Fuel Injection, (starting problem)
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Fuel Injection, (starting problem)
So exactly when did you do that pressure test? Was it "after it sits overnight or for a long while", or was it "after it cranks the first time"? You need to to make SURE you're testing it WHILE it's exhibiting the fault. I'd put a FP gauge on it one evening, pull one spark plug OUT, insert a compression tester, and put a spark gap tester on that plug's wire (or lay the plug on the block). Arrange the gauges so you can see them WHILE it's cranking, and the next morning, try it. If it cranks right up (coughing from the 1 dead cylinder), you won't learn anything. But if it cranks for a while, look at the gauges and the spark to see what's wrong.
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Posting Guru
Joined: Jul 2003
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From: Independence, MO
Fuel Injection, (starting problem)
it' got a fresh tune up, that didn't affect it at all, I know i gapped the plugs right, the fuel pressure test were done with the engine barely warm, and i did them according to the haynes book, the fuel pressure dosent leak down right a way, it takes an hour are so, is this about normal, the book say 5psi in 1 min. but as soon as you switch the key on the pressure jumps right back to 40psi. I'm missing something here.
Thnx DW
Thnx DW
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Posting Guru
Joined: Jul 2003
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From: Independence, MO
Fuel Injection, (starting problem)
If all the pressure test prove okay, could it be the
TFI mod. on the distr.? an ignition problem isted of fuel? when you switch the key on and it has 40psi then it should fire up, I was kinda under the impresion that the TFI mod. eithr worked or not, Do you know differently? DW
TFI mod. on the distr.? an ignition problem isted of fuel? when you switch the key on and it has 40psi then it should fire up, I was kinda under the impresion that the TFI mod. eithr worked or not, Do you know differently? DW
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Fuel Injection, (starting problem)
Yes, it could be anything - that's why I suggested testing everything at once tomorrow morning. If it's not sparking, you'll see it on the gap tester (or spark plug if you do it that way). For any gas engine to run, you need:
air & gasoline (in the proper proportion)
compression
spark (at the right time)
You have to figure out WHICH of those you don't have and WHY it only fails in the morning.
air & gasoline (in the proper proportion)
compression
spark (at the right time)
You have to figure out WHICH of those you don't have and WHY it only fails in the morning.
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Posting Guru
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From: Independence, MO
Fuel Injection, (starting problem)
Okay i'll do a cold compresion test and everything else first am i get, if i have the gas prssure onthe rail is there anything else in the injection system that would cause it? DW
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Fuel Injection, (starting problem)
Sure. The injectors may not be opening, or not long enough to get the right mix.
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Posting Guru
Joined: Jul 2003
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From: Independence, MO
Fuel Injection, (starting problem)
would that be in the ECM? or just bad injectors? The engine run like a top, its just after it sits a long while it acts like and old carb motor that has to spin a few times while you pump the gas peddle to crank it up, once it fires up you shut it off and crank it all day, unless it sits for a long time. but like i said the fuel pressure is there, i can deal with the older motors but i'm struggling to learn this injection stuff! 
Thnx for any help DW
Thnx for any help DW
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Fuel Injection, (starting problem)
I dunno - do the test tomorrow morning and go from there. You should NEVER press the gas pedal while cranking. If the engine is somehow flooded, you can hold the pedal to the floor until you clear the flood, but NEVER pat the pedal or hold it at any mid-throttle position. The engine should start by just turning the key.
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Joined: Jan 2003
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Fuel Injection, (starting problem)
However, it starts quick when I do the following:
I crank it over momentarily, then give the gas pedal 2 pumps, then crank again and it fires up right away....
I'm suspecting that it's a worn throttle position sensor; but I'm not sure.
Thought I'd share in case you want to try it.
I crank it over momentarily, then give the gas pedal 2 pumps, then crank again and it fires up right away....
I'm suspecting that it's a worn throttle position sensor; but I'm not sure.
Thought I'd share in case you want to try it.
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