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95 F150 Rough Idle issues

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Old 11-21-2010, 07:15 PM
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95 F150 Rough Idle issues

Ok since I jacked someone elses thread and then my original got way to long, someone suggest that I start a new one with whats been checked, changed, etc.
So to start, its a 95 F150 302 with 175,000miles on the clock. My issues are that regardless of cold or warm the truck has a very rough idle, the exhaust smells bad(doesn't really smell like eggs), horrible gas MPG and seems to be worse sitting at a light while in gear and brake applied(it seems to build up). I thought it was my TC but has been checked out by 2 shops and they said its working as advertised. Here are the things I have checked and changed-
New plugs and wires, cap and rotor, new IAC, new TPS, MAF sensor cleaned. EGR valve is blocked off, but still has vacuum attached. The vacuum on the motor is 20-22in Hg, no leaks are present. Fuel pressure is 32psi while the pump is on and also when the truck is idling. I have done all the vacuum test per this website and it has all checked good - How to Use and Interpret a Vacuum Gauge
Timing has been checked and verified. When the IAC is disconnected the idle drops but not enough to stall the truck. The idle is at about 750-800 but when the IAC is disconnected its barely above 500rpm. Also I can reach 6 of the 8 injectors and I can feel them clicking, however when I pull #2 I don't seem to feel the truck change in performance at all however I get some change when I pull the others and #7 is questionable! Also I am sure this doesnt really affect what I am feeling but it started after I changed the fluid in the trans and TC. But at about 1300rpm and up there is a clicking from the trans(only in park or neutral) the trans shop said that it was my EPC solenoid and I will be replacing that along with the 1/2 shift solenoid and TC lock up solenoid. I am sure there is something I forgot to mention but here is the links from the past threads if someone wants to go back through them. But again that is why I am starting a new thread. https://www.ford-trucks.com/forums/9...f-a-cliff.html
https://www.ford-trucks.com/forums/1...ight-lope.html
https://www.ford-trucks.com/forums/1...converter.html
 
  #2  
Old 11-22-2010, 07:09 AM
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Without reading everything have you check for fuel in the vacuum hose to the Fuel Pressure Regulator (FPR)?
If there is fuel in the line or if it comes out of the nipple of FPR when you turn on the key it is bad.

A lot of the time bad idle and surging is caused by the Evaporative Emission System (EVAP).

By the way to check fuel pressure you turn on the the key with pin #6 of the EEC self-test plug grounded. You should get 40-45 psi fuel pressure.
 
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Old 11-22-2010, 10:50 AM
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Yes I have checked the FPR and no fuel is present. Also I will redo the fuel pressure check this weekend along with the compression check. As far as the EVAP system, what can I get rid of, what needs to be done to get rid of it or do I need to keep it also there won't be any issues in the future! I live in Florida and there are no state requirements, if that helps but I really need to get this truck fixed!
 
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Old 11-22-2010, 01:30 PM
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To get rid of the EVAP system you would need to:
1. Change to vented gas caps (if you can find them).
2. Plug the roll-over valve/vent hole in the top of the fuel tanks.
3. Plug the vapor input vacuum nipples in the Throttle Body.
4. Never park it inside to prevent fires.

In other words the EVAP system is a good system to have.
 
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Old 11-22-2010, 03:02 PM
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Got it! Well I will be keeping that system!
 
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Old 11-23-2010, 07:57 PM
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What can I check to see if the EVAP system is working. Also is there anyway to check fuel injectors without removing them.
 
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Old 11-23-2010, 11:40 PM
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Does my 95 F150 have a MAP sensor? If so where is it? Cause I can't seem to find it if I have one!
 
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Old 11-24-2010, 08:37 AM
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Originally Posted by teamshadyinc
Does my 95 F150 have a MAP sensor? If so where is it? Cause I can't seem to find it if I have one!
Your 95 has a MAS sensor and not a MAP sensor. It is located in the air cleaner box.

You can use a 9 Volt battery to test each injector. It should click when power is put on its pins.
You can also lessen to them with a long screw driver up to your ear with it idling.

The EVAP system has a solenoid valve between the charcoal box and the throttle body. It has a hose on each end and a wire coming out of it. You should not be able to blow through it unless power is put on its wires. It should only open with a warm engine and with the truck at highway speed.
 
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Old 11-24-2010, 01:32 PM
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Subford thanks for the input. I am able to feel all the injectors click while the truck is running, however like I said earlier if I disconnect #2 injector the truck idle makes no changes and barely if disconnecting #7, but if I disconnect any of the others, the rpm drops! Also I will check out the EVAP solenoid, when I got the truck I replaced the hoses on it but didnt really now what it was for. Also is there any test that I can do other than blowing into it? Also to test it I should try blowing through it with power off, there should be no passage unless the truck is up to operating temp(that is with power connected)
 
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Old 11-24-2010, 02:26 PM
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Yes you should not be able to blow through it unless the is up to operating temp (with power connected and grounded by the computer).
 
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Old 11-25-2010, 03:09 AM
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how long have you had the egr blocked for?
you may check the o2 sensors?
you may try running a can of sea foam through the vacuum line for the brake booster it will free up any exess carbon in the combustion chambers it will smoke like all get out but run about half a can of it through not reving it up more than just enough to keep it running then shut it off and let it sit for about 30 mins the fire it up and run the rest of the can through reconect the brake boaster line and take it for a drive down the highway with a fairly heavy right foot
 
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Old 11-25-2010, 09:55 AM
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The EGR valve hasn't been blocked longer than a week, I will open it up this weekend. As far as the seafoam treatment, I did that when I did the major tune up, that was about 800miles or so ago! It smoked a lot but didn't really improve things. It will get another one on the next oil change just to make sure everything is out! I will be doing a compression test and checking the temp of the cylinders this weekend just to make sure all the cylinders are up to specs.
 
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Old 11-26-2010, 12:07 PM
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i have never liked doing away with the egr because of the way the ford intakes are the egr helps the fuel atomization out quite a bit i found that out on my 01 crown vic it ran awesome for about three days after i blocked it off then it started runnin horribly and i unblocked the egr and it ran fine again
 
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Old 11-26-2010, 12:32 PM
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Yeah I will be taking out the penny today, I was thinking of getting rid of the whole EGR system, but the kit to trick the ECM is not really on the list of needed essentials at the moment plus I know that the EGR is not causing my misfiring!
 
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Old 11-26-2010, 01:11 PM
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I have ran with it blocked for years with just a little bit better performance with it blocked.
I would not remove the penny until you get it fixed.
 

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