Hi all, I'm not new to mechanicing on fords, been doing it a long time. working on a 1993 ford Aerostar, 4.0l v6. Getting code 33 on the computer and the funny thing is there is no EGR valve on this motor. All problems with this engine is pointing to the EGR vavle, rough idle, poor gas milage and of course the code.
So my question is: if there is no EGR then why the codes? yes origional motor in it. and why the rough idle?
not the MAS, not the TPV and not the oxygen senser, and not the cat.

Please any help would be apreciated

thanks wayne

 

Hi Wjtownsend:

Welcome to our FTE forum

The codes you get are probably not 33. I bet it's 111 sent twice.

Rough idle, poor mileage, etc... usually does not result in a code if it's just regular maintenance that's required.

I'd look at the plugs and wires, O2 sensor, MAF, the usual suspects.

 

I agree, just do a tune up using Autolite or Motorcraft Wires, and Autolite or Motorcraft plugs for the 3.0, or Autolite or Motorcraft Double Platinum/Denso Iridium wires. Any other plugs or wires will result in poor results, low power, and having to do it again soon. Replace the cap and rotor if you have a 3.0, and check the ignition timing. If the O2 sensor has not been replaced within the last 60 thousand miles, consider replacing it. And clean the MAF sensor with a MAF sensor cleaner, electrical parts cleaner, or throttle body cleaner. Replace the air filter and fuel filter if they need it. And if that does not improve things, you may have a bad fuel pressure regulator. Lots of stuff, but if you take them a few at a time, its not bad. All vehicles require maintenance, Aerostars just last long enough to make it worth it. Now if I had an Astro and needed to do this much tune up work, I would add alternator, water pump, EGR valve, EGR sensor, and AC compressor to the list.

 

I'm not sure about '93 aero, but there is no EGR on '86-'92 aeros.

 

run a cylinder balance test...believe '93 4.0L is sequential fuel injection

all you wanted to know about reading OBDI codes
see section on cyl. bal. test click

clean IAC mounted on driver side of plenum at throttle body....common cause of idle roughness
http://fordfuelinjection.com/index.php?p=39

 

Thank you all for the input but some of you have a hard time reading, I am a mechanic, I have done all the simple things like plugs, wires and filters. it has had a tune up. and i guess some of you have missed the part where i said it is a 4.0L V6 and I know it does not have an EGR Valve in it!
On any other motor the problem would be the EGR Valve but this one does not have it so what other things could make it do the same thing?

And as I have said before, The oxygen senser, MAF and the TPS is not the problem, cleand or replaced all of those. No vaccume leaks found.

So please keep giving me some ideas but remember I have checked and replaced some of the things your talking about.

Between Ford and searching online, I have not found anything about this motor not having an EGR Valve with the same problems. Oh ya The code is right, still a 33, this has been done by me and two other mechanics with differant code readers. Thank you all again

Oh ya did clean the IAB and didn't change a thing

 

Has someone put in another ECU ( later version) on your vehicle? or maybe it's been re-flashed with the wrong info?........ I'm just guessing really ! but since you have checked out the obvious maybe it's something obscure? Some OBD scantools can check sensors graphically, maybe you have an intermittent fault that only shows on idling. Many a rough idle has been caused by Cam sensor fault , does your van have CKP sensor or a distributor ? Also what about Fuel pump & line pressure ?

Aeroman59.

 

disconnect MAF, run and read codes...do you get a correct failed MAF code?

is TB throat area clean, especially at plate gap? critical for proper idle air flow control
4L's are prone to the TB throat gumming up due to the PCV feed coming into the air flow prior to the TB

from Ford Service manual
Exhaust Emission Control System

The exhaust gas recirculation (EGR) system is designed to reintroduce exhaust gas into the combustion cycle, lowering combustion temperatures and reducing the formation of oxides of nitrogen.

The amount of exhaust gas reintroduced and the timing of the cycle varies by calibration. Timing and volume are controlled by engine rpm, engine vacuum, exhaust system back pressure, engine coolant temperature and throttle position. The EGR valve (EGR valve) (9D475) is vacuum actuated. The vacuum hose routing diagram is shown on the Vehicle Emission Control Information (VECI) decal.


Vehicle Emission Control Information Decal

Vacuum hoses on the engine use a color stripe to aid in hose routing checks. The stripe will usually be the same color as on the VECI decal, but the correct vacuum hose routing must be verified by using the correct component connections shown on the VECI decal.

if decal is still on veh. will show if your's has EGR

my Ford Service cd shows no EGR on 93 or 94, 96 does have EGR with DPPR, no info avail on 95

'93, '94 are bank injected so no balance test possible

what does compression and leakdown tests show?