I have an '88 bronco with a 5.8 engine with 154,000. It started to sputter and die a couple of weaks ago as well as a few other problems for a while now.I'm usually pretty good with diagnosing and fixing stuff, but this is stumping me.

I replaced plugs ,wires ,cap and rotor to no avail. I was stumped and refused to take it to a shop, so I have a scanner and scanned it myself.Here is what it came back with....

KOEO- code 11 system pass

KOER- code 12 cannot control RPM during self check or a problem with the idle speed control.

Code 18 spark out put or spark advance word failure

Code 33 EGR valve closed/ erratic or has insufficiant flow.

Code 44 Thermactor air system failure

I replaced the egr valve and position sensor, same code thrown(33)
I'm really stumped as to the rest of the codes because when I First bought the scanner a couple of months ago it scanned fine, no trouble.
Also when driving it will surge on occassion, it idles fine at 750/800.
The tach needle will jump up erratically when it surges as well.
Besides the EGR valve stuff I have replaced the battery and alternator in the last couple of months.Also I had to take it in for a brake/lamp inspection, this is when all the trouble started, though I'm not sure how it could be related.

My poor truck is dying and I'm starting to feel stupid, so any helpful suggestions would be great. Thanks in advance.

 

>KOER- code 12 cannot control RPM during self check or a
>problem with the idle speed control.

I'd clean or replace the IAB on the side of the throttle body.

>Code 18 spark out put or spark advance word failure

Spark output is SPOUT, this could be related to the TFI module?

>Code 44 Thermactor air system failure

Wouldn't worry too much about this one, it shouldn't cause your problems. The thermactor is mainly emissions.

Hopefully others will reply w/better info.

 

Thanks for the reply, Might sound dumb but what or where is the TFI module?

 

TFI is on the distributor itself. The IAC is the Idle Air Control - and can cause problems - I cleaned mine which helped the idle response - and since I have a standard - it helped with the spindown time on the clutch.

Surging can also be caused by a fuel supply problem - ie. a sticky or dirty injector - sometimes injector cleaner or a little diesel in the fuel cleans and lubes them up.

That's all I have to contribute - somewhere to start perhaps.

 

Thanks guys, I'll start on it tonight and let you know what happens.

 

Ok, I cleaned the IAC, checked all electrical connections and rescanned, this is the outcome...

KOEO- code 11

KOER- still getting code 33, EGR closed or insufficiant flow

Code 44 thermactor air system failure.

Truck seems to idle better now, tach quit jumping around, I have not done a drivability test yet. I did get on the throttle with the truck in gear and the brake on, holds any RPM without Tach jumping all over.

I'm not real concerned with the code 44, but I am still not sure why it's throwing code 33. The EGR valve and position sensor are new, as well as the tube going to the exhaust manifold.

Thanks to those that replied, you were a big help getting me pointed in the right direction.

Anyone have any other suggestions?

Next project.... Valve cover gaskets. OH BOY!!!! The fun never ends...

 

You posted on mine about the same code 33.

I was thinking it was the regulator. The vacuum tube that goes into the EGR valve is controlled by that I think. I haven't checked the vacuum on it yet, but will probably tonight.

I've also replaced my plugs, wires, EGR, EVP, cleaned throttle body and tried to clean Idle Air Bypass Valve. I'm replacing my TPS tonight. Someone said that could be the surging problem as well.

Oh, and I've also been told it could be a dirty fuel injector. Maybe I'll put in a can of cleaner.

 

I'm thinking thats about all thats left. I'll check vacuum later today,I still need to run some injector cleaner through it, good thing it's time for a fill up. I'll post my results.

 

[updated:LAST EDITED ON 02-Oct-02 AT 09:31 PM (EST)]OK I put injector cleaner in, waiting on results.

My tach is jumping around at 3000 plus RPMs,not as bad as it was though, Only thing I could relate to this was the TFI module, so I replaced it. I made sure the initial timing was good as well.

Still need to check vacuum to EGR, going to Sears for a new vacuum test kit.(Note to self don't loan stuff out and forget who has it.)

Still getting Codes 33 and 44.

I shall not let this truck beat me!!!!!!

 

OK heres the story, I did all the stuff previously posted and the truck was running OK,tach would jump around a bit at 3000+ RPMs but no surging.

Today I was driving it and the tach when at 3000 or so, would jump up to near 4000, needless to say the surge problem came back, worse than before.

I figured it's running like poo, so, nows a good time to attack the valve cover gaskets. I got all of the hoses ,wires and such out of the way. I found 5 out of the 6 upper intake bolts barely past finger tight. The only one that was tight was the one in the hole in the center(of course).

Can anyone tell me what the upper intake bolt are supposed to be torqued too? I'm thinking this was causing a lot of my troubles.
I'm feeling pretty dumb right now as well, intake leaks are the only thing that did not come to mind. Silly me, the most basic diagnosis.

Thanks again for all the help and sorry for the long posts.
I'm just trying to paint a complete picture.

 

Are you erasing/resetting your trucks computer after you've made your changes/repairs? If I recall, those codes will continue to show up until it's reset by you or after about 40 warm up cycles.

 

Yes I'm resetting it, I've tried disconnecting the battery and it cleared. I usually just use my scanner to clear all codes. I also take it for a 40-50 mile roundtrip after i do it to let the computer readjust.
Strange thing is I never get a service engine light.

Time permitting I will have it all back together this weekend and see what happens next.

 

I have just finished an engine rebuild on such a beast. The torque setting for the upper intake is 25 lbs/sq foot

 

Thanks. I have most of it back together,I need to do the "easy" side and do wires cap and rotor,again. I'll be putting the factory wires,cap and rotor on and hopefully I'll be about done. We'll see.

 

egr valves only function is to reduce exhaust emmissions and can be safely and easily disabled. yank out the vacum hose plugged into it and stuff a small bolt into the vacum hose to eliminate vacum leakage.
Using a pair of needle nose pliers with the teeth wrapped in tape gently squeeze off every vacumm line off of the intake manifold while reving up the vehicle, if no lines cause a change in performance the only other possible vacum leak is your intake manifold gasket.