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Chris (aka-Moose)
Chris (aka-Moose), RV Mechanic
Category: RV
Satisfied Customers: 43873
Experience:  16 years of experience
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I have a 1997 holiday rambler with a 460ci efi motor that

Customer Question

i have a 1997 holiday rambler with a 460ci efi motor that wont start unless i put carb spray down the throtle body. once it fires the injectors do pulse, i dont know what it could be?
JA: Will the headlights turn on? Is the battery fully charged?
Customer: yes it turns over fine but wont start without carb spray
JA: What is the model of your '97 Rambler?
Customer: vacationer
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: i have not yet
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 1 month ago.
Category: RV
Expert:  Chris (aka-Moose) replied 1 month ago.

Welcome, I'm Chris (aka Moose) I prefer to work when others don't, I am here around lunch and after dinner till after midnight.

When trying to start does it crank slow?

Is there exhaust smoke briefly after startup?

Must you do this every time started hot or cold?

Customer: replied 1 month ago.
it cranks just fine just wont start unless carb spray is sprayed down the throtle body and then i get the injector pulse
Customer: replied 1 month ago.
Expert:  Chris (aka-Moose) replied 1 month ago.

So you have confirmed there is no injector pulse when tested with a noid light when cranking the engine?

Will it start at full throttle with out the spray?

Customer: replied 1 month ago.
no injector pulse until it starts.and will not start at full throttle.
Expert:  Chris (aka-Moose) replied 1 month ago.


No pulse means your computer is not getting a CMP signal at cranking speed. For some reason the engine has to be going faster for the CMP starts reading. I would replace the cam sensor and sand the mounting surface to make sure it is as close to the timing gear as possible.

This is my 1st answer, but does not have to be my only answer. You the website and myself expect you to have a ~~~5 STAR EXCELLENT~~~ experience with my help. Please let me know if you are pleased by selecting a star rating above or by replying and saying your pleased. Not rating or rating 1-2 stars does not benefit you nor me in any way. Follow up and reply as often and when needed, there is no extra charge to do so.

Thanks Moose.

Expert:  Chris (aka-Moose) replied 1 month ago.

Hello again Chris here,

  • I am following up with you to see if you got everything you needed from my answer. We're you pleased with my help?
  • If you were not pleased with my help, please let me know by replying so I can help more.
  • This post is coming up on the 7 day mark where it times out. When a post times out, that means it's no longer on my active list (you reply and I may never know it.)

Thanks Chris

Customer: replied 1 month ago.
no there is not a cam sensor at the timing gear.i ended up un pluging the throttle position sensor and it started, so i replaced the throttle position sensor and it starts now.
Expert:  Chris (aka-Moose) replied 1 month ago.

Thanks for letting me know. I have never heard of no injector pulse from a TP sensor and this engine to not have a cam sensor.