V8 Miata Wiring, Electrical, and ECUs v8 conversions on a Miata can be tricky. Post your comments or questions within with regards to swap wiring and electrical.

Anyone make a Ford ECU Extension Harness?

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 04-13-2015, 06:55 PM
  #1  
V8 Miata Fan
Thread Starter
 
norotors's Avatar
 
Join Date: Jan 2015
Location: Central NC
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default Anyone make a Ford ECU Extension Harness?

My car is a NA with a EFI 5.0 Ford in it. The ECU is mounted in the stock location under the passenger side floor/firewall. I am having a problem with the car shutting off after it gets thoroughly hot (after about an hour or so of driving). I am thinking it may be the ECU getting hot, and I'd like move it to underneath the passenger seat.

Does anyone know of someone that makes an extension wiring harness that plugs into the ECU plug then into the ECU so I can move it without splicing wires?
Old 04-14-2015, 07:20 AM
  #2  
V8 Miata Zealot
 
tbone heller's Avatar
 
Join Date: Mar 2010
Location: Canton, Georgia
Posts: 1,206
Received 48 Likes on 45 Posts
Default

Have you tried laying the ECU on top of the passenger footwell carpet & driving to see if that is the problem?
Old 04-14-2015, 08:46 AM
  #3  
V8 Miata Participant
 
V8MiataMike's Avatar
 
Join Date: Nov 2014
Location: Atlanta, Ga
Posts: 296
Likes: 0
Received 12 Likes on 11 Posts
Default

+1 on tbone's suggestion for sure.

Also, what about that TFI on the distributor thing. I've seen many cases were it creates intermittent problems.

My experience with ECUs has been they are either good or bad...
Old 04-14-2015, 08:55 AM
  #4  
V8 Miata Fan
Thread Starter
 
norotors's Avatar
 
Join Date: Jan 2015
Location: Central NC
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default

I am planning on pulling the ECU out of its hole out on to the floor and driving it some this weekend.

I am also pursuing moving the TFI module. I've seen MRM's kit to move it. Are those still available?
Old 04-14-2015, 06:29 PM
  #5  
V8 Miata Fan
 
brendabrown's Avatar
 
Join Date: Sep 2011
Posts: 28
Received 0 Likes on 0 Posts
Default

It could also be that your fuel line is to close to the header and the fuel boils and will not start until it cools down. Just a thought.
Old 04-14-2015, 09:53 PM
  #6  
V8 Miata Fanatic
 
MX-Brad's Avatar
 
Join Date: Mar 2014
Location: SW Ont.
Posts: 635
Received 37 Likes on 32 Posts
Default

...or starter heat soak.
Old 04-16-2015, 12:00 AM
  #7  
Administrator
 
MRM331's Avatar
 
Join Date: Nov 2009
Location: Allentown, PA
Posts: 1,120
Likes: 0
Received 38 Likes on 32 Posts
Default

What you're talking about sounds like the TFI. I have one kit in stock currently but probably will not have any more made up until next week.

When I went with a plug-n-play MS2 I extended it's adapter harness to relocate it behind the passenger seat. You could do this using the female plug from an old ECU, a project box from RadioShack and a used male ecu plug. Unfortunately no one makes an extension harness for 60-pin Ford ecu's.

Starter heat soak and hot fuel will not shut the car down, only keep it from restarting until it cools.

-Jason
Old 04-16-2015, 08:15 AM
  #8  
V8 Miata Fanatic
 
MX-Brad's Avatar
 
Join Date: Mar 2014
Location: SW Ont.
Posts: 635
Received 37 Likes on 32 Posts
Default

Right. I misread that, thinking it was a hot start issue.
Old 04-16-2015, 08:03 PM
  #9  
Administrator
 
MRM331's Avatar
 
Join Date: Nov 2009
Location: Allentown, PA
Posts: 1,120
Likes: 0
Received 38 Likes on 32 Posts
Default

I've been asked about making these before so I did a little research:

First I thought I could buy a MS2-Ford adapter harness from DIYAutoTune and modify the MS end to mate with a Ford processor. This would have been very easy and economical, unfortunately they do not make them any more.

Then I found a guy on eBay who makes them with a recycled ECU plug on one end and a 3d printed harness plug on the other. He wants $200 for a two foot long extension harness and $20 for each additional foot.

Using that as a guide I figure I can do the same using a recycled harness plug and only extending wires for the specific car to keep costs down. I think I can make a 5' one for about $150.

So...new a new MRM product is born. 5' Ford EEC-IV extension harnesses for $150 + S/H. Any takers? PM me if interested.

-Jason
Old 04-16-2015, 08:12 PM
  #10  
V8 Miata Fan
Thread Starter
 
norotors's Avatar
 
Join Date: Jan 2015
Location: Central NC
Posts: 36
Likes: 0
Received 0 Likes on 0 Posts
Default

Let's not forget the fuel is at 38-40 PSI. The boiling point gasoline at 40 psi - I don't know, but at that temperature I would be more concerned with it exploding than vapor locking. At 6-8 PSI in a carbureted application, vapor lock is a possibility, but not too likely in an EFI application.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
577nitro
Ford V8 Discussion
6
06-04-2015 02:44 PM
orion4096
Parts For Sale
7
03-30-2015 08:05 AM
LizardKing
Wanted to Buy - Parts
2
02-25-2015 01:44 PM
MX-Brad
V8 Miata Wiring, Electrical, and ECUs
2
02-03-2015 08:17 AM
clos561
V8 Miata Wiring, Electrical, and ECUs
3
09-09-2010 03:30 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Anyone make a Ford ECU Extension Harness?



All times are GMT -5. The time now is 06:14 AM.