses power or do you just think that because the engine won't run? How can you hear a pump cycling like that when you are driving? Usually its bad spark plugs, dirty injector clips, loose injector clips, bad vacuum advance, slow reacting governor plate in the distributor, clogged up fitlers or blown headgasket and I could name some more but when you say the pump cuts out you're only going to get some replies about a pump that shuts off but maybe that's not what's really happening? If you think its the pump that turns off, stick a battery in the trunk and wire it up to stay running then go see if it doesn't do the exact same thing. The only wires that he added was a power cable that ran from the battery straight to the relay and an extra ground cable, it still has the stock wires from the original pump. I believe that the pump isn't running because when the car is started it has a whine to it that you can hear clearly from inside the car, when you rev it up slowly you can still hear this whine. But when you just press the pedal down the whine disappears and comes back a couple seconds later. The reason I can hear this is because I have not actually had a chance to drive this car anymore than around the block since I have bought it. I know that it's not the spark plugs or wires they're brand new, also wired brand new injector clips after doing these 2 items the car ran better, but still not right. I checked in the distributor, looks brand new (confirmed with previous owner that he replaced the cap and rotor in attempt to remedy the problem). How can I check the vacuum advance, or the governor plate? I have been replacing the filters as I get them, they don't seem bad overall. I am hoping its not a bad head gasket, as of right now I have no reason to believe it is, although it wouldn't surprise me. EDIT: Would it be a feasible option to try another ECU, as I do have an extra anyway o.O Edited October 20, 2011 by MattParanoia Quote Link to comment Share on other sites More sharing options...
Indiana Posted October 20, 2011 Report Share Posted October 20, 2011 You need to get a compression testor and find out what's going on the motor sounds strange and not like its firing on all cylinders. If there's a bad connection for the ECU and that's the ECI fuse link that will cause the pump to cut out same as if the tach signal wire is bad or maybe the wires to the distributor are ready to break off at the connectors. Could be the knock sensor wire doing the same thing and as the engine vibrates it loses connection and that will pull timing back. Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted October 31, 2011 Author Report Share Posted October 31, 2011 That may have just been my camera, the car sounds good in person, just putts out when the fuel stops flowing. Could it be something in the ignition system? I doubt the coil, because that would probably just stop it from running altogether, but what else could be possible? Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted November 10, 2011 Author Report Share Posted November 10, 2011 I still cannot figure out what this problem is, I have swapped my ECU and Knock Box to one from an 88, swapped my MAF to a 1G, right now I have the exhaust completely off to check the first cat seeing if it was clogged and it'll run, but same problem as before. I have the fuel pump connected to the stock wires. Quote Link to comment Share on other sites More sharing options...
FijiPhil Posted November 11, 2011 Report Share Posted November 11, 2011 Sorry if this has been addressed but are there any vacuum leaks? I fought a problem with a car that would hesitate and sputter (not that bad, but pretty bad) for a while and it turned out to be a bad ignition coil. Its not likely. But it is a possibility. You might want to look into giving that a shot. Also it looks like the car is running way hot in that video! I would be reallllly hesitant to run it much with it getting that warm. You sure the cooling system is up to snuff? Have you verified that the timing is 10 deg BTDC? If you can only get it to like 7 deg before or 13 deg after and run out of rotation then the distributor is off a tooth. Those are some of the things I would look at. Good luck with it! Quote Link to comment Share on other sites More sharing options...
Caliber308 Posted November 11, 2011 Report Share Posted November 11, 2011 A clogged Catalytic converter can cause this, dirty Fuel filters can cause this, low compression can cause this, a bad Fuel Pump can cause this, bad Spark Plugs can cause this, a dirty Air Filter can cause this. A bad Stock MAS? Not likely. Bill Quote Link to comment Share on other sites More sharing options...
Caliber308 Posted November 11, 2011 Report Share Posted November 11, 2011 (edited) I am not sure why it does it, but if I ease onto the gas it runs like it should, then once I get the gas pedal to ~3/4 I hear the fuel pump cut out. You can't hear a Fuel Pump run or not run sitting in the Drivers seat . You also might have a "stuck wide open" or malfunctioning Secondary Fuel Injector. Due to the Injector itself, or a badly installed Injector clip. Does this happen at appox. 2500 to 3000 RPMs? Bill Edited November 11, 2011 by Caliber308 Quote Link to comment Share on other sites More sharing options...
mistapickles Posted November 11, 2011 Report Share Posted November 11, 2011 In my case a bad alternator caused symptoms like that, turn on your headlights and see if it gets worse....I had great voltage but low amperage and when the car had low amperage pull it was fine, but as I would turn on the radio, wipers, headlights etc, it would get worse. Quote Link to comment Share on other sites More sharing options...
Caliber308 Posted November 11, 2011 Report Share Posted November 11, 2011 (edited) Yeah, the car is stock (except for the fuel pump).I did buy a new pump, would I have any problem using a Walbro 255lph on an otherwise stock car? Did you upgrade the Fuel Filter and Fuel Hoses after installing the Walbro? If your finding metal pieces in the Fuel Pump...You might want to check the In-tank Fuel Filter on the end of the Fuel Pick up tube. Bill Edited November 11, 2011 by Caliber308 Quote Link to comment Share on other sites More sharing options...
MattParanoia Posted November 11, 2011 Author Report Share Posted November 11, 2011 You can't hear a Fuel Pump run or not run sitting in the Drivers seat . You also might have a "stuck wide open" or malfunctioning Secondary Fuel Injector. Due to the Injector itself, or a badly installed Injector clip. Does this happen at appox. 2500 to 3000 RPMs? Bill I can hear the fuel pump run from the driver's seat since it has a very distinct whine while running. The cut out happens anywhere from 5k when the engine is still cold and just started, to 1.5k after its been running and warm then it'll cut itself out. Quote Link to comment Share on other sites More sharing options...
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