The computer will control the idle speed via the IAC but the TPS has to be within the "idle speed" range(about 0.5 to 0.99v) with the throttle plates closed and the IAC disconnected, and usually it is suggested that the TPS be near the top of this range or 0.9-0.99v. The screw on the throttlebody is factory set and shouldn't be altered normally, but if you cannot get the TPS withing range by moving it on it's mounting screws some adjustment of this screw may be necessary.

You should also check that you are getting 12v and a solid ground to the heater circuit at the O2 sensor, this could cause lean/rich codes as well.

 

OK, thanks. It is still wired like the factory set it, but I'll double check it.

 

Well, I tried to take it for a test rive but I found two problem. First, there is a really sluggish engagement of the transmission and very delay shifts. I am hoping this is just a TV cable adjustment. Second, the headers I used don't clear the engine cover.

Soooo, this project is on hold. I am going to have to pull the exhaust manifolds off to replace them, and while I am doing that I am going to pull at least the upper intake manifold off and check for vacuum leaks. I am also going to try a different O2 sensor on the off chance that the NEW one I installed is faulty.

I am really getting fed up with this whole endeavor.

 

Still chipping away. I discovered that the injectors for cylinders 3 and 4 were not fully seated in the intake. Now the lean running codes are gone, but the motor still can't control the idle RPM. Still getting codes 12 and 13.

New IAC, new throttle body gasket, EGR gasket is good and EGR valve is fully seated.

Any ideas?

I checked and the motor is still timed to 10 BTDC. Could it be a bad MAF sensor? What about something wrong with the guts of the distributor?

 

the injector wiring does match the firing order of the cam correct. does the idle fluctuate all the time or just in park?

 

Idle fluctuates all the time. Injector wiring is for the 93 Mustang HO motor, which should match the firing order of 84 351W HO motor.

I put the old IAC back on, and all codes but 12 have cleared. I guess the "new" IAC from Autozone was poo.

Anyhow, after swapping headers, I took the van for a long drive, ran some Seafoam in the gas, and now it idles smooth when hot. HOWEVER, the main idling problem was when it was cold before, so I need to let it cool off and then I will check the idle again.

Also, a loud whistle has appeared that I can't track down. I have disconnected all hoses, checked tightness of all bolts, replaced all gaskets, and I still have this whistle. Idle vacuum is 17-20 inches, so it can't be that bad of a leak, but I need to track it down.

Finally, to add injury to insult, I discovered that the AOD in my van is toast. It slips really bad now and is leaking badly from the torque converter area. I guess the old 302 was so worn out that the slipping didn't show up, but now that the van has a 351 with MAF the tranny is showing its true condition. It used to not leak at all, but now it is a pretty steady leak from the dipstick tube and the converter area. Ugh. Maybe I overfilled it, and maybe I need to adjust the TV cable, but it takes a long time to engage in drive or reverse and it takes time to re-engage when I come to a stop while driving.

I swear, this van hates me.

 

What flex plate did you use between the 5.8 and the transmission? You need a 28oz AOD/4R70w flexplate and no others, a C6 or E4OD flexplate will push the TC too far back into the trans fluid pump and destroy the transmission. Any guesses how I know that?

 

Oh. ****. I used the flex plate from the C-6 the 351 was bolted to before. I still have the AOD flex plate, but it is bolted to the back of the 302 I took out. There's no way that the 1984 C-6 flex plate will work?

This ruins my week. Why the hell did Ford use so many freaking flex plates?!?!

Well, I guess the good news is I still have the rebuilt C-6. I just need to pull it out of my 84 van and stick it in my 89 van.

I guess I will pull the AOD, and get it rebuilt, someday.

 

I know the feeling.. it ruined my week when it happened to me too.

 

Crap. So the 302 flex plate has the wrong balance for the 351 and the 351 flex plate has the wrong depth for the AOD. Where can I find the right flex plate?

 

Summitracing has the correct flexplate.. they're not expensive.

 

OK, looks like I need a 28 oz balance flex plate that will work with an AOD tranny.

It looks like Ford-AOD.com the ultimate AOD Transmission Perfromance Website sells the flexplate I need as part number 55F: "Fits 1968 to 1980 302 motors , 1965 on 289 motors and 1969 to 1981 351W motors with a 28-ounce imbalance factor. Will work with C4, C6 and AOD transmissions. 14.23" OD / 164 Teeth."

Does that look right?

 

Yeah that's the one, it seems it is OK to use an AOD specific flexplate with a C6 but it's not OK to use a C6 specific flexplate on an AOD.

 

Transmission Parts for Ford Dodge Jeep Toyota sells them for $25 plus shipping as part #200

see HERE

I did some research and learned that the Ford part number for the necessary flexplate is: EOAZ-6375A

That cross references to an 80 or 81 truck with a 351 and AOD.

So, tomorrow starts the AOD to C6 swap. Fortunately, I already have a Lokar kickdown on the C6 so it should connect up to the throttle body on my 89 van.

It never rains, but it pours. Beware mission creep, and do all your research before you start a project.

Again, thanks for your help Conanski. I do appreciate someone answering all my questions. Once I get this tranny straightened out, and get the brakes done, it should be a pretty fun van to drive.

 

the crownvictoria's came from the factory with a 5.8/AOD combo. thats the flexplate i got when i did my swap way back when. any parts store can get it, i would go this route personally. that way its for sure correct. i think i asked for an 88 or 89 model year.

you might think about your options here. either rebuild that AOD tough or spend about $400 less and get a smoken C6 built. granted you will loose OD but the tranny is by far stronger than that AOD. not to mention if you dont get the TV cable adjusted properly it will ruin even the new tranny fast.