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21 Posts
Discussion Starter #1
During the code test we got code 13. The idle is between 800-1000 and sometimes 1200. I had a couple of days of dying within a mile of the house when I was stopping at a light. Now it isn't dying but it is surging from 400-1500 rpm while driving. It has been tuned up, checked timing, cleaned IAC, vacuum gauge test was fine (not the hand held one checking every line). Any ideas would be greatly appreciated. The hubby is not real interested in finding out the problem but I am because it is an awfully heavy vehicle for a couple of girls to push if it wont start.

Super Moderator
26,341 Posts
I assume the code came up during da KOER = Key On Engine Running portion?
DTC 13 is Cannot control RPM during ER Self-Test low RPM check.
possible causes are:
Suspect Idle AIR Control -
Overview & Testing; "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..."
Source: by Ryan M (Fireguy50) at

Removal & Cleaning in a 93 5.8
Source: by Bobby (blue) at

Location pic in an 88 5.8
Source: by Travis L at

EGR stuck open -
Stuck open will act like a vacuum leak and cause a rough idle and stalling
Source: by Larry C at

Overview; "...This air valve allows engine vacuum to open the EGR valve. The EGR system recycles burnt exhaust gasses into the intake. This lowers the amount of fuel needed, and lowers toxic Nitrogen Oxides in the emissions. The EGR only operates at highway cruise conditions..."
Source: by Ryan M (Fireguy50) at
Testing; "...There shouldn't be any vacuum at the EGR valve at idle or any time your ass is under the hood fiddling with it, to put it plainly, except for perhaps a very light residual vacuum from the EVR. Check ALL of your vacuum lines FIRST, and the vacuum reservoir for leaks..."
Source: by SigEpBlue (Steve) at FSB

Test, Vacuum Video in a 96 using a hand-held vacuum pump/gauge
Source: by Tony K (Boat Dude, Big Blue) at

Test; "...Hook up your hand vacuum pump to the EGR valve and slowly apply a vacuum. If the EGR valve is functioning then the engine should begin to run poorly and stumble. If you apply full vacuum and notice no RPM change or can’t pull a vacuum at all, then check for a faulty diaphragm in the valve or a restriction of the EGR tube, exhaust or intake manifold EGR ports. I have run across many concerns where the EGR passages in the intake manifolds become plugged with carbon and prevent EGR flow, so try to keep this in mind during testing. Repair and continue testing..." read more
Source: by

COMPREHENSIVE articles; see all Ford EGR Valve Topics; Note, site won't allow you to return to this page
Source: by tomco-inc

Other possible causes are:
vacuum leak, rule out
TB base idle off,, rule out for now until all other tests are done
IAC dirty or bad, rule out

21 Posts
Discussion Starter #3
Thanks for the reply. It narrowed down the list of problems alot that we had to check. Yes the code came on during KOER

Super Moderator
26,341 Posts
ok, and btw there are more info/testing, Component Location pics, etc LINKs in my site under Electrical, Sensor, Idle Air... etc.
and Emission, Exhaust Gas Recirc...
EGR Valve
EGR Valve Position (EVP) - MIESK5 NOTE: EVP is used on all years except for 95 5.8L California models & all 96, they use the DPFE Sensor instead of EGR Valve Position Sensor (EVP)
EGR Vacuum Regulator (EVR)


21 Posts
Discussion Starter #5
found the tube from the bottom of the egr to the exhaust was broke in two. hoping fixing that and replacing egr will fix the problem. i have an exhaust leak on that side that we are hoping goes away with this fix.

Super Moderator
26,341 Posts
ok, Get a new tube from NAPA, etc. Some temp folks at the parts stores don't know da nomenclature, so calm em down and watch what they search for on their computer system; here is one source that sells direct w/great customer phone service and also distr to NAPA etc. PCI Inc.
Ford Air Tube (EGR) #152 $31.00
Replaces O.E. E8TZ-9D477-A and O.E. FOTZ-9D477-A
Use with #128 connector

EGR Tube/Manifold Connector
20.0 - 20.5 mm thread one end, 29 mm thread other end.
Replaces O.E. E5TZ-9J470-A.
Use with #152
#128 EGR Tube/Manifold Connector qty: $8.20

The check valves, etc are also on that page at PCI.

EGR Tube TSB 92-22-08 for 88-91 Bronco, F Series & Econoline
Source: by Ford via Steve83 (Steve, That dirty old truck) at

TSB 92-22-08 EGR Tube

Publication Date: OCTOBER 21, 1992

LIGHT TRUCK: 1988-91 BRONCO, ECONOLINE, F-150, F-250, F-350

ISSUE: The EGR tube may break resulting in an exhaust noise. This occurs because of a weakness in the EGR tube design.

ACTION: Install a new stronger EGR tube and exhaust manifold connector fitting. Refer to the following procedure for service details.

1. Remove the existing EGR tube and exhaust manifold fitting.
2. Install a new EGR tube (FOTZ-9D477-A) and new flared exhaust manifold connector fitting (FOTZ-9F485-A).
3. Tighten the EGR tube fittings to 25-35 lb-ft (34-47 N-m).
4. Tighten the exhaust manifold connector fitting to 40-50 lb-ft (54-68 N-m).
5. Secure all vacuum lines away from the EGR tube after replacement.
6. Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

FOTZ-9D477-A EGR Tube
FOTZ-9F485-A Exhaust Manifold Connector Fitting

SUPERSEDES: 90-10-11
WARRANTY STATUS: Eligible Under Basic And Emissions Warranty Coverage For 1988-1991 Models, Bumper To Bumper And Emissions Warranty Coverage For 1992 Models

922208A Install EGR Tube - Econoline 1.7 Hr.
922208B Install EGR Tube - F-Series, Bronco 1.2 Hr.

see if a check valve is rusted thru in the secondary air system, causing an exhaust leak /sound.

Crossover Tube, Diverter & Check Valves & Hoses Location Diagram in a 5.8
Source: by Steve83 (Steve, That dirty old truck) at
btw, PB Blaster works great on the valve/tube..
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