95 idles is very low and rough?????

9

95conv.5.0

New Member
Jun 19, 2006
12
0
0
Bremerton, Wa
#1
Hi everyone; I need some advice as to what to try next, my 95 5.0 idles very low and rough, I've changed the distributoe, TPS, thermostat, waterpump, had it timed ( it's right on)and put in new spark plugs, it dosen't get real warm anymore but it almost dies when its at an idle warm or cold but runs great when it not sitting at a stop. I don't know what to do next, I'm going to put on a new dist. cap and wires even though the ones on look alright to me(???).I had a diagnostic run on it and the only 2 things bad were the pick up coil and the TPS (replaced)I just don't know what to try next ( I'm just learning to work on my own car). can anyone help???
Thank you
 
#2
do a search about IAC....also have you taken off your MAF .......I only say this because I had the same problem...MAF was not "clocking" as I was told...and once adjusted it got better....I know you said you replaced TPS but do a search here as well on checking it....I'm sure more knowledgeable peeps will chime in..
Will....BTW..welcome to Stangnet
 
#4
Good advice above. Is it a stick or auto? If an auto, dont go crazy adjusting the idle too high.

Take detailed notes of idle adjustments you make so you can get back to where you started.

Good luck.
 
#6
Many things can cause bad idle. The first thing you should always check is the charging system because a bad battery or alternator can throw off the voltage to all sensors like TPS or MAF or power to ignition. After that, check for vacuum leaks which cause a rough idle. You may not hear the famous whistle, but spray all fittings, hoses and intake down with brake clean and look for a raised idle or unstumbling effect.
Also, how many miles are on the car? Your wires may look good but that doesnt mean anything. If the plug wires still have numbers on them then chances are they are original and if you have anything over 75k miles then they probably should be changed. Engine sensors dont usually go bad, and its usually the easiest cheapest thing thats hanging you up. I'm ASE at Midas and rough idles are almost always bad plug wires or a vacuum leak. When your TPS is bad you usually get a fluctuating idle, and they are adjustable so you may want to check the voltage on it at idle. It should read as close to 1 volt, like .99 at idle and then on up to like 4.5 at WOT. Test with motor off, ignition on!
Lastly, how about that EGR system. If the valve is clogged or stuck you can get poor performance and rough idle.
Shot in the dark, but is the air filter good?
 
#7
Here is another mechanical idle setting write up. This has fixed almost all idle problems for the people that have used it.

MECHANICAL IDLE SETTING

'94-'95

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.
 
#9
Thanks for you advise guys, I think I got it now, I put on a new dist. cap & rotor, new plug wires, serpentine belt, next thing will be new spark plugs this weekend, it is running alot better now almost like it was when I bought it 2 years ago. oh yea, it has 157459 niles and its the first time I put new wires on it.
 
#12
Well I was wrong, now its heating up again, I just put new waterpump and theromstat, the temp gage was reading low to average but the engine was real hot when the hood gets opened and now the gage is going way up again and the car is running like crap again, knocking and pinging, barely got it home today. On the idler pulley bracket there is alot of grease or oil, I wipe some off with a Q-tip and it was black, that wasen't there yesterday when I put the new spark plug wires on, I can't find it in my book and and don't know whats it's hooked up to or what it does??????? I'm also not sure if the blower motor is comming on or not, it use to but with \everything else I can't hear it anymore. thanks again
 
#13
95conv.5.0 said:
Well I was wrong, now its heating up again, I just put new waterpump and theromstat, the temp gage was reading low to average but the engine was real hot when the hood gets opened and now the gage is going way up again and the car is running like crap again, knocking and pinging, barely got it home today. On the idler pulley bracket there is alot of grease or oil, I wipe some off with a Q-tip and it was black, that wasen't there yesterday when I put the new spark plug wires on, I can't find it in my book and and don't know whats it's hooked up to or what it does??????? I'm also not sure if the blower motor is comming on or not, it use to but with \everything else I can't hear it anymore. thanks again
Click to expand...
Blower motor (for HVAC) or the cooling fan (for the radiator)? THe latter could easily be part of your issue.

Manual fan switches are always nice, in case something on the control path decides not to switch it on. Or run a stand-alone controller (a la DcControl.com ).
Good luck.
 
#14
Forgive me if this offends you but I have to throw it out just in case.....when you changed the thermostat and water pump did you leave the radiator cap off and occasionally squeeze the hose to make sure you got all the air pockets out......this will cause you temp to rise........If I'm off base .....sorry......thought just went thru my head.....
 
#15
95 Conv, is it a manual or automatic? Believe it or not, I had another car that ran hot because the transmission was low on fluid (automatic). That would also explain idling like crap.
 
#18
I just want to thank you all for your advise, I got it running right now, just a little while age, WHEW! I ended up replacing the Idle Air Control Valve ( I got one at the wrecking yard and cleaned it real good) made a gasket for it, took out the Idle adjustment screw, the new TPS and the DPFE sensor and cleaned them all and put it back together, it started right up and seems to run great (hopefully for more than 2 days this time), also the new thermostat I just put in was bad and had to be replaced again....Again thank you all for the great advise, if I haden't been for that I wouldn't have looked for those things... Renee' & her Atlantic Blue Convertible GT Mustang
 
#19
95conv.5.0 said:
I just want to thank you all for your advise, I got it running right now, just a little while age, WHEW! I ended up replacing the Idle Air Control Valve ( I got one at the wrecking yard and cleaned it real good) made a gasket for it, took out the Idle adjustment screw, the new TPS and the DPFE sensor and cleaned them all and put it back together, it started right up and seems to run great (hopefully for more than 2 days this time), also the new thermostat I just put in was bad and had to be replaced again....Again thank you all for the great advise, if I haden't been for that I wouldn't have looked for those things... Renee' & her Atlantic Blue Convertible GT Mustang
Click to expand...

:OT:

I love that color.
 
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