• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

94 cobra possible idle issue?

  • Thread starter Thread starter Bowen94
  • Start date Start date Feb 15, 2024
  • Tags Tags
    idle issue running rich
B

Bowen94

New Member
Feb 15, 2024
5
0
1
Washington
Feb 15, 2024
#1
  • Feb 15, 2024
  • #1
First time poster here looking for some advice where to look next. I've tried a bunch of things but no luck maybe someone here has a good technique to try. So run down on car. 94 cobra, afr 185cc heads, f303 cam set straight up, edelbrock rpm2 intake with spacer for clearence reasons, has a 70mm bore. 1.6 roller rockers, ac delete, smog delete. 2.5 off road h pipe. Bama 4 bank chip tuned for what was done. Original cobra 24lb fuel injectors.So what it's doing... from the start it fires up fine but was chasing a idle issue. Fires up rpm comes up then would just fall to stall. Ran codes. No codes other than for egr not being there. Checked fuel pressure, was sitting at 35 koeo goes up to 40 koer fuel pressure regulator test is fine. I had a he'll of a time trying to adjust base timing without it idling so ended up changing a bunch of parts. But here's where it gets interesting I ended up coming to the maf sensor which seemed to fix the idle issue. I bought a duralast maf put it in and boom, car is idling seemed like the system was picking up and learning fine. But it appears that when the car comes up to temp (though even this is inconsistent) it will stop idling... as long as I give it some throttle it will fire up every time just will not idle. Let it sit awhile and she will fire up and idle again. I noticed last night running it trying to check timing again, might be a coincidence but put the timing light on adjusted timing light on screen and all at once the fan came on and the idle dropped out. Coincidence? Another strange thing I noticed about the car while I was performing different tests a consistent thing I noticed every time I went to pull codes with code reader ill click the button to start the test and instantly it turns the radio on my counter off? I believe it's disrupting the wifi song will keep playing but it kills the radio connection. What the heck is that? By checking the plugs another consistency is that it's running very rich. Multiple sets of various heat range plugs and they all just get black soot on them. Yeah any advice would be much appreciated. Thank you guys
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,821
3,951
183
Claremore, OK
Feb 15, 2024
#2
  • Feb 15, 2024
  • #2
Bama chips are junk. Have seen more people remove them and get an SCT and problem solved. Not saying that is it but man are they garbage.
 
B

Bowen94

New Member
Feb 15, 2024
5
0
1
Washington
Feb 15, 2024
#3
  • Feb 15, 2024
  • #3
AeroCoupe said:
Bama chips are junk. Have seen more people remove them and get an SCT and problem solved. Not saying that is it but man are they garbage.
Click to expand...
Yes I've read this, im not sure if the stock system will support the mods or not. I've also began entertaining a vacume leak somewhere. Havnt found one at the motor anywhere but maybe evap canister purge is part of my problem?
 

General karthief

wonder how much it would cost to ship you a pair
5 Year Member
Aug 25, 2016
27,868
10,542
203
polk county florida
Feb 15, 2024
#4
  • Feb 15, 2024
  • #4
Got a vacuum gauge?
 
B

Bowen94

New Member
Feb 15, 2024
5
0
1
Washington
Feb 15, 2024
#5
  • Feb 15, 2024
  • #5
Yes ran a vacume test, that's the odd part. When it's idling it checks out fine, once the idle drops the readings are all over the place when it dies. Fire it back up after a bit all fine again. Are there any vacume accesories that are switched at a time or point in warm up?
 

General karthief

wonder how much it would cost to ship you a pair
5 Year Member
Aug 25, 2016
27,868
10,542
203
polk county florida
Feb 15, 2024
#6
  • Feb 15, 2024
  • #6
Bowen94 said:
Are there any vacume accesories that are switched at a time or point in warm up?
Click to expand...
No, sometimes a bad brake booster will change the idle when you step on the brakes (at least I've experienced that) but I think that is not your issue.
What RPM is it trying to idle?
What is your vacuum reading at idle?
The E cam will need to idle a little higher than stock, first thing I would do is pull the chip and see how it runs.
I've heard that the 94-5 models don't play well with letter cams but I believe that is a rumor.
You may still need to chip it
I should ask if you did the idle reset per instructions?
 
B

Bowen94

New Member
Feb 15, 2024
5
0
1
Washington
Feb 16, 2024
#7
  • Feb 16, 2024
  • #7
I cant remember the reading, ill do it again today. Funny one thing I tried last night and it gave me a code this time. I double checked my timing, dead on the money, let it run untill it stalled again I pulled a small vacume line off and it was idling again with no drop and stall. I let the car sit and idle for atleast an hour periodically shutting it down and restarting just fine, I even re hooked the vacume line up at different times while it was still running and the idle never dropped but when I left the line hooked up and shut it down to restart would not idle, she needs more air or less gas. The code I got this time for koer was 116r I believe. Engine temp volt to high or to low. Where is the voltage issue coming from, next issue to figure out I guess.
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
42,951
21,130
234
Box behind Walmart
Feb 16, 2024
#8
  • Feb 16, 2024
  • #8
The voltage issue generally indicates a bad sensor or wiring leading to the sensor. Usually, it's the sensor but I do understand that you're working through some wire issues too so...

You do not appear to have a vacuum leak.

What you do appear to have is a problem with either [one] of the spark tables or [one] of the fuel tables in your "chip".


Have you tried running the car at all without the chip? It should run and idle. You haven't changed the injector size or MAF, is this correct? The E-cam is not so radical that it shouldn't run. I've run that cam on a stock A9L with minimal effort and 19s.
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,821
3,951
183
Claremore, OK
Feb 16, 2024
#9
  • Feb 16, 2024
  • #9
If you have the stock MAF, stock ECU, and 24 lb/hr injectors then pull the chip and it will run. Don't get me wrong a good chip like and SCT and a dyno tune will make more power but it will run without the Bama chip.
 
B

Bowen94

New Member
Feb 15, 2024
5
0
1
Washington
Feb 16, 2024
#10
  • Feb 16, 2024
  • #10
For clarification I'm running the f cam, sorry If I mistyped e. Yes this was my suspicion from the beginning over fueling, reading the plugs it's obviously a rich condition im dealing with. I'm going to try pulling the chip again when I get the chance. I did this before but to no change, has anyone dealt with one of these chips damaging maf sensor itself? Series of events: got the car together fired up fine but had this idle issue from the start. Tried a multitude of things but only found it would idle with A BUNCH of vacume disconnected. I'm this time I tried pulling the chip, same results only wanted to idle with vacume pulled. So I figured it wasn't the chip. Put the chip back in tried a bunch more, started throwing parts at it came to maf (original to motor before build) replaced it and now it idles for a bit but stalls after 15mins or so. Pulled one vacume line and it will idle all day now. There is still inconsistencies in it but it is much better. I'll get to getting some readings tonight hopefully.
 

General karthief

wonder how much it would cost to ship you a pair
5 Year Member
Aug 25, 2016
27,868
10,542
203
polk county florida
Feb 16, 2024
#11
  • Feb 16, 2024
  • #11
Which vacuum line did you pull?
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
42,951
21,130
234
Box behind Walmart
Feb 16, 2024
#12
  • Feb 16, 2024
  • #12
If the EEC is EECing then you should be able to pull codes.

Might be a good place to start.
 
You must log in or register to reply here.

Similar threads

L
95 gt engine vibration
  • lenzgt
  • May 11, 2026
  • 1994 - 1995 Specific Tech
Replies
6
Views
156
1994 - 1995 Specific Tech May 26, 2026
lenzgt
L
I
1994 Cobra - Fuel Pressure Drops Revving at Idle
  • IconicSilverGT500
  • Apr 11, 2026
  • 1994 - 1995 Specific Tech
Replies
16
Views
375
1994 - 1995 Specific Tech Apr 24, 2026
Mcmahst
T
Help with a 95 5L crank no start
  • TheBubbaJoe
  • Nov 4, 2025
  • 1994 - 1995 Specific Tech
Replies
3
Views
416
1994 - 1995 Specific Tech Nov 5, 2025
AeroCoupe
9
1995 5.0 just cranks
  • 9GT5
  • Jun 29, 2025
  • 1994 - 1995 Specific Tech
Replies
1
Views
350
1994 - 1995 Specific Tech Jun 29, 2025
AeroCoupe
R
94’ SN95 - Intermittent lope & bogging at moderate rpm
  • Red5.0ho
  • Nov 2, 2025
  • 1994 - 1995 Specific Tech
Replies
5
Views
407
1994 - 1995 Specific Tech Nov 3, 2025
General karthief
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?