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Got it started, now just working out bugs....

  • Thread starter Thread starter mbsprinks281
  • Start date Start date Feb 5, 2006

mbsprinks281

Member
Apr 19, 2005
58
2
9
Lockport, IL
Feb 5, 2006
#1
  • Feb 5, 2006
  • #1
Well, I did a whole top end and after getting it back together I couldnt get it started. After going over the much posted "No Start" list i FINALLY got it started.
So, heres what happened. I went over timing and the valve adjustment multiple times. Everything was done to a T. I Put it all back together and still nothing. It cranked but wouldnt start. I was getting seriously confused.
Anyway the most simple thing popped into my head. Compression????
So, I did the compression test and was getting 60 lb. readouts on all of the cyclinders. When I was bumping it over I had the fuel relay disconnected. What I figured was that the cyclinders must be washed out. So, I put a few drops of oil in each cylinder via the plug hole. I then put compressed air to each cylinder to see where the blow bye was. NONE!!!!
Put it back together and I had 100lb plus compression. Started it right up.
Now here is my question. The car wont stay running unless I hold the throttle around 1700 RPM. Think the timing is still a touch off or is the computer still trying to get used to the new hardware????
 

CobraStang95

Founding Member
Apr 9, 2002
84
0
7
New Jersey
Feb 5, 2006
#2
  • Feb 5, 2006
  • #2
I would check all vacuum hoses first, my car did the exact same thing and it was the vacuum hose that goes under the front of the intake.
 

Black1987Stang

Active Member
Aug 22, 2004
1,422
0
37
Jersey Shore
Feb 5, 2006
#3
  • Feb 5, 2006
  • #3
mbsprinks281 said:
Well, I did a whole top end and after getting it back together I couldnt get it started. After going over the much posted "No Start" list i FINALLY got it started.
So, heres what happened. I went over timing and the valve adjustment multiple times. Everything was done to a T. I Put it all back together and still nothing. It cranked but wouldnt start. I was getting seriously confused.
Anyway the most simple thing popped into my head. Compression????
So, I did the compression test and was getting 60 lb. readouts on all of the cyclinders. When I was bumping it over I had the fuel relay disconnected. What I figured was that the cyclinders must be washed out. So, I put a few drops of oil in each cylinder via the plug hole. I then put compressed air to each cylinder to see where the blow bye was. NONE!!!!
Put it back together and I had 100lb plus compression. Started it right up.
Now here is my question. The car wont stay running unless I hold the throttle around 1700 RPM. Think the timing is still a touch off or is the computer still trying to get used to the new hardware????
Click to expand...


60psi? then add oil and it went up to 100psi? I would say its a ring problem but im sure it ran fine before the swap and all of them couldnt go all at the same time. Just curious when u did the compression test did u open the throttle plate all the way? if not that might be why ur numbers are lower and when u added the air that might have brought it up to 100psi. Either that or your valve geometry is wayy offf. When i redid my heads i had to add shims to the stock rockers cuz i was getting like 10 psi of compression in some cylinder, i added the appropriate shims and i had full compression. Sounds like ur rockers are stud mount, what did u set the valve lash too, 1/4 turn, 1/2 turn? Or could be from wrong size pushrods but idk. Hows the timing, firing order, tps, sounds like maybe a vacuum leak too.
 

mbsprinks281

Member
Apr 19, 2005
58
2
9
Lockport, IL
Feb 6, 2006
#4
  • Feb 6, 2006
  • #4
ttt
 

Zero_chance

Founding Member
May 29, 2001
1,244
7
59
Maricopa, AZ
Feb 6, 2006
#5
  • Feb 6, 2006
  • #5
Yeah 60 in every cylinder seems a bit low. I think stangdiddles barking up the right tree..... did you have the throttle plate open or closed when you got the initial 60 psi reading?
 

jrichker

StangNet's favorite TOOL
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Mar 10, 2000
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Dublin GA
Feb 6, 2006
#6
  • Feb 6, 2006
  • #6
Compression checks on a cold engine can give all sorts of crazy results.

Redo the compression test on a warm engine and you may even get a warm fuzzy feeling about the results...
 
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