Genius Mechanic needed!

A

alaska907

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Jun 29, 2008
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Alright so I have a 97 12 valve its a 5 spd. I recently just put some sdx stage 2's in and now my truck wont drive . It has a rough start then idles perfectly fine and i can rev up all i want, but as soon as I put a load on it feels like it starves for fuel. Ive done the fuel heater delete, changes all my filters, pulled the fuel sending unit looked at that seems to be fine. What I dont get is my truck ran great before i changed the injectors? Why would it start sucking air out of no where? Ive even blew out the lines from the back of the injection pump to the tank. Last but not least ive changed the lift pump twice. Please guys im 16 and no Mechanic in Alaska knows what their doing...
 
I have a 97 12 valve 5 spd. I recently just put some sdx stage 2's in and my truck was rough to start as usuall. Well I bleed all the lines got it running now my truck will idle amazing and as long as i want but when i put a load on the engine it acts like it's starving for fuel. Ive done everything I can think of as far as leaks or fuel pressure. I changed my lift pump, all my filters fuel prefilter and did the fuel heater delete. I got a new tork tek overflow valve . What I dont get is what could possibly do that after changing the injectors. Please guys Im 16 and can't find mechanic in Alaska that seems to know what their doing. Thank you guys all help would be appreciated!
 
Were the injectors used? When something causes a problem, you usually "undo" it before looking else where. Could be getting air from the injector return lines, but what do I know...
 
have you modified the afc? had a similar problem with a gentleman's truck this weekend and all it took was some pre boost fuel and it woke right up.
 
pretty sure they are brand new ordered them directly though sdx and yes, I have played with the afc and pre boost fuel?
 
I replace the rubber lines from the lift pump and the rubber lines untill they turn into hardlines on the way back to the tank
 
JWhite said:
Were the injectors used? When something causes a problem, you usually "undo" it before looking else where. Could be getting air from the injector return lines, but what do I know...
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Follow this man's advice. Put the stockers in that were good, and see if you get the issue. New doesn't mean good, might have a defect from the manufacturer.
 
I dont have my stock injectors anymore I sent them in for the core charge. Its related to air in the fuel sytem I think because its blowing white smoke.. The other thing is when I put my injectors in they gave me 15 spacers in 3 different sizes how many do I use?
 
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Have you modified the overflow valve, or at least checked to see where your fuel pressure hovers at idle and then again at 2500 rpm free rev?
 
alaska907 said:
I dont have my stock injectors anymore I sent them in for the core charge. Its related to air in the fuel sytem I think because its blowing white smoke.. The other thing is when I put my injectors in they gave me 15 spacers in 3 different sizes how many do I use?
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You use one "spacer" or copper washer as they are commonly referred to on the internet forums, per injector. You need to use the same size washer on all the injectors, and for a mostly stock truck with stock timing, the medium thickness "spacer" will work perfectly.
 
Big Blue24 said:
You use one "spacer" or copper washer as they are commonly referred to on the internet forums, per injector. You need to use the same size washer on all the injectors, and for a mostly stock truck with stock timing, the medium thickness "spacer" will work perfectly.
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I got a new overflow valve a Tork Tek .20 its set stock at 22 psi and my guage is bounceing between 5-10 psi
 
It would appear you do not need a genius mechanic, nor different injectors, however a clue would go a long way.
 
If you only have 5-10 psi at idle, do one last test.

Use a pair of vice grips and pinch the return line coming off of the injection pump and see if it changes the idle psi. If it goes up to 30-50 psi, your overflow valve is bad and it needs to be addressed. If it doesn't go up to 40+ psi, and you're sure you have a new clean fuel filter, clean prescreen bowl, clean heater, and clear suction lines all the way back to tank, you have one of two problems:

1. Your mechanical lift pump is toast and you need to install a new one $100.

2. You wiped out the pump lobe on the stock cam and need to either buy an electric pump setup $550, or buy a new cam $650 and $800 labor to install it.


I agree with roachie, your problem is 100% related to your low lift pump pressure.
 
Big Blue24 said:
If you only have 5-10 psi at idle, do one last test.

Use a pair of vice grips and pinch the return line coming off of the injection pump and see if it changes the idle psi. If it goes up to 30-50 psi, your overflow valve is bad and it needs to be addressed. If it doesn't go up to 40+ psi, and you're sure you have a new clean fuel filter, clean prescreen bowl, clean heater, and clear suction lines all the way back to tank, you have one of two problems:
I got a new overflow valve a little bit ago from Tork Tek .20 I think its called and its set stock for 22-23 psi.

1. Your mechanical lift pump is toast and you need to install a new one $100.
I just replaced the lift pump so that should be good.

2. You wiped out the pump lobe on the stock cam and need to either buy an electric pump setup $550, or buy a new cam $650 and $800 labor to install it.


I agree with roachie, your problem is 100% related to your low lift pump pressure.
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I answered some of the questions within the quote.
 
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