Need help: 97 Expedition wont take gas

[strokin393]

I just got an expedition and its now running but when you push on throttle it won't take the gas and wants to shut off. I was wondering what could be causing this? I changed the fuel filter, cleaned meter, tb, and the iac valve and it still doing it plus pops thru the intake when trying to give it gas.

 

[strokin393]

I just took out 3 plugs and they covered in gas

 

[strokin393]

Is there anyone out there that might know what's going on?

 

[tmajikman]

check and see if your tps is good, it should read with the key on engine off at 0.98 and go up to around 5 volts at full throttle, could be a bad maf sensor, check your vacuum hoses/routing, make sure the elbow on the back of the intake is not broken or split, I would check all your grounds and also go through and double check all of the connectors and make sure nothing is disconnected

 

[strokin393]

check and see if your tps is good, it should read with the key on engine off at 0.98 and go up to around 5 volts at full throttle, could be a bad maf sensor, check your vacuum hoses/routing, make sure the elbow on the back of the intake is not broken or split, I would check all your grounds and also go through and double check all of the connectors and make sure nothing is disconnected

I had a guy put a code scanner on it and showed nothing wrong and I cleaned mass air and checked that vacuum hose and found nothing wrong with it. Why would it not want to take gas, want to shut off and pop thru intake? I hope to get truck going soon.

 

[tmajikman]

A back fire sounds like a timing issue, it could have jumped a tooth, or a plugged cat, no exhaust getting through the exhaust system. My sisters toyota did what your talking about and it was the maf causing the ecu to think it needed all that fuel, excessive fuel that is. Could also be a fuel pump or fuel pump regulator, just because there is fuel, it may either not have enough, or may have too much fuel pressure.

 

[strokin393]

What do I need to test this stuff and how? I'm thinking a fuel gauge to see if I'm getting to less or to much fuel, but how do I test the rest? Thanks

 

[strokin393]

I need to know what to test and how?

 

[kikokiko]

have you changed plugs already?

 

[strokin393]

Its been to cold for me outside to put new ones in and I have one that's still in there soaking in WD-40. I'm pretty sure that's not my problem but I could be wrong. I just need this truck running so I can have something to drive. The person I got it from took the mid pipe off with the converters because they think they are clogged up and that also could be the case but the scanner reads that I have nothing wrong unless the cel needs to come on. It wouldn't stay running until I changed the fuel filter and now it runs and moves at idle but when you give gas it wants to shut off, it won't take the gas. You gotta keep hitting the throttle to get the rpm's up and pops through intake. What all should I check, test, replace, and how? Thanks

 

[strokin393]

have you changed plugs already?

I changed the plugs and gapped them to .54. The truck don't want to start or it cuts off as soon as I think I get it started.

 

[markanthony]

I would start with replacing the throttle positioning sensor. This should be located on the other end of the butterflies in the throttle body. One end is the throttle cable. the other side is the sensor.

If that don't work. I would go for plugs and coils.

Their is a reason why their is fuel in the cylinder. Plug not burning it off, and why is the plug not work (coil not working) Find out if it is just one or more then one. The plug should have a fuel smell to it. but if it is wet with fuel. WHY? If more the one is wet. I would think of multiple coils gone bad (not likely) I would more think of the throttle sensor.

The throttle sensor tells the computer when the throttle plates in the throttle body had been moved. The other sensors tells the computer air temp and a measured amount of air flow. If it is bad, it would add more fuel. or not enough fuel.


If the truck is in park. When it is at idle. Floor it. Does it run up at all? at idle. does it run smooth or run rough? If you hold it steady at lets say 1000 rpm. Does it run smooth? Will it run up that high? If their is a crack in the system some were. It would not post a code. If a coil was bad their would be a code.

Just a starting base.

Oh.. Is the air filter clogged.

 

[strokin393]

I would start with replacing the throttle positioning sensor. This should be located on the other end of the butterflies in the throttle body. One end is the throttle cable. the other side is the sensor.

If that don't work. I would go for plugs and coils.

Their is a reason why their is fuel in the cylinder. Plug not burning it off, and why is the plug not work (coil not working) Find out if it is just one or more then one. The plug should have a fuel smell to it. but if it is wet with fuel. WHY? If more the one is wet. I would think of multiple coils gone bad (not likely) I would more think of the throttle sensor.

The throttle sensor tells the computer when the throttle plates in the throttle body had been moved. The other sensors tells the computer air temp and a measured amount of air flow. If it is bad, it would add more fuel. or not enough fuel.


If the truck is in park. When it is at idle. Floor it. Does it run up at all? at idle. does it run smooth or run rough? If you hold it steady at lets say 1000 rpm. Does it run smooth? Will it run up that high? If their is a crack in the system some were. It would not post a code. If a coil was bad their would be a code.

Just a starting base.

Oh.. Is the air filter clogged.

I changed all the plugs, 3 new coil packs because I had them from od expedition, new air filter, new fuel filter, cleaned tps, cleaned tb, and cleaned the mass air. The truck did run but when you push on throttle it didn't take the gas and wanted to cut off, I had to hit throttle real fast let off hit it and let off over and over to even get it to bring rpm up. Now that I changed the plugs and put 3 new coil packs on, the truck won't start and I put everything back on and in place. I don't hear the fuel pump from inside the truck when I cut the key on. the old plugs were black and wet from fuel when I took them out.

 

[strokin393]

Fuel pressure is only at around 25 to 28 or 28 to 30, I can't remember which of the 2. Should be what, 40 to 45?

 

[strokin393]

While running at low rpm it sometimes idles up then goes back down and the fuel pressure goes up as well.

 

[markanthony]

I think u might be best off to change out the pump and or the pressure regulator. One or both of those might be acting up...

 

[strokin393]

I just got a new pump sat and will be changing that sometime this week. Thanks