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Engine 1986 mclaren capri will not run

  • Thread starter Thread starter MercRS
  • Start date Start date Jul 10, 2019

MercRS

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Jan 15, 2003
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Jul 10, 2019
#1
  • Jul 10, 2019
  • #1
86 mclaren capri 5.0 5spd
I followed the checklist it will not run it barely will idle at 50 rpm dies
If you rev motor it breaks up bad will not go past 2k rpm
New computer,had a good extra upper intake replaced vacuum lines
No codes iac is new nothing is working
The only way it runs if you pull vacuum to bap sensor (speed density)
Then it idles and revs fine but I think it runs rich with bap vacuum wide open leak.
The converter glows.
Checked injectors all good
 

MercRS

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Jan 15, 2003
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Chicago,IL
Jul 10, 2019
#2
  • Jul 10, 2019
  • #2
Was going to try new o2 sensors next
 

General karthief

wonder how much it would cost to ship you a pair
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#3
  • Jul 10, 2019
  • #3
Notice that I changed my post Changing the 02s will likely not help but get some new ones anyway, your gonna need them when you get it running right.
You didn't mention fuel pressure.
go back over the list, do it step by step.
any modifications?
 
Last edited: Jul 10, 2019

MercRS

Member
Jan 15, 2003
55
1
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Chicago,IL
Jul 11, 2019
#4
  • Jul 11, 2019
  • #4
No all stock
Fuel pressure is good
Replaced filter also
 

MercRS

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Jan 15, 2003
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Jul 11, 2019
#5
  • Jul 11, 2019
  • #5
When it runs with map vacuum off doesn’t that eliminate a lot
Makes no sense it will run with a giant vacuum leak
 

General karthief

wonder how much it would cost to ship you a pair
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Jul 11, 2019
#6
  • Jul 11, 2019
  • #6
Makes no sense it throws no codes.I
Does it have a maf swap?
 

Noobz347

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Jul 11, 2019
#7
  • Jul 11, 2019
  • #7
MercRS said:
86 mclaren capri 5.0 5spd
I followed the checklist it will not run it barely will idle at 50 rpm dies
If you rev motor it breaks up bad will not go past 2k rpm
New computer,had a good extra upper intake replaced vacuum lines
No codes iac is new nothing is working
The only way it runs if you pull vacuum to bap sensor (speed density)
Then it idles and revs fine but I think it runs rich with bap vacuum wide open leak.
The converter glows.
Checked injectors all good
Click to expand...


You say the car is speed density? Are you certain that you have the correct sensor installed? You should have a MAP for speed density:

1979-1993 Fox Body Mustang MAP & BAP Sensors - LMR.com

Vacuum pressure issues in your 1979-1993 Fox Body Mustang? Get replacement MAP & BAP sensors at 5.0 Resto. Your manifold absolute pressure sensors (MAP) and bar
lmr.com
 

Mustang5L5

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Jul 11, 2019
#8
  • Jul 11, 2019
  • #8
Noobz347 said:
You say the car is speed density? Are you certain that you have the correct sensor installed? You should have a MAP for speed density:

1979-1993 Fox Body Mustang MAP & BAP Sensors - LMR.com

Vacuum pressure issues in your 1979-1993 Fox Body Mustang? Get replacement MAP & BAP sensors at 5.0 Resto. Your manifold absolute pressure sensors (MAP) and bar
lmr.com
Click to expand...

Shouldn't matter. My MAF-swapped '88 is still using the original MAP with the vac line removed. Runs well


Glowing cat, and running better with MAP unplugged is a clue that something is up with the air/fuel mix. You should be at least getting a code for that though.

You are getting three code 11's? two with engine off, and one code 11 with engine running?
 
Last edited: Jul 11, 2019
Reactions: Noobz347

MercRS

Member
Jan 15, 2003
55
1
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Chicago,IL
Jul 11, 2019
#9
  • Jul 11, 2019
  • #9
Original sensor
How do you check ar fuel?
Thanks
 

MercRS

Member
Jan 15, 2003
55
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Chicago,IL
Jul 11, 2019
#10
  • Jul 11, 2019
  • #10
Had a extra ect sensor put that on nothing
Going to try fuel pressure regulator next
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
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Jul 11, 2019
#11
  • Jul 11, 2019
  • #11
You said fuel pressure is good, what is the pressure?
 

MercRS

Member
Jan 15, 2003
55
1
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Chicago,IL
Jul 11, 2019
#12
  • Jul 11, 2019
  • #12
I just tested at filter no pressure tester
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,902
10,555
203
polk county florida
Jul 11, 2019
#13
  • Jul 11, 2019
  • #13
MercRS said:
I just tested at filter no pressure tester
Click to expand...
not sure what that means?
 

MercRS

Member
Jan 15, 2003
55
1
8
Chicago,IL
Jul 11, 2019
#14
  • Jul 11, 2019
  • #14
It runs with map vacuum pulled off and a huge vacuum leak.
It will not run with it connected
It eliminates a few things I think
 

jrichker

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Jul 12, 2019
#15
  • Jul 12, 2019
  • #15
@MercRS

Dump codes sticky

Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. Codes may be present even if the CEL (Check Engine Light) isn’t on. You don’t need a code reader or scanner – all you need is a paper clip, or if your lady friend has a hair pin, that will do the job.
I highly suggest that you read it and follow the instructions to dump the codes. http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/
 
Last edited: Jul 12, 2019
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