Idling Problem / Dying - 95 5.0

RustangJeeTee

New Member
Joined
Jan 2, 2015
Messages
51
Reaction score
0
Location
Dee Eff Dubya
My car has been hunting for idle and dying at stop signs. It's not doing it all the time, but it seems to be happening more often. I smoke tested it to look for a vac leak and smoke came pouring out of the back of the motor underneath the plenum. I'm pretty sure its the PCV assembly and from the looks of it I'm going to have to R&I the intake to get to it. Before I spend anymore effort on it, does anyone have any thoughts? This motor isn't as easy to work on as my 4.6 was.
 

mcglsr2

Well-Known Member
SN95 Supporter
Joined
Jul 4, 2011
Messages
3,410
Reaction score
40
Location
Orlando
Does it still have the smog stuff on it? And if not, I assume the holes in the back of the cylinder heads have been adequately plugged?

Could very well be your PCV, it's back under the plenum towards the driver side IIRC.
 
OP
OP
RustangJeeTee

RustangJeeTee

New Member
Joined
Jan 2, 2015
Messages
51
Reaction score
0
Location
Dee Eff Dubya
Does it still have the smog stuff on it? And if not, I assume the holes in the back of the cylinder heads have been adequately plugged?

Could very well be your PCV, it's back under the plenum towards the driver side IIRC.

Smog Pump is still there, but bypassed. I saw that there's some stuff with the IAC that becomes a problem with these, and that could be it. Even if it is, I'd still need to get the vacuum leak fixed.
 

mcglsr2

Well-Known Member
SN95 Supporter
Joined
Jul 4, 2011
Messages
3,410
Reaction score
40
Location
Orlando
Could be IAC, but I think you are on the right path - get all vac leaks shored up first. See if that corrects the issue.
 

toyman

Active Member
Joined
Aug 25, 2008
Messages
874
Reaction score
9
The PCV is located at the rear of the lower intake manifold. The vacuum line runs to a nipple on the underside of the upper intake from the PCV. This rubber hose is likely broken or cracked due to age and heat.
 

CC'S95GT

Post Whore
Joined
Apr 19, 2008
Messages
10,738
Reaction score
178
Location
Hampton ,Ga.
the surging idle is usually caused from a vacuum leak.
When replacing the PCV, don't forget the screen under it. It's hard to see and likely coked up with baked on oil. It help to remove with a pair of needle nosed pliers.
 

Michael Plummer

Active Member
Joined
Feb 20, 2007
Messages
517
Reaction score
111
Location
Brockton, MA
The PCV is located at the rear of the lower intake manifold. The vacuum line runs to a nipple on the underside of the upper intake from the PCV. This rubber hose is likely broken or cracked due to age and heat.
:laughing4: Good advice, and the best place to start.
 

5literstang95

New Member
Joined
Jun 28, 2014
Messages
10
Reaction score
0
I had the same problem and eventually it got to where I couldnt make it out of my driveway. I tried IAC, TPS, new dizzy, plugs, wires, and cleaning TB and MAF. It ended up being a bad MAF. Bought a new one and problem solved. Good luck.
 

toyman

Active Member
Joined
Aug 25, 2008
Messages
874
Reaction score
9
I had the same problem and eventually it got to where I couldnt make it out of my driveway. I tried IAC, TPS, new dizzy, plugs, wires, and cleaning TB and MAF. It ended up being a bad MAF. Bought a new one and problem solved. Good luck.

Speaks volumes to pulling codes. A $25 reader will pay for itself quickly.
 

5literstang95

New Member
Joined
Jun 28, 2014
Messages
10
Reaction score
0
Speaks volumes to pulling codes. A $25 reader will pay for itself quickly.

I pulled the codes and all it was saying was misfire and left bank lean. I had a shop do it and it came up MAF. But yeah, you are absolutely correct
 
OP
OP
RustangJeeTee

RustangJeeTee

New Member
Joined
Jan 2, 2015
Messages
51
Reaction score
0
Location
Dee Eff Dubya
I don't have any codes popping up, and I thought that it was harder to read because obd1. Anyway, if I have to replace the pcv assembly, do I need to pull the intake? I don't really want to, but a guy I work with says I should.
 

NXcoupe

Well-Known Member
Joined
Aug 16, 2009
Messages
1,369
Reaction score
80
No, don't pull the intake. Pulling the upper helps to access it on these cars, but not necessary. Just unplug the pcv valve from the hose and plug the hose and smoke check it again. If no smoke then you are chasing your tail, move onto other checks.

These OBD1 cars will rarely tell you a sensor like the maf is bad. It's stupid but a lot of times parts changing with a known good unit will net results that couldn't be gained with a scan tool. I always pull codes first and go from there.
 
OP
OP
RustangJeeTee

RustangJeeTee

New Member
Joined
Jan 2, 2015
Messages
51
Reaction score
0
Location
Dee Eff Dubya
Well, I replaced the PCV valve, grommet, and screen. It fixed the vacuum leak, but I'm still having an idling problem. Next step is the koeo test I guess.
 

Addermk2

Well-Known Member
Joined
Mar 7, 2006
Messages
2,534
Reaction score
55
Koeo tests won't help. Does the car still have a stock throttle body?

Have you tested your coolant temp sensor?

Have you tested your O2 sensors?
 

Latest posts

Forum statistics

Threads
77,435
Messages
1,502,114
Members
14,917
Latest member
virocanah

Members online

Top