Bronco Forum - Full Size Ford Bronco Forum banner
1 - 5 of 5 Posts

95 XL, 5.0, E4OD
8 Posts
Discussion Starter · #1 ·
I've read through a bunch of threads here and tried many things to solve my rough idle and stalling problem. was running ok before a recent tune up and shortly after the tune up. It included new plugs, wires, MSD cap and rotor, new MSD coil and connector. Drove it to the parts store and home no problem. Now I have this condition (
Here is a summary of what I've tried so far; New distributor with timing set to 10 degrees, new MC intake air temp sensor in the airbox, mass airflow sensor check clean, new air filter, ignition control module taken to AutoZone and checked good, new MC IAC module, new MC throttle position sensor, throttle thoroughly cleaned, EGR valve tested and holds vacuum and moves up and down fine (with vacuum), new MC PCV valve and hose to intake cleaned. I suspect vacuum leak, this maybe evident in the video on the vacuum gauge, but I'm not sure and could not find one using carb cleaner around the intake. Code reader shows only a happy 111 and 10. Is there something else I should check before beginning to replace all the vacuum lines?

Super Moderator
30,677 Posts
Yo scribblk,
Here is some info I provided in the Introduction section thread;

Fuel pressure is in range, KOER 28—45 PSI.

Vacuum looks ok but has a slight wobble according to my poor vision. See this Vacuum Gauge Diagnosis @ 1996 Bronco/F-Series
Includes possible Leak's in HVAC System in cab as well as underhood.
Excess air leaking into the system will upset the fuel mixture and cause conditions such as rough idle, missing on acceleration, or burned valves. If the leak exists in an accessory unit, such as the power brake, the unit will not function correctly. Or Air Conditioning when in MAX mode may switch to Defrost.

Re your " codes in the computer, only a happy 111, and 10..." I assume 10 is a typo.

Idle Air Control (IAC);

Location pic by Steve

"First let me say this little thing has many names. But they all talk about the same item under the hood. Here all the names I've had the torture of learning throughout the years:
•Idle Air Bypass •Idle Air Control •Idle Speed Control •Throttle Bypass Air •Idle Bypass •Inlet Air Controller
•Inlet Air Bypass •Intake Air Bypass •Intake Air Control.
This is really easy to test. Start the vehicle and bring the engine up to operating temperature. Allow the engine to idle without any driver input to the throttle or pedal. Go under the hood, and disconnect the electrical connector to the IAB. If the engine begins to stubble or stalls the IAB is functional and does not need to be repaired. If the engine idle does not change you should remove the IAB for inspection.
The IAB can pass ( miesk 5 Note, Ryan meant IAB can pass the Code test) and still need repair, or it can fail and not need replacing. The plunger and internal spring can get clogged with dirt and oil. This will slow down the air flow and not allow the IAB to function properly. Remove the IAB and clean it. There are 2 halves to the IAB, and you can not buy just one half, but you can take it apart to clean it. But if the internal solenoid is faulty the IAB needs to be replaced." By Ryan M.

See how to clean and test the IAC @
by Seattle FSB

This is by Nelbur; "I have spent some time this week trying to set up an air bypass around the IAC valve by cutting away some of the gasket between the IAC in and out air holes, rather than pay big bucks for Fords spacer kit. I cut away the center of the original IAC gasket from the outside of each hole to the outside of the other hole, giving about 1/2" gap for the air to pass through. I noticed an immediate improvement in the engines starting behavior, but it would still die occasionally.

For most of my trucks life it has been dying when it was started hot. It would rev up and then drop the idle so low it would die unless I would catch the idle with the accelerator. It would never die when cold as the IAC would keep the idle speed up, and it never died at stop lights. Now it's worst situation seems to be when it has been shut down for a half hour or so, and restarted. I wonder if the heat soak is fooling the ETC into thinking the engine is warmer than it really is.
I decided that more improvement could be had if I had a thicker gasket, because the original IAC gasket was very thin (0.018"). I had some 0.030" gasket material so I made my own with the same 1/2" cut out. This gave enough bypass to noticeably raise the idle speed and almost eliminate the dying. After maybe 50 starts in the last few days, it only died twice. After so many years of catching it with the accelerator it is darned hard to leave my foot off it. It is clear to me that by trial and error one can tune the air bypass without the need for the expensive Ford kit. I may combine the two gaskets for more bypass, but the idle is about as fast as I would want now, especially for driving in snow."

Nelbur mentioned this Ford kit in..Idle Air Control (IAC) Sludge; Poor Idle TSB 91-25-07 for 85-92 Bronco & F Series & many others; "...Hard cold starts, hesitation and stalls on initial start-up or during idle or decel may be caused by sludge in the throttle body and/or idle by-pass valve. Sludge deposits or oil film on the throttle body bore and plate or the idle air by-pass valve may cause one or more of the following conditions. Hard Cold Start, Stall On Initial Start-Up, Stall During Idle, Stall During Decel, Rough Idle, Rolling Idle, Hesitation During Acceleration. A new idle air by-pass service kit (F2PZ-9F939-A) is now available for service use to correct sludge contamination concerns of the throttle bore and plate only. It eliminates the need to clean the majority of past model throttle body applications. Cleaning is not required on sludge tolerant throttle body designs released for 1991 and newer model years..."
But as we know, stuff sludges.

Buy a Motorcraft IAC in event it needs to be replaced.

Was ICM Tested at the Zone more than twice? Need to heat the bugger up.

Other perps are:
Fuel quality; Oxidized fuel often turns darker over time and may even smell sour. You can check stored gasoline by pouring some into a clear glass container and comparing it side-by-side with known fresh gasoline. If your old sample looks noticeably darker than the fresh gas, you have strong evidence the gas has gone bad.

Electrical connectors; inspect for corrosion, etc at firewall connectors, PCM, etc.; especially those with broken locking tabs.

E4OD Filter; "...When ever you go to change your trans filter, Always make sure to pull out the little round rubber do hicky thingamabob. Lets call it a gromit or a seal? Theres this part of the trans filter that is inserted into the trans (a round tube that goes up into this hole ); Now the tube has a gasket of sorts that wraps around the tube ( kinda like a wide O-ring ). It forms a seal between the tube and the hole it goes in. Well what ended up killing my trans was that fact that the last guy that changed the trans filter didnt notice that this o-ring thing (gromit Or what ever) did'nt come out with the filter it stayed in the hole! He left it in there; & installed the new filter witch had its preinstalled gromit already; So what he did, is he (unknowingly) stacked two gromits on top of each other, Witch did not let the filters tube fit as it should. It was starving itself for fluid!! It was sucking air as well as tranny fluid! (in other words not working right) ..."
Source: by BlancoBronco

Filter Clip Alternative; "... have seen many threads and received many pm's as of late speaking of the stay-put filter clip used to keep the filters from falling out of the pump in the e4od. there is an alternative to using this clip. it is more expensive but also has more benefits than just using this clip. you can get a trans pan from a 03 super-duty truck. this pan has little humps in the bottom to but up against the bottom of the filter and this keeps the filter from falling down. this pan also has a drain plug and extra capacity for 1.5 more qts of fluid. this pan also allows you to use the much better elastomer gasket. it is reusable and virtually leak-proof. much better than the cork design. it does require the use of a 4x4 filter..."
Source: by thePUNISHER (Paul) at FSB

Filter Magnet; E4OD Kills Engine in Gear; " as a filter retainer; w/Ford PN and size; basically this is a magnet Ford uses to keep the filter in-place tightly into the pump; Ford pn F3RZ-7E290-AC..."
Source: by @

95 XL, 5.0, E4OD
8 Posts
Discussion Starter · #3 ·
Thank you @miesk5

Thank you so much @miesk5 for taking the time to list these possibilities. I will begin working on the vacuum system next. I will probably go ahead and replace all the lines since at this age, they will continue to fail in various places.
Regarding the codes, 10 was not a typo, just ignorance on my part. I now realize that 10 is a separation code in my reader. :duh
I should try to run the KOER test but man, its a logistical contortion.
The IAC was replaced with a new MotorCraft, so I don't think that is the problem.
The test on the ICM was done 8 or 9 times to be sure it was warmed up. The first test was a pass, then 1 fail, then 6 consecutive passes so we felt it was good.
For vacuum lines, I plan to order silicone lines. Will look now to see if there is a list of sizes to have on hand. Will also look behind the dash inside for lines to replace. This is going to be fun!

Super Moderator
30,677 Posts
Yo S,
Ok on all the updates.

Take time to do KOER.

In my leak test, jowens126 has HVAC Control Panel pics/info

Most buy silicone hoses from

95 HVAC Vaccuum & HVAC Vacuum hoses are colored IAW airflow doors control:
White for Outside/recirculation door (also called Recirc. Door that is located near passenger hood hinge),
Yellow for Panel/defrost (also called panel door)
Red for Floor/defrost (also called Defrost Door)
Blue for Mix
Black for Vacuum Source

HVAC Vacuum Diagram in a 95 by fordbronco1995

Ford advises, "A wood golf tee can be used as a plug when it is necessary to plug one end of a vacuum hose for leak test purposes."

For hose sizes, Replace Plastic Vacuum Hoses with Rubber by Booba5185 @
Seattle FSB posted "... Get the Silicone Boost/Vacuum Hose Engine Dress Up Kit and then an additional 10' of 4mm vacuum hose in the color of your choice. I used wire loom to protect the hose through the Intake Manifold, to the Diverter Valve and where it rubs on the Intake to the EVP. "
miesk5 note, Diverter Valve is behind intake manifold and enjoys the heat back there.

Vacuum Hose Sizes in 95; 25ft 5/32 line, 10ft 7/32 line 2, 5/32 vacuum tees.* 7/32 for the MAP & HVAC, 5/32 for the rest by Ojbronco4thewin

95 XL, 5.0, E4OD
8 Posts
Discussion Starter · #5 ·
Thank you again!

I have new tubing on the way and really appreciate your help. I will try to remember to post pictures of the results. Thank you so much!

Update, vacuum lines are now replaced and looking good. Here are the photos. Got them all replaced in the engine compartment and through the firewall before I ran out of hose. Here are the photos.
Started up fine, ran well until it warmed up. then wanted to stall again. This time I got a code 332 insufficient EGR Flow. Tomorrow I will run the KOER test.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.