Starving inline
12-06-2008, 10:31 AM
#1
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Starving inline
Hey guys I like your forum so far, My dad has a 95 inline and he is saying it is acting like its not getting enough fuel. He has already replaced the fuel pump and filter, the tank is clean, he replaced the PCM, the map sensor, TPS sensor. He says it idles fine but when you give it gas it boggs down and when you spray it with ether she seems fine. I would give you a more detailed explaination of whats happening but I'm in Bahrain on deployment and he is in Florida. Any comments would be greatly appreciated.
Thanks,
Tony
Thanks,
Tony
12-06-2008, 11:20 AM
#3
Senior Member
Welcome to the site! And thanks for all that you're doing over there, your efforts are sincerely appreciated!
As to the problem at hand - have the computer codes been pulled after these changes? If any codes are present, would help give insight as to what the issue may be. Many local parts stores will read the codes for free, however most are limited to reading only the OBD-II series and I'm not certain which vintage that truck is. If OBD-I - there's a thread somewhere on this site that explains how to do-it-yourself. It seems that your dad knows his way around a vehicle, so it shouldn't be a problem.
Another thought would be to validate the fuel rail pressure - typically should be in the 30-40psi range.
Perhaps the timing isn't advancing as it should??? Again, not familiar with that model year - mine has a SPOUT connector plug used for checking the timing - need to make sure this is seated in place.
Hopefully some other members will be along shortly with their thoughts - my thinking cap seems to be in the wash this morning. :-)
As to the problem at hand - have the computer codes been pulled after these changes? If any codes are present, would help give insight as to what the issue may be. Many local parts stores will read the codes for free, however most are limited to reading only the OBD-II series and I'm not certain which vintage that truck is. If OBD-I - there's a thread somewhere on this site that explains how to do-it-yourself. It seems that your dad knows his way around a vehicle, so it shouldn't be a problem.
Another thought would be to validate the fuel rail pressure - typically should be in the 30-40psi range.
Perhaps the timing isn't advancing as it should??? Again, not familiar with that model year - mine has a SPOUT connector plug used for checking the timing - need to make sure this is seated in place.
Hopefully some other members will be along shortly with their thoughts - my thinking cap seems to be in the wash this morning. :-)
12-06-2008, 01:27 PM
#4
Senior Member
This is the link to retrieve codes with the check engine light (you can do that on a 95, it's the last year for OBDI):
https://www.f150forum.com/f10/how-retrieve-trouble-codes-obdi-10907/
One other thing to check would be the fuel injectors. Mine did this... One injector was clogged/dead causing a mis on that cylinder. Pulling codes should or could give you some O2 sensor codes if this is happening.
Maybe the EGR system is plugged up too. Again, you'll get codes for that.
If he can get the codes retrieved, there are a lot of members here that are great at helping to make sense of them.
https://www.f150forum.com/f10/how-retrieve-trouble-codes-obdi-10907/
One other thing to check would be the fuel injectors. Mine did this... One injector was clogged/dead causing a mis on that cylinder. Pulling codes should or could give you some O2 sensor codes if this is happening.
Maybe the EGR system is plugged up too. Again, you'll get codes for that.
If he can get the codes retrieved, there are a lot of members here that are great at helping to make sense of them.
12-07-2008, 11:34 AM
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Well, he pulled codes and one of them was saying the EGR voltage was low, he said he replaced the egr...is this a code? If so then I guess he'll be looking for a bad ground or some loose wires. Also WDE he said he changed the spout connector as well
12-07-2008, 12:39 PM
#6
Senior Member
The code is essentially saying that the valve isn't positioned where the computer wants it.
EGR problems can be with the valve itself, the position sensor on top of the valve on the older models and some kind of differential pressure sensor that is prone to plugging up on the newer models, the vacuum control solenoid that provides the vacuum to the valve, or any failure of the vacuum tubing in between. One other problem, albeit somewhat rare, is that the exhaust gas supply tubing to the valve will develop a leak - allowing oxygen-rich air instead of oxygen-depleted exhaust gas back into the motor, which will cause things to run lean.
The EGR system typically doesn't become active until the motor has achieved some coolant temperature - not sure what that temperature would be but likely a bit over 100degF.
Not sure why the SPOUT connector would need to be changed - nothing on it to fail. It merely shorts the two wires out, which lets the computer know to engage the timing advance. With it out - the computer knows to remain at base timing. I was suggesting to make sure that it is seated properly.
I'm thinking your model year likely has the differential pressure position sensor. Not familiar with this, but suggest the next steps would be to inspect this for any pluggage - I think there are other threads on this site that may help, this topic has come up more than once. Also, inspect the exhaust gas supply tubing for any cracks, ensure the valve seats off fully and opens properly under vacuum. With the engine warm - make sure that vacuum is getting to the valve from the control solenoid.
Just because there's a code - it may not be causing the problems experienced. While this issue should be fixed, keep an open mind that the immediate problem may be something else such as low fuel rail pressure.
EGR problems can be with the valve itself, the position sensor on top of the valve on the older models and some kind of differential pressure sensor that is prone to plugging up on the newer models, the vacuum control solenoid that provides the vacuum to the valve, or any failure of the vacuum tubing in between. One other problem, albeit somewhat rare, is that the exhaust gas supply tubing to the valve will develop a leak - allowing oxygen-rich air instead of oxygen-depleted exhaust gas back into the motor, which will cause things to run lean.
The EGR system typically doesn't become active until the motor has achieved some coolant temperature - not sure what that temperature would be but likely a bit over 100degF.
Not sure why the SPOUT connector would need to be changed - nothing on it to fail. It merely shorts the two wires out, which lets the computer know to engage the timing advance. With it out - the computer knows to remain at base timing. I was suggesting to make sure that it is seated properly.
I'm thinking your model year likely has the differential pressure position sensor. Not familiar with this, but suggest the next steps would be to inspect this for any pluggage - I think there are other threads on this site that may help, this topic has come up more than once. Also, inspect the exhaust gas supply tubing for any cracks, ensure the valve seats off fully and opens properly under vacuum. With the engine warm - make sure that vacuum is getting to the valve from the control solenoid.
Just because there's a code - it may not be causing the problems experienced. While this issue should be fixed, keep an open mind that the immediate problem may be something else such as low fuel rail pressure.