no smoke, low power

9cummins4

9cummins4

average joe
Joined
Oct 23, 2009
Messages
48
My buddy's has a 94 auto that was bone stock. We put cold air and 5" exhaust and gauges. We took off the plate and ground a #10 plate and did the afc mods and put a boost elbow in it. I checked the fuel pressure and at idle we had 19 psi and at 2500 we had 28 psi so I know it's good. The problem is we can't get it to throw any smoke no matter where we put the plate or where we set the star wheel. I checked the gov arm and it's where it needs to be. When he hits the pedal it takes off and stays around 2400 rpm and goes threw the gears but it is not a big difference from before. No adjustment that we make on the plate or star wheel seems to do much. any ideas?
 
Fuel pressure is fine.

Maybe the afc line has a boost leak so its only getting pre-boost fuel.

You could take out the afc arm to check real quick.

Its a 160 pump with a auto so the difference won't be real drastic.

what about snaping the go pedal in neutral?
 
I'm placing my money on leaking/crimped AFC signal line, or a boost leak. When I swapped injectors in my 12v, I forgot to tighten the clamp on the airhorn boot. No smoke, and no go. Only 5 psi. Tightened it up, 43 psi and a lot more go.
 
We went thru the fuel system and cleaned the pre screen filter. It has a new lift pump and filter on it and I checked it after it all was said and done. Where does the afc get it pressure from and is it common to leak some where besides on the afc housing
 
When we hit in neutral there is very small haze but it clears fast. Being this is a 160 truck and it's a auto is it so limited that a plate and afc won't do much for it
 
9cummins4 said:
We went thru the fuel system and cleaned the pre screen filter. It has a new lift pump and filter on it and I checked it after it all was said and done. Where does the afc get it pressure from and is it common to leak some where besides on the afc housing
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The afc line is from the intake manifold to the backside of the afc housing.

Make sure that the fuel shutoff arm is coming up all the way. Easy way to check that is to take off the fuel shutoff solenoid and ziptie the arm up, you will have to cu the ziptie to shut of the pickup though.
 
a 160 pump should have a noticable difference in power with a fuel plate. i know when i put mine in it was like night and day. it sounds like you need a governor spring kit too so you can get it to fuel harder into the higher RPMs. i think thats why you are just hanging around 2400RPM. it sounds like you may have a leak in the line going to the AFC as well. you could remove the AFC and blow shop air (regulated down to 30-40 psi) into the tube from the intake end and see if the arm is moving inside the housing. this would show you if you have a leak in the hose or maybe a hole in the diaphragm... hope you get it fixed
 
estrada5.9 said:
The afc line is from the intake manifold to the backside of the afc housing.

Make sure that the fuel shutoff arm is coming up all the way. Easy way to check that is to take off the fuel shutoff solenoid and ziptie the arm up, you will have to cu the ziptie to shut of the pickup though.
Click to expand...

No need to zip tie the arm up, it is always in the run position unless held down.
 
With the stock solenoid you have to hold the shutoff up it is held normally closed so that the pump doesnt loose prime when the lift pump stops at shutdown.
 
12valvetater said:
With the stock solenoid you have to hold the shutoff up it is held normally closed so that the pump doesnt loose prime when the lift pump stops at shutdown.
Click to expand...

The shut off lever has nothing to do with the fuel system keeping prime. It just pulls the rack all the way back.

I drove my 24v for 4 months with no shut off solenoid because I didn't have the time to put in the wiring harness. Put on probably 12k km that way. Had to pop the hood to shut it off. Just jump in to start and leave. Lever is normally up, and the solenoid is normally down. Solenoid spring pressure is to hold the lever down.
 
when i put ddp2's in with a boost elbow, i got slight smoke with a no boost launch, with the stock plate full forward i got a good amount of smoke from same launch. tuned afc now it spools faster and i clicked the stock gov springs 2 clicks which got me to defuel at 2900 instead of 25ish. smoke increased abit as well. i can break the tires loose from a 30mph roll on now. when i first got my truck it was a complete dog, i could ride my bike faster, it hadnt occured to me to check the waste gate, it was completely non funtional maxin at 10 psi.
 
That's one I didn't think of, if it's stuck can you make it work again
 
i ment the WG actuator sry. but mine could be wiggled from side to side and back and forth...so when i hit a bump the thing would open and close etc..if its shot its shot. i got a new oem one from crosspoint for a very good price.
 
We have the waste gate blocked off so the wg actuator shouldn't matter right or is it better with a boost elbow
 
as long as its not leaking and the afc is gettin its boost reference the afc will move allowing more fuel. from what i read it sounds like their is a leak in somthing.
 
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