I need Ford EEV IV help- engine stalls when I turn electric radiator fans on

[michigander]

Background on the motor - It is a 1989 5.8L truck motor (speed density), converted to MAF with an aftermarket harness, using an aftermarket MAF, and an A9L computer. It has ran flawless since the first time i started it.

Tonight I reassembled my buggy to the point that I could start it up and test some things out.

Here are the events

1- battery was dead, found my booster. After 3 attempts the buggy finally starts.

2- Idle is crappy, pretty much stalls as soon as it returns to 700 rpm or so. Might be because I had the battery cable disconnected to it lost all adapt table.

3- I clean the MAF and leave the air filter off (air filter was solid mud). This might not have anything to do with the saga, but who knows.

4- Buggy starts fine and idles OK. Within 5 minutes the buggy idles great.

5- I let the coolant temp reach operating temp, then flip on the electric radiator fan, and the engine stumbles for about 1 seconds then stalls. I have 2 radiator fans, the same problem happens regardless of which fan I turn on.

6- repeat 5 numerous times.

7- restart the buggy but use the throttle to keep it running when i turn the electric fan on. Even at 1000-1200 rpm it has a miss.

8- restart buggy with electric fan off and everything is perfect at all RPMs

Pull codes, here is what I have

KOEO
81 Boost control solenoid - Solenoids
AIRD solenoid - Solenoids and Air Injection
3.0L SHO - Inlet Air Solenoid - Solenoids
I don't know what this code is, but everything I read shows it is because smog is removed

82 2.3L TC - Fan Control wire shorted to ground - A/C and Fan Circuits
AIRB solenoid - Solenoids and Air Injection
same as above, it is because smog is removed


84 EGR Vacuum Regulator - Solenoids
EGR cutoff solenoid - Solenoids
EGR Vent solenoid - Solenoids
EGR and smog removed, makes sense....

95 (R) AIR not Diverting (AIRD) - Air Injection
another smog code



Memory Codes
33 ALL - (O, M) EGR did not open/ respond during test or if memory code, did not open intermittently
another smog code, EGR deleted


66 Vane Air Flow (VAF) or Mass Air Flow (MAF) signal low -
This one bothers me. If the MAF is operating correctly until I turn my fans on, then I am suspecting some sort of electrical interference. My fans draw big amps and are about 10 inches away from the top of the motor (and MAF). What confuses me is that I have never had this issue.


Or, there is option C- none of the codes above are causing this issue.

What sensors on the motor would be extremely sensetive to electrical interference?
Why would it just randomly start now? cold weather?

Can someone tell me if code 66 will set a CEL? I did have the CEL come on, and the RPM smooths out. About 5 seconds later the CEL turns off and the RPM stumbles. It does this over and over

[low_range]

So it runs fine w/o the fans on, but like crap when theyre on? Then there has to be a problem with the fan wiring. How did you wire up your fans?

[michigander]

someone from my local board nailed the problem. I had left the air filter off. when I turned a radiator fan on, it was disrupting the airflow in the engine bay, which caused bad flow readings through my MAF, eventhough I thought my MAF was way out of the way of the airflow. I put the filter back on and it idles great.

[Ho Shorts]

Originally Posted by michigander

someone from my local board nailed the problem. I had left the air filter off. when I turned a radiator fan on, it was disrupting the airflow in the engine bay, which caused bad flow readings through my MAF, eventhough I thought my MAF was way out of the way of the airflow. I put the filter back on and it idles great.

This is good info.

I am running EEC IV on my wife's truck and am fighting an idle issue. It has an engine driven fan so turning it off isn't an option. I will pull it off and see if it fixes the problem

If so, then I suppose I will be building an air box.

Derek

[FORDTECHGURU]

read two posts up, very common issue..

[dahoyle]

Originally Posted by rexman

The Fan or Fan's Are Drawing To Many Amps.When Ya Said battery Was Dead.Why Did That Happen,Sure It Starts With The booster.Leave The Jumper Box On Start,Let Battery Build Up And Turn on Fans,I'll Bet It Will Run Fine.Same for The Other Member,Check The Alternator To See If It Is making The Right Amount Of Volts.

Way to jump in with the wrong answer, after the OP found the problem, and posted what it was....

As for HO Shorts problem.... Please explain to all of us here, how he has a charging problem, when he says nothing about it in his thread, and specifically states that he has a mechanical fan...

Guess reading comprehension isn't your strong suit.