ECU bad? - Defender Source
Defender Source  

Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions


Reply
 
Thread Tools
  #1  
Old February 7th, 2012, 06:17 PM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
ECU bad?

So, my rebuild is to the point that I want to start the engine, but it won't. I've got spark so I think its fuel related.

With ignition switch in II position, the fuel pump runs for about 5 seconds, I've got pressure at the fuel rail, but I don't think the injectors are firing. I put a 12v bulb across one of them and nothing when I crank.

When I short pin 11 or 13 to ground on the ECU I get a nice squirt of fuel out of the injectors.

The ECU is turning on the fuel pump initially and throws code 02 when disconnected, so maybe its OK? Is it looking for some other signal (maybe RPM) before firing the injectors? According to the wiring diagram, pin 39 is connected to the ignition coil. Is this where it gets its RPM signal? Any other sensors that would prevent it from firing the injectors?
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old February 7th, 2012, 06:58 PM
rijosho's Avatar
rijosho
Status: Offline
Joshua
1995 Black ST - Rhinolined edition
Research Assistant/Eagle Eyes
 
Join Date: Apr 2009
Location: NYC
Posts: 16,557
Registry
coil?
__________________
Quote:
I am talking purely from an aesthetics standpoint.
Reply With Quote
  #3  
Old February 7th, 2012, 11:23 PM
evilfij's Avatar
evilfij
Status: Offline
evilfij
I have never seen a rover in person
Member
 
Join Date: Oct 2003
Location: on the internet
Posts: 14,688
Silver relay. It could also be the ignition MODULE on the side of the distributor or on a plate near the coil (if it has been relocated).

My money is on the relay, but I had the module go bad from a short on chicky. You can check the relay by swapping them and if the fuel pump does not run when swapped, then it is the relay.
__________________
*not legal advice*
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old February 7th, 2012, 11:28 PM
J. Andrew's Avatar
J. Andrew
Status: Offline
J. Andrew
95 D90 NAS SW #384
Member
 
Join Date: Feb 2010
Location: New Orleans
Posts: 136
He could swap the two silver relays, and if the fuel pump then doesn't come on, than thats prob the culprit right?
Reply With Quote
  #5  
Old February 7th, 2012, 11:31 PM
evilfij's Avatar
evilfij
Status: Offline
evilfij
I have never seen a rover in person
Member
 
Join Date: Oct 2003
Location: on the internet
Posts: 14,688
Yup. I was editing while you posted.
__________________
*not legal advice*
Reply With Quote
  #6  
Old February 8th, 2012, 07:24 AM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
Both silver relays are fine. I have 12v on the injectors, but when cranking, the ECU is not pulling them to ground so they don't fire (squirt). Either the ECU is bad or it's waiting for some other signal, like rpm maybe?

I'm getting a good strong spark at the right time so I don't think it's the coil or ignition module (amplifier). I can't figure out how the ECU gets an RPM signal.
Reply With Quote
  #7  
Old February 8th, 2012, 07:40 AM
o2batsea's Avatar
o2batsea
Status: Offline
Bill Adams
66 109 sw 94 lwb
Member
 
Join Date: Jul 2009
Location: kensington md
Posts: 6,506
Registry
Are you sure that you timed off #1 and it was on the compression stroke? #1 is the left front piston, not the right front like you'd expect. It is very easy to miss this and chase a ton of other things that are not the problem. Done this myself so many times.
If it was OK when you pulled the engine out, then the ECU is probably still OK now.

Go back, recheck everything one more time. Something obvious is staring you in the face and you aren't seeing it.

I will admit that the Lucas 14CUX has a nasty tendency to drop a bank without prior warning. It could be the ECU, but that would be my last resort after rechecking everything else
__________________
Bill Adams

1966 109 5 door wagon 300Tdi "spermaceti fueled"
1994 RRC LeWiB "ruining the air behind me"
1968 2A 88

All my troubles are Rover
Reply With Quote
  #8  
Old February 8th, 2012, 08:08 AM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
I'm pretty sure I got the timing right, but even if it wasn't, that wouldn't explain why the injectors are not firing.

It probably is something really obvious. My guess at this point is that the ECU is not getting an RPM signal, but I can't figure out where it gets it from and what type of signal it is (pulse or 0-5v)? From the wiring diagram I found, pin 39 on the ECU is connected to the coil, my guess is this might be the rpm signal, but I don't have any wires on the coil that go back to the ECU.
Reply With Quote
  #9  
Old February 8th, 2012, 08:49 AM
o2batsea's Avatar
o2batsea
Status: Offline
Bill Adams
66 109 sw 94 lwb
Member
 
Join Date: Jul 2009
Location: kensington md
Posts: 6,506
Registry
Pretty sure this comes from the ignition amplifier module.
__________________
Bill Adams

1966 109 5 door wagon 300Tdi "spermaceti fueled"
1994 RRC LeWiB "ruining the air behind me"
1968 2A 88

All my troubles are Rover
Reply With Quote
  #10  
Old February 8th, 2012, 12:12 PM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
There are only 2 connections to the amplifier, 1 goes to the positive terminal on the coil and the other goes to the negative. Unless I'm missing a wire, there's nothing between the amplifier and the ECU.
Reply With Quote
  #11  
Old February 8th, 2012, 12:30 PM
o2batsea's Avatar
o2batsea
Status: Offline
Bill Adams
66 109 sw 94 lwb
Member
 
Join Date: Jul 2009
Location: kensington md
Posts: 6,506
Registry
I think there's a wire from the neg side of the coil to the ecu. Thus, timing is from amp.
__________________
Bill Adams

1966 109 5 door wagon 300Tdi "spermaceti fueled"
1994 RRC LeWiB "ruining the air behind me"
1968 2A 88

All my troubles are Rover
Reply With Quote
  #12  
Old February 8th, 2012, 12:34 PM
Grover's Avatar
Grover
Status: Offline
Mike
Birmabright Bread Box/Swagger Wagon
Member
 
Join Date: Dec 2005
Location: Cincinnati, Ohio
Posts: 1,857
Registry
I delt with ignition issues last summer. IIRC, there is a white wire that connects to the coil (can't remember + or -) that triggers the ECU to fire the injectors. See pic...
Good luck...

Cheers...
Attached Thumbnails
Click image for larger version

Name:	DSC00329_resized.jpg
Views:	84
Size:	158.1 KB
ID:	47196  
__________________
LR3 sidesteps with rocker panels for sale $400


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote
  #13  
Old February 8th, 2012, 01:22 PM
evilfij's Avatar
evilfij
Status: Offline
evilfij
I have never seen a rover in person
Member
 
Join Date: Oct 2003
Location: on the internet
Posts: 14,688
Also check the "chicklet"

Search and you will see what I am talking about.
__________________
*not legal advice*
Reply With Quote
  #14  
Old February 8th, 2012, 01:44 PM
cgalpin's Avatar
cgalpin
Status: Offline
Charles Galpin
'94 D90 ST, '63 SeriesIIA
Site Team
 
Join Date: Jan 2004
Location: South Riding, VA
Posts: 11,625
Registry
It's the thing taped up in the wiring going to the MAF
__________________
Quote:
Originally Posted by pendy
I'm here for the D's
Reply With Quote
  #15  
Old February 8th, 2012, 03:28 PM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
Thanks for the photo but it's too dark to see anything. How many wires do you have on the positive and negative terminals?

I had checked the "chicklet" before and got something like 6.8K ohms, it wasn't a dead short or an open so I figured it was ok, I'll search to see what value it should be.
Reply With Quote
  #16  
Old February 8th, 2012, 05:36 PM
Grover's Avatar
Grover
Status: Offline
Mike
Birmabright Bread Box/Swagger Wagon
Member
 
Join Date: Dec 2005
Location: Cincinnati, Ohio
Posts: 1,857
Registry
I'll get a better picture tonight...
__________________
LR3 sidesteps with rocker panels for sale $400


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote
  #17  
Old February 8th, 2012, 08:20 PM
Grover's Avatar
Grover
Status: Offline
Mike
Birmabright Bread Box/Swagger Wagon
Member
 
Join Date: Dec 2005
Location: Cincinnati, Ohio
Posts: 1,857
Registry
There is a white wire coming from the MAF loom to the (-) side of the coil.

Can you take a pic of your setup?
__________________
LR3 sidesteps with rocker panels for sale $400


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote
  #18  
Old February 10th, 2012, 08:53 AM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
Here's my coil....



Click image for larger version

Name:	image-3158153405.jpg
Views:	81
Size:	416.1 KB
ID:	47286
Reply With Quote
  #19  
Old February 10th, 2012, 11:55 AM
Grover's Avatar
Grover
Status: Offline
Mike
Birmabright Bread Box/Swagger Wagon
Member
 
Join Date: Dec 2005
Location: Cincinnati, Ohio
Posts: 1,857
Registry
is your ign mod located on the dizzy?
__________________
LR3 sidesteps with rocker panels for sale $400


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote
  #20  
Old February 10th, 2012, 12:06 PM
MAX711's Avatar
MAX711
Status: Offline
Andrew Dance
1994 D-90 ST
Member
 
Join Date: Jun 2009
Location: Las Vegas, NV
Posts: 114
Yes it is. 2 wires going to it, one to the positive and 1 to the negative on the coil.

I've traced one side of the "chicklet" to pin 39 on the ECU. The other side disappears into the harness and I can't see where it goes. I think I might try a jumper from this to the positive on the coil and see what happens.
Reply With Quote
Reply

Lower Navigation
Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions

Tags
ecu

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need Help For Bad Handling...(I mean BAD!) Cube II Defender Technical Discussions 18 July 7th, 2006 09:07 AM
Speed Sensor and ECU Issues DJ Menasco Defender Technical Discussions 14 February 16th, 2006 08:45 PM
Interface on '94 ECU (OBD-I?) jaherring Defender Technical Discussions 10 October 11th, 2005 10:06 PM
Where did you put your ECU jcasteel Defender Technical Discussions 6 January 12th, 2005 11:31 AM
bad bad BAD noise rover4x4 Defender Technical Discussions 11 December 12th, 2003 12:44 AM


All times are GMT -5. The time now is 08:45 PM.


Copyright