won't start need help
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Senior User
Joined: Jan 2003
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From: East Texas
won't start need help
I have a 90 F150 4.9L The engine will turn over, but won't start. I have replaced the fuel pump relay and the ignition control module. Neither have helped, a friend said it could be coil, or coil pickup. any ideas or suggestions?
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Joined: Sep 2003
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From: ricelake wi
300 wont start
I would love to help you but I am currently having the same problem on an 88 f-150 4.9 I have replaced the moduals inside and outside the distributer and the coil retimed it new cap and rotor plenty of spark and fires with starting fluid but will backfire through throttle body If you can figure this out please let me know
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Joined: Sep 2003
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From: ricelake wi
I'm assuming you must have narrowed it down to ignition problems you might want to chck for fuel problems there are two relays on the drivers side for your fuel pumps when you turn the key on they should clik there might only be one if you only have one tank they are right next to the air box check those that was the problem on my 88 also check wires to them mine was caroded by the firewall:
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Joined: Aug 2003
Posts: 231
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From: Gaffney, SC
Shaun,
Rough idle and surging sounds like a vacuum leak to me. These are hard to spot, but here is how I would proceed.
First, check the big stuff: cracks on your air intake, etc. Remove your air intake components, turn them over, and look for any splits or punctures. If you find them, patch them or replace them.
Secondly, and if the first step did not solve the problem, examine all the little air hoses under the hood. Look for cracked junctions, disconnected hoses, and broken or punctured hoses. Sometimes you can hear an air leak, but it is difficult unless your motor idles very quietly. You will probably have to remove these hoses one at a time with the engine running, examining them closely and listening for changes in idle speed, to help you discover the source of the leak.
Hope this helps...
Firebug,
Engines basically need fuel and spark (not to insult your intelligence, just to say your post is a little ambiguous.) If, like Shaun, starting fluid will cause your truck to fire, then you probably have a fuel problem. If it won't, you likely have an electric problem. Pull a wire, crank the truck, and see if you're getting a spark. Let us know....
-Luke
Rough idle and surging sounds like a vacuum leak to me. These are hard to spot, but here is how I would proceed.
First, check the big stuff: cracks on your air intake, etc. Remove your air intake components, turn them over, and look for any splits or punctures. If you find them, patch them or replace them.
Secondly, and if the first step did not solve the problem, examine all the little air hoses under the hood. Look for cracked junctions, disconnected hoses, and broken or punctured hoses. Sometimes you can hear an air leak, but it is difficult unless your motor idles very quietly. You will probably have to remove these hoses one at a time with the engine running, examining them closely and listening for changes in idle speed, to help you discover the source of the leak.
Hope this helps...
Firebug,
Engines basically need fuel and spark (not to insult your intelligence, just to say your post is a little ambiguous.) If, like Shaun, starting fluid will cause your truck to fire, then you probably have a fuel problem. If it won't, you likely have an electric problem. Pull a wire, crank the truck, and see if you're getting a spark. Let us know....
-Luke
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Joined: Sep 2003
Posts: 18
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From: ricelake wi
the truck has plenty of spark we replaced everything in andon the distributor and a new coil I think I am on to something though it might just be the high pressure fuel pump on the frame rail acording to my chltons manual there should be 50to 60 lbs of pressure and when I unhooked the line in front of the filter it only shot out about a foot I am going to check into it today I am also going to check the valve train someone suggested a broken cam I will post what I find maybe It will help others
