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poor performance and codes

5K views 35 replies 9 participants last post by  JKossarides 
#1 ·
PITA, several weeks ago I put in new Autolite plugs, 9mm FMSR wires and MSD cap, rotor and 48k volt coil....so far so good...then about a week ago I was coming home up the hill and I heard a back fire then slight loss of power so when I pulled in the driveway I immediately "pulled codes" KOEO- 11-10-11 no problem but KOER got a code 34...EGR valve not opening.....the EGR valve was new several years ago and they're fairly durable and recently I replaced the EVP/EGR sensor on top due to a code: 31 which went away after replacing the EVP sensor which was probably 6 years old along with the IAT sensor which was probably 7-8 years old, the reason was I had an incident at the gas station when the BKO stalled and wouldn't restart right away, got it running poorly but got it home, codes etc.etc. replaced sensors etc. and everything was fine.

I also discovered ^ that # 3 & 4 plug wires had come off the plugs, I've never had that happen before.....very odd but I snapped them back on and it ran fine.

This morning on my way home from my hospital appointment giving blood to test for tomorrows hematology appt., I'm coming up the hill again and I feel like I'm gradually losing power again, no easy downshift into 3rd from power to weight like it normally does and another backfire SOOOO as soon as I got in the driveway I pulled codes again, KOEO 11-10-11 no problem but this time with KOER I got code: 44 thermactor air system fault, code: 34 again, EGR valve not opening and code 13 RPM idle out of range....?

I'm just wondering what's going on with the BKO all of a sudden with all these codes, up to now it's been running like a swiss watch, "what's causing these changes all of a sudden"........? Six years ago I had a code:44 and eventually figured out the "check valve" on the exhaust cross over tube bolted on the back of the cylinder heads had burned thru from rust causing an exahust leak, like a bad miss so I replaced it and all was good but I can't believe that's it rusted thru again so I'll have to either get a small mirror for visual inspection or pull off the C/O tube and look at the check valve....PITA.... all my vaccum lines appear to be in good condition....?

I've been using 9mm FMSR wires and MSD ignition parts for years without any problems what so ever.....?

Any ideas welcome, thanks ~ :thumbup
 
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#2 ·
I did the same ignition upgrade about 5 years ago and had a misfire. Turns out I managed to crack one of the spark plugs. I'd double check each plug and I'd make sure they are gapped properly (out of the box they aren't gapped). I don't recall the proper gap, but I think it's .045". Be sure to use spark plug wire holders to minimize the number of locations where the wires are physically touching (it is possible for the electrical energy to partially transfer to an adjacent wire, especially with high output ignition coils).
 
#3 ·
My OEM gap is .44, I did double check all the plugs for cracks as I was very carefull and I have the wires all staggered with plug wire clips to keep them seperated and so it looks nice and neat....

The only thing I can do is to pull the EGR valve and look inside to see what condition it's in and see that it's not stuck from opening and closing IDK. I did a mini visual of the EGR valve when I replaced the EVP/EGR sensor very recently and it looked good inside.

I can also get under the BKO on each side with a bright light and check to see if the exhaust injection tube "bolts" are tight enough not causing a vaccum leak like before, worst case is I pull it off and inspect the check valve or try a visual with a small mirror due to it's location......PITA

I'll have to go back and inspect all the vaccum lines and double check they're OK though I think it's time to get all new vaccum lines like the ones Seattle FSB replaced on his BKO, mine are probably getting brittle by now if they're all original plastic, one broke on the EGR valve that segways the four piece coupling going over the the EGR solenoids but I used a new piece of rubber vaccum line and it was fine.....?

IDK, it's hard to fathom how a vehicle can be running perfectly one day and then have all these bullshit codes, poor performance the next.......Oh well, the wonderful world of Bronco's you know.

I replaced most everything recently under the hood, very odd.....:banghead

Thanks ~ :thumbup
 
#5 ·
I'm not sure, possible EGR air stream change...IDK but I just came back from the grocery store driving slightly up/down hills and it seems when the egnie is cold it runs fine so maybe after it heats up maybe I've got a vaccum leak which I'll check for using my hand held vaccum guage and see if I can find anything......PITA...

Good Luck ~ :thumbup
 
#6 ·
the green vac line that runs from the egr to the emissions sensor over by the coil. Mine broke, and I failed emissions. It's time to do the rubber vac line mod. I know the vac lines on my 88 are starting to get bad. I just spliced in some vac hose the other day for a temp fix. They were snapping with just a light touch to see what condition they were in.

http://www.fullsizebronco.com/forum/showthread.php?t=192382

FYI, next round ditch the ford racing wires and get some msd. Mine must be 10+ yrs old and are still soft and pliable and snap on/off the plugs easy. I have a new ford racing set that feel cheap, boot are hard and stiff, and suck at snapping onto plugs securely. Same thing with accel wires, they suck for the same things.
 
#7 ·
yo BRO,

DTC 44 (KOER); Right Thermactor Inoperative; "...I had a similar issue that turned out to be the vacuum line to the Thermactor Air Bypass Valve. No CEL, just a code; 1. First check that the two vacuum lines are connected to the Vacuum Reservoir (coffee can) and the resevoir is in good repair with no leaks on the bottom. Frequently the can leaks or the vacuum lines are accidentally knocked off. Check the vacuum hose to the bottom of the Bypass Valve. Check the vacuum hose to the Diverter Valve. Check the vacuum hoses to the TAB/TAD Solenoids. Then check your TAB/TAD Solenoids. These are common easy to miss problems. Once these are ruled out all that is left is: Thermactor Air Supply Hoses. One-way Check Valves. Main TAB/TAD Valves..."
Source: by Seattle FSB (SeattleFSB) at FSB

and you know this guy, right?
DTC 44 (KOER); Right Thermactor Inoperative; "...indicates a Thermactor Air System leak which could be anywhere from the smog pump up front to include EGR solenoiids over on the right inside fender liner and all the way to the back of the engine which is what you see in the photos. There is also a smog tube that runs along the passenger side engine below the valve cover which runs to the back of the FI plenum up to a Air Bypass Valve (plastic) crossing over to the cross-over tube (exhaust) which is connected to that and the CAT, check valve and tube below. the Thermactor system is designed to capture spent gases and ultimatley send them down to the CAT to burn off etc. If you look closely you'll see the chek valve and CO tube is pipe threaded, use some anti-seize and don't over tighten and when putting the valve on the tube, you don't need a gasket for the CO tube ends but rather just use some bearing grease which melts and forms a nice gasket seal. this is a tip from Steve83; gaskets burn off and go away after a while and you're back with another vacuum leak etc..."
Source: by JKossarides ("The Bronco", Jean) at FSB

Code 44/311 or 94/314 indicates that secondary air injection system is inoperative. Code 45/312 indicates that secondary air is incorrectly routed. Code 46/313 indicates that secondary air is not by-passed when directed. Possible causes for these faults are:

• Vacuum hoses leaking, blocked or kinked.
• Secondary air injection valve inoperative.
• Secondary air injection solenoid defective or blocked.

For testing using breakout box, go to the EEC CONNECTOR pin instead;
EEC IV Connector Pin Legend by Ryan M (Fireguy50)
http://oldfuelinjection.com/truckpinouts.html

EEC V Connector Pin Depiction with Pin Numbers
http://oldfuelinjection.com/?p=3

DLC diagram
http://oldfuelinjection.com/?p=13
by Ryan M (Fireguy50)

Check for correct vacuum hose routing to AIRB/AIRD solenoids and by-pass diverter valve. See Vehicle Emission Control Information (VECI) label. Check for kinked or blocked vacuum hoses. Check for kinked or blocked air hoses. Check for disconnected vacuum hoses. If faults are detected, repair as necessary and repeat QUICK TEST. If no faults are detected and Code 44/311 or 94/314 is present, go to step 4). If Code 46/313 is present, go to step 3). If Code 45/312 is present, go to step 2).

2) Attempt To Eliminate Code 45/312 :
Disconnect and plug vacuum hose at AIRD valve. Repeat KOER SELF-TEST. If Code 45/312 is present, EEC-IV system is okay. Inspect diverter valve and check valve for faults. If Code 45/312 is not present, go to step 4).

3) Attempt To Eliminate Code 46/313 :
Disconnect and plug vacuum hose at by-pass valve. Repeat KOER SELF-TEST. If Code 46/313 is present, EEC-IV system is okay. Check by-pass valve for problem. If Code 46/313 is not present, go to step 4).

4) OUTPUT STATE CHECK :
Use only a VOM or DVOM for this step. DO NOT use scan tester. Turn ignition off. Disconnect cruise control servo (if equipped). With DVOM on 20-volt scale, connect DVOM negative lead to STO terminal at Data Link Connector (DLC). Connect positive lead to positive battery terminal. Using jumper wire, connect STI to SIG RTN at DLC. See Fig. 12 and Fig. 13. Perform KOEO SELF-TEST until continuous memory test is complete. DVOM will read less than one volt when test is complete. Depress and release throttle. If voltage increases, OUTPUT STATE CHECK has been entered. Go to step 5). If voltage does not increase, depress throttle to WOT and release. If STO voltage does not increase, go to CIRCUIT TEST QC.

5) Check Solenoid Electrical Operation :
Set DVOM on 20-volt scale. Disconnect AIRB/AIRD solenoids. Connect DVOM positive lead to VPWR terminal and negative lead to AIRB terminal at AIRB solenoid wiring harness connector. While observing DVOM, depress and release throttle several times to cycle output on and off. Repeat test for AIRD solenoid. Connect DVOM positive lead to VPWR terminal and negative test lead to AIRD terminal on AIRD solenoid wiring harness connector. Cycle AIRD solenoid on and off. If either solenoid does not cycle more than 0.5 volt, remove jumper and go to step 9). If both solenoids cycle more than 0.5 volt, stay in OUTPUT STATE CHECK. Reconnect solenoids and go to step 6).
Key off. Disconnect both AIRB/AIRD solenoid connectors and measure both solenoid resistances. Is each resistance between 50 and 100 ohms?..."
TAB, TAD, E$VR Wiring Diagram in an 86 5.0

Source: by Seattle FSB (SeattleFSB)


6) Check Solenoids For Vacuum Cycling :
Connect vacuum pump to solenoid vacuum supply port. Connect vacuum gauge to output port. Maintain 15 in. Hg at vacuum source while depressing and releasing throttle to cycle output on and off. Observe vacuum gauge. Repeat for other solenoid. If either output does not cycle on and off, replace solenoid assembly and repeat QUICK TEST. If both outputs cycle on and off, go to step 7).

7) Check Solenoids For Internal Vacuum Leaks :
Connect a vacuum pump to AIRB solenoid supply port. Connect a vacuum gauge to AIRB solenoid output port. Apply 15 in. Hg at vacuum source. Observe gauge while depressing and releasing throttle to cycle output on and off. Repeat test for AIRD solenoid. If solenoids cycle on and off, fault is in secondary air injection system (belt, pump, valve or reservoir). If solenoids do not cycle on and off, replace solenoid assembly and repeat QUICK TEST.

8) Codes 81/553 & 82/552 :
Codes 81/553 and 82/552 indicate voltage output for secondary air injection solenoid did not change when activated. Possible causes for this fault are:

• AIRB/AIRD circuit(s) shorted or open.
• Fault in solenoid or PCM.

Disconnect both solenoid connectors. Turn ignition on. Measure voltage between VPWR terminal of wiring harness connector and battery ground for both solenoids. If either voltage reading is less than 10.5 volts, repair wiring harness open circuit, and repeat QUICK TEST. If both readings are 10.5 volts or more, go to step 9).

9)Measure Solenoid Resistance :
Turn ignition off. Leave solenoid connectors disconnected. Measure resistance of both solenoids. If either reading is not 50-100 ohms, replace solenoid assembly and repeat QUICK TEST. If both readings are 50-100 ohms, go to step 10).

10) Check Circuit Continuity :
Leave ignition off. Disconnect PCM 60-pin connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between AIRB test pin and AIRB terminal at wiring harness connector. Measure resistance between AIRD test pin and AIRD terminal at wiring harness connector. If either reading is 5 ohms or more, repair open circuit and repeat QUICK TEST. If both readings are less than 5 ohms, go to step 11).

11) Check For Short To Ground :
Leave ignition off and solenoids disconnected. Measure resistance between test pin No. 51 and test pins No. 40, 46 and 60 at breakout box. Measure resistance between test pin No. 11 and test pins No. 40, 46 and 60. If any reading is less than 10,000 ohms, repair short to ground and repeat QUICK TEST. If all readings are 10,000 ohms or more, go to step 12).

12) Check For Short To Power Circuit :
Turn ignition off. Measure resistance between test pin No. 51 and test pins No. 37 and 57 at break-out box. Measure resistance between test pin No. 11 and test pins No. 37 and 57 at breakout box. If any resistance is less than 10,000 ohms, repair short to power and repeat QUICK TEST. If code is repeated, replace PCM. If all resistances are 10,000 ohms or more, replace PCM and repeat QUICK TEST.
2008 Mitchell
 
#8 ·
yo
DTC 34 - EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the flange side of the EGR by mouth. the egr is not closing properly which can cause detonation. remove the egr and clean off any carbon built up on it with carb cleaner and a brush if necessary.
Source: by miesk5 at Ford Bronco Zone Forums

DTC 34 "...in Key On Engine Off (KOEO) or Engine Running (KOER) Self-Test indicates that the EGR valve and/or EGR Valve Position (EVP) sensor may not be fully seated in the closed position. The EVP sensor voltage is greater than the closed limit voltage of 0.67 volt. Because of the preload on the installed EVP sensor, it is very difficult to determine whether the EGR valve is seated or the EVP sensor is in contact with the EGR valve stem..."
Source: by rla2005 (Randy)


DTC 13 Cannot control RPM during ER Self-Test, low RPM & Possible Causes; "...vacuum leak, use garden hose section to listen for leak noise; TB base idle off- Idle Air Control (IAC) Sludge; Poor Idle TSB 91-25-07 for 85-92 Bronco & F Series & many others; air bypass valve dirty or bad..." READ MORE
Source: by miesk5 at FSB http://fullsizebronco.com/forum/showthread.php?t=178231&page=2
 
#9 ·
Well I went to my hematology appointment this morning and no performance issues going or coming home up the steep hill, I did drop down to the second D and came up in 3rd, auto downshifted nicely power to weight at 45 mph so IDK.. it ran nice and smooth no missing or rough idle......?

Today and tomorrow I'll pull off the EGR valve and make sure it plunges open and closed, will check the thermactor injection tube bolts and check valve to see how things are looking.

I was looking at that thread http://www.fullsizebronco.com/forum/showthread.php?t=192382 yesterday and I'm going to order a red kit and replace all these old brittle plastic vaccum lines, long over due, just need to read it so I get the right size lines to fit right.

I've been using the 9mm FMSR wires for many years now and never had any problems, I'll check plug wires 3 & 4 and make sure the clips inside are far enough into the boot so they snap on correctly...


Thanks, keep ya posted....:thumbup
 
#10 ·
Thanks miesk5, I'm going to look at everything today and tomorrow and read thru your info as well, I drove it today to my doctors appointment and it ran fine, no problem coming up the hill, I put it in the second D and came up in 3rd no problem, maybe I've got a vaccum leak somewhere.

Keep ya posted.. ~ :thumbup
 
#11 ·
yo Bro,

Yes, inspect chk valve, diverter and vac lines back there; ck valves and lines last as long as a Dollar store screwdriver left in the rain
 
#12 ·
OK, right off the bat I discovered a broken plastic vaccum line that runs from a white plastic 4 connection vaccum coupling up front going to the EGR soleniods then runs along the side of the engine to the Air Bypass above the CAT at the back of the FI plenum which segways over to the thermactor check valve. Ergo code: 44 thermactor air system fault no doubt....lol lol..

I felt around the check valve by hand but I'll double check the bolts and valve with a mirror tomorrow just to be sure.

I pulled off the EGR valve and cleaned out the carbon with throttle body cleaner and put it back on so hopefully it will run better until I replace all the plastic vaccum lines with the silicone ones which should last for sometime....

Going for a test drive to the grocery store...lol lol....keep ya posted tomorrow..


Thanks ~ :thumbup
 
#16 ·
Just got done with ordering the vaccum hoses from silicone intakes and it should be here in about 3 days so I'm looking forward to the upgrade and hopefully get better performance with the new vaccum lines, Red of course....lol lol

Thanks to Seattle FSB for all the help ~ :thumbup
 
#17 ·
Here's a laugh, I paid $13.99 for 2-3 day UPS delivery from silicone intakes for my vaccum kit and it's now 4 days later with no sign of it......lol lol....I left a phone message and we'll see!


Good Luck ~ :thumbup
 
#18 ·
Saturday, Sunday, and Monday (1/21) don't count as shipping days - business days are what is usually quoted for shipping times
 
#21 ·
Well believe it or not it showed up today out by the garage door in the rain and in a US Postal shipping box so I don't understand why I paid $13.99 for 2-3 day UPS delivery, anyway I got 4 sets of vaccum hoses 10mm, 8mm, 6mm and 4mm but I need to check with Seatle FSB regarding the quality.....? IDK I'm sure if I like them or not......keep ya posted..:rofl:


Thanks ~ :thumbup
 
#24 ·
The Silicone Intake Silicone Vacuum Lines are very high quality. See the photo below for an obvious difference in thickness which prevents vacuum collapse. Again, be sure to get an additional 10' of 4mm line in order to have enough to complete your Smog Emissions Line replacement. You will also need a few inexpensive vacuum tees available from your local Auto Parts store to route the common VRES Vacuum Source to the TAB/
TAD/EVR Solenoids. I also use Wire Loom to protect the lines in areas of heat or abraision. You will not use the old vacuum connector boots as the lines will go directly on the various Solenoid/VRES/Sensor nipples. Finally, be sure to place the correct vacuum line on the correct side of the VRES as this is actually a Check Valve. And see the lower photo for Cruise Control Vacuum Filters and Check Valves.























 
#34 ·
Reference the cruise control vacuum line picture (above)

The PO of my '91 had removed the cruise control system, but he gave it to me with the Bronco when I bought it, minus the vacuum lines. I am trying to return it to stock form, but cannot find a vacuum filter or that 3-way check valve for the CC vacuum circuit.

Does anybody have a source for these parts?
 
#25 ·
Seattle FSB:

Keeping in mind my BKO is an 86 and yours is a 90 I was wondering, the biggest Red vaccum line looks like it's for the brake booster re-route to the back of the FI plenum, PCV etc. is that correct, my concern is that it feels a bit soft did you have any problems with that application....?

I'll have to go to O' Reillys and look for plastic tees for hook ups, I'l do a visual inspection so I have a good idea of what to replace...so I'll get familiar BEFORE I start taking it apart.....lol lol but it seems all that's really needed is just to match the closest size hose to existing lines.....?

Hopefully this will turn out better then the shipping experience.....lol lol

Thanks ~ :thumbup
 
#26 ·
These are the Red silicone booster vaccum lines I just bought from Silicone Intakes, see what you think...:thumbup


This is the best I could do, Cntrl C, Cntrl V and Copy shortcut aren't working for some reason so go here for video..www.supermotors.net/17406 it's the one on the left but you may have to hit "refresh" to get it to download I seem to be experiencing problems today....sorry!
 
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