I swapped my 89 E-150 from a speed density 302 to a 351W with MAF.

THe motor idles very rough and I am getting the following KOEO codes:

12- Cannot control RPM during ER Self-Test high RPM check.

13- Cannot control RPM during ER Self-Test low RPM check.

The IAC and throttle body are the same ones that I had on the 302 and are good.

When I did the swap to MAF, I had to cobble together an adapter to go from the stock truck two barrel throttle body to the single barrel MAF sensor. Could these codes be coming from an air leak in the adapter setup I put together?

 

I disconnected the battery and ran some more tests with my OTC 2000, and got the following codes:

KOEO:

32- EVP circuit below minimum voltage of 0.24 volts.

85- Canister Purge Solenoid circuit failure

KOER:

12- Cannot control RPM during ER Self-Test high RPM check.

18- SPOUT circuit open or spark angle word failure.

32- EVP circuit below minimum voltage of 0.24 volts.

41- No HEGO switching detected always lean (right side).

91- HEGO sensor circuit indicates system lean (left side).



OK- Please bear with me. Most of my experience has been with slant six powered Mopars, not fuel injected Fords.

Code 32 (the EVP one) deals with a faulty EGR right? How do I test this?

Code 85- trucks don't have these, so I don't care.

Code 12- cannot control high RPM. Vacuum leak? IAC? EGR?

Code 18- SPOUT- this is odd. I didn't mess with this at all during the repinning of the wiring harness. It should be factory correct. What is a "spark angle word failure?" "All your base are belong to us?"

Code 41 and Code 91- These are the O2 sensors. These codes say they are always reading lean. When I did my MAF swap, the wiring harness on the Mustang I used did not have provisions for a driver's side O2 sensor. So I just put a new O2 sensor in the stock location of the old speed density system- on that little pipe in between the two pipes at the Y. Was this bad? Do I need to install a true driver's side O2 sensor and relocate the passenger side sensor? What else might make the motor run lean or cause this code?

 

What EEC did you use for this swap.. what is the box code on it?
Did you use the complete mustang harness or did you patch in parts of it over the truck harness?

 

The computer was an A3M. I traded it for a reman unit from the parts store when I couldn't get the van to start. The new computer doesn't have a three letter code on it, but it interchanged with the one I traded in.

I used the Mustang harness to create an overlay harness for the injectors and the MAF. I repinned the stock wiring harness and added the new pins from the overlay harnesses.

 

OK... the EEC will have two O2 sensor inputs, did you patch the single truck sensor to both of them?
Are you using a distributor mounted grey TFI module?

 

Nope. I figured that since the Mustang didn't have the wiring for two O2 sensors I wouldn't need to add one to my van. I am using JUST the passenger side O2 sensor mounted in the factory location in the small crossover pip at the "Y" where the pipes meet before the catalytic. Looks like I was wrong, again.

Yes. I am using the distributor of of a speed density 351W with a distributor mounted gray TFI module off of the original 302 distributor I removed from the van.

I guess I will be wiring in a second O2 sensor tomorrow. Ugh. The computer and wiring harness on vans is a PITA to get to, especially with the front end and battery installed...

 

No... you don't need another O2 sensor, you just need to put a little jumper wire between the two O2 inputs on the EEC. What pinout diagrams are you using to identify everything on the mustang EEC?

 

I am using the 1990 Mustang wiring diagram on Bjorn Bremb's site, the truck speed density wiring excel diagram from Ford Fuel Injection, and the MAF mustang wiring diagram from fordfuelinjection.



So, I just need to put a jumper from pin 29 to pin 43? Will that be OK? Do I need to add a jumper for the ground, too?

 

Yes that's right.. this is exactly how the Ford MAF conversion kits for these trucks are wired so I know it works. No need for a ground jumper.

The EVP code is a head scratcher since it's on the same pins in both vehicles and you're probably using the sensor you already had so unless you moved the wire inadvertently or have a bad sensor it should be OK. See Fordfuelinjection for a test procedure.

The Spout code could be a bad pickup inside the 5.8 distributor you have, if it was a used dizzy then who knows. Good news is the one from your 5.0 distributor will swap in, bad news is the distributor has to be completely dismantled to change it. Also check that the spout plug you have is good(it's a dead short) and that the wiring between the TFI and EEC is good.

 

Thanks Conanski, I really appreciate your help with my questions. I will go out and add a jumper to the harness and see if that helps the situation. I suspect that the rough running is due mainly to the O2 input missing, but I also want to track down the SPOUT problem.

As far as the EVP goes, I am using the sensor that was on the parts 351 that sat outside for who knows how long before I bought it. If the EVP sensor from the 302 will swap on, then I can do that easily enough.

 

If you can sort out those two things I think you will solve most if not all of the code issues, so make some changes, clear the codes, and then see what comes back. I'll keep an eye out here for you updates.

 

OK. Replaced the EVS, soldered in a jumper from 29 to 43.

Reconnected the battery and ran the KOEO, KOER, and engine balance tests.

Codes:

KOEO:

85- canister purge solenoid. Don't got one, don't care about this code.

KOER:

12- can't control RPM high

13- can't control RPM low

21- ECT out of range- probably didn't let the motor warm up long enough.

41- still lean

91- still lean


Cylinder balance test- Check cylinders 4 and 7

Fuel pressure= 42PSI KOEO and 38 PSI KOER

So, I didn't get the SPOUT code, I fixed the EVP code, but the motor is still running lean.

The inability to control the idle speed and the lean running suggests a vacuum leak, but the vacuum fluctuates between 15 and 20 inches. To me, that is about right for an engine, except it shouldn't fluctuate like that, and 15 is a bit low. It should hold steady at 17-20. Does this sound like a vacuum leak? Where should I check? I torqued the intake manifolds down with a torque wrench and used new gaskets, of course.

What are the symptoms of a malfunctioning MAF sensor? I have checked and replaced about everything else on the motor.

How does the computer control the RPM? Is it only with the IAC or does it control it with the timing as well?

As far as the cylinder balance test goes, I didn't get those results yesterday. It passed all cylinders fine.

 

OK. I let the motor idle and get good and hot while I recharged the A/C system with R-134. THe motor eventually smoothed way out with just a little shaking at idle. I plugged in my OTC 2000 diagnostic computer, cleared the trouble codes, and ran the KOEO, KOER, and cylinder balance tests.

KOEO:

85 blah blah evap cannister, blah blah

KOER:

12- no high RPM control

41- lean right

91- lean left

Cylinder balance test- all cylinders passed

The code 13 coming and going and the constant code 12 leads me to believe I might have a faulty IAC valve. Once the motor smoothed out, I had a rock-solid 20 inches of vacuum. So, I don't think I have a vacuum leak, at least at the motor. I am also fairly certain that my adapter hose that goes from the double barrel truck throttle body to the single barrel MAF sensor isn't leaking. I sealed up the one potential leak joint with RTV sealant yesterday.

I am off to Autozone to get some tranny fluid, an IAC valve, a new PCV hose and PCV valve, some filters for the AIR pump intake and discharge tubes that used to connect to the air filter box, and some MAF sensor cleaner.

 

Went and bought a new IAC and MAF cleaner. Installed the new IAC and cleaned the MAF sensor wires.

Now, the van usually won't idle at all unless I keep my foot on the throttle. Sometimes it will chug along at about 500 RPM, but it is running very rough and often dies. If I keep my foot on the throttle so the van idles at 750 RPM or so, it runs OK. The van doesn't seem to have a high idle when it is cold.

Is there any way to adjust the idle speed? I see what looks like an idle set screw on top of the throttle body. Can I turn this or is that a no-no? Shouldn't the IAC control the idle speed?

 

I am now getting KOER codes 12, 13, 41, and 91, so the IAC did nothing.

My TPS voltage output is .87, would it be worth it to slot the mounting holes and bump that up to .96 or so?

How the heck do I get this thing to idle above 500 RPM and not stall?