Non-H.O. 5.0 questions

Drew0569 · 04-12-2011, 09:59 AM

I've got a 5.0 out of a '90 Crown Victoria and am planning to put it (EEC-IV fuel injection and all) into my '79 Fairmont.
I have a couple of questions:
1) I remember reading and/or being told many years ago that the pressure-density systems didn't benefit much, if any, from any improvements that make the engine breathe better (i.e., aftermarket heads, headers, intake manifolds, etc.). Is this a strict fact, a statement that depends on specifics, or straight-up wrong?
2) Last night, I was weighing the possibility of using an aftermarket EGR-delete plate in place of the EGR spacer when I noticed that there are coolant lines connected to the spacer on the side opposite the EGR valve. What is the purpose of the coolant connections and is there some benefit (or detriment) in disconnecting them from the EGR spacer?
I've decided that I'll likely leave the stock spacer in place and install the EGR valve block-off plate that I already bought. At least, that's my plan for now...
By the way, I'm fortunate in that the state in which I live doesn't require any smog testing of cars as old as mine, so anything you may have to suggest with that fact in mind would be appreciated.
Thank you.

phantom · 04-12-2011, 11:03 AM

90 has a mass air flow sensor and it does well with aftermarket parts,cams heads etc. Map sensor vehicles not so well.

the coolant is not as hot as egr gasses,that being said I dont feel you will get any noticable gains with an egr block off plate.It could set an cel due to lack of flow.

Drew0569 · 04-12-2011, 11:23 AM

Actually, the non-H.O. 5.0's seem to have kept their MAP sensors after the H.O. engines got MAF sensors (i.e., the Mustangs)... at least that's the case the Crown Vics.
Please note that I said that I'm deleting the EGR valve. I've already purchased all the necessary pieces from RJM injection (all the correct resistors, etc.). So the exhaust gases won't be a factor. Without any exhaust gases flowing through the EGR spacer, will the engine coolant cool the intake air or will it heat up the intake air when the EGR valve gets replaced by a block-off plate?

Canuck623 · 04-12-2011, 12:12 PM

When you delete the EGR your head temps go up and it may cause it to ping. Backing up the timing may help with that but it will negate any gains made from deleting it. With a MAP anything that lowers the intake vacuum, cams etc., will have an adverse affect on performance.

Drew0569 · 04-12-2011, 02:14 PM

Why do head temperatures go up when the EGR valve is removed? Why would this not happen with a MAF-equipped engine? Is there anything that can be done to prevent pinging other than advancing the timing? Would using premium gas exclusively (which I already do anyhow) help? What about an electric fan and a thermostat with a lower opening temperature? I can convert to MAF, but that will add to the expense and complexity of the installation.

Canuck623 · 04-12-2011, 03:17 PM

Sorry, you misunderstood. The issue with the EGR is on everything. The MAP systems are just harder to tune is all. The head temps rise because the cylinders are not being quenched with the exhaust gasses. You would need an engineer to explain it all, I am just a tech that knows it happens.

Dominick · 04-12-2011, 05:15 PM

Here is an article you may read
Ford Fuel Injection

Drew0569 · 04-13-2011, 07:28 AM

Thanks, Dominick. I know about that website and had failed to consult the wealth of information therein.
I took another look at their "EEC Program Codes" page, which lists all of the different ECU's by code number, engine displacement, and vehicle(s) in which a particular ECU was installed. The list confirmed my statement that the Crown Victoria didn't go to MAF for all cars until 1991. Prior to that, they had been speed-density systems for "49-states and Canada" cars and MAF systems for California cars. From 1992 and following, Ford used the 4.6-liter engine.
Anyhow, I think I'll avoid some potential tuning problems by converting over to MAF. According to my '90 Crown EVTM pin-out, I'll have to move six pins to different terminals on the ECU connector and install five new wires... or I might skip that plan and simply buy a '91 Crown Vic wiring harness and ECU.

Jonzo77 · 04-13-2011, 11:02 AM

it's funny because i was gonna post the same link dom did, but then i saw he did it. phantom, MAF wasn't put on all cars till 91. trust me i just did a conversion in an 89 crown vic. and decided to go back to speed density, because i didn't need the mass air system. of course all you need to do is swap the injectors with 19#, and put a 351W cam in, oh and of course the computer from a lincoln mk7, thunderbird, cougar... Fords Unlimited Car Club / Tech Info / Speed Density to Mass Air Conversion

to make it a real HO, it would also need the upper plenum, and the E7TE heads, but...

Drew0569 · 04-17-2011, 01:18 PM

I'm sticking to the Crown Vic engine controls at this point, so I'm trying to obtain the correct ECU. Since I'm going to MAF, this means I'll need a '91 Crown Vic ECM.
Thanks to an ebay Ford part number decoding article (eBay Guides - The Ford Part Numbering system - How to decode) and Rock Auto Parts' website, I've been able to narrow down the part number to: F0AZ-12A650-BA, F0AZ-12A650-BB, F0AZ-12A650-CA, F0AZ-12A650-CB, F1AZ-12A650-AA, F1AZ-12A650-BA, or F1AZ-12A650-CA. Can any of you provide some insight to zero in on the part number I'll need or at least narrow the field? Thanks!

Jonzo77 · 04-22-2011, 09:21 PM

http://www.fordfuelinjection.com/?p=17

the code you'd be looking more specifically for is located on the ID sticker like they show on the sight.
LOX2 is the one you want. it's basically a calibration code. in 91 all EEC4 computers were made for 50 state emissions, no exceptions, this is still true with the EEC5, and i'm not sure if they have a 6 or not yet...
basically you're on the right track.