hci installed, need tuning help!

[montyd]

got my hci installed. am runing edelbrock performer heads and a crane came(.512 lift) and a cobra intake. have 24 lb injectors and maf, 65 mm throttle body. got it all installed and it runs but has no power and isnt smooth after 3000. and as soon as you let off it back fires. and sometimes back fires as soon as you hit the throttle. any ideas? the timing is at 13 degrees. i cant figre this thing out the valves aren't hanging open checked all of them. there all in spec. any help would be great! thanks

 

[ttop88]

Whats the fuel pressure at? I would start at 35#. Check your plugs to see how they look.

 

[Dark_5.0]

Firing order or timing issues

Set the fuel pressure at 38psi with vacuum line off and forget about it.

 

[montyd]

pulled a couple plugs, there black, so i have to much fuel. dont know the pressure, will get a gauge tomorow and check it out. i didnt change any of the fuel system other than the injectors. still has the stock regulator and all.

 

[jhonda]

pulled a couple plugs, there black, so i have to much fuel. dont know the pressure, will get a gauge tomorow and check it out. i didnt change any of the fuel system other than the injectors. still has the stock regulator and all.

Is your Maf sensor calibrated to the new injectors if not thats probley your problem

 

[back2fox]

Mine did the same thing after my h/c/i.

I had my distributor out of wack. If you have another mustang handy. Look at their position of the dizzy and try to get it as close as possible. Then set the timing.

And of course the maf has to be calibrated for 24lb injectors.

 

[montyd]

the maf is calibrated to 24lb came out of a running set up. i have been messeing with the dist. and timing for a couple days havent really made a whole lot of progress. will keep trying tho

 

[ShortThrow50]

TRy retapping the distributor first dude. simplist things first. Put your engine at top dead center (air blowing out of 1st cylinder with spark plug removed). Pull your distributor cap off and check to make sure your rotor is pointing to the No. 1 cylinder electrode. If it is not on top or JUST a hair a out to hit it, then you will need to undo the bolt and pull up the distributor and rotate the rotor so it will be there and push the distributor back down. Sounds to me that this is the problem. It DOES NOT matter if you have the NO.! pointing at 12 oclock. I havemine at 11 oclock for better adjustabililty clearance. At 12, I always had probles turning the distributor becaue it would hit something.

 

[irish]

How did you check the pushrod length?

Get a FPR.

Check koeo and koer codes.

Matt

 

[mustangfan1990]

does it have stock rocker arms?

 

[montyd]

did some diggin on it today and got no where. finally pulled all the cam paperowrk out and looked it over really close and found that it was for a non ho motor so the firing order was off four cylinders. flipped them around and ran like a top. rookie mistake i guess. took it out and pulled four cars on my buddies ls2 gto no problem. thanks for all the help guys.

 

[dcurtis]

They make a cam for 5.0's that take a diferant firing order? I thought they were all the same since the injectors are still going to go off in the same order?

 

[mustangfan1990]

They make a cam for 5.0's that take a different firing order? I thought they were all the same since the injectors are still going to go off in the same order?

if it is a non HO 5.0 then the firing order is different

 

[PJC Racing]

Your not trying to use the roller lifters on that cam are you? I know stupid question, but you never know.

 

[vristang]

did some diggin on it today and got no where. finally pulled all the cam paperowrk out and looked it over really close and found that it was for a non ho motor so the firing order was off four cylinders. flipped them around and ran like a top. rookie mistake i guess. took it out and pulled four cars on my buddies ls2 gto no problem. thanks for all the help guys.

There can still be issues with this setup....
http://www.fordfuelinjection.com/?p=92

good luck,

 

[vristang]

They make a cam for 5.0's that take a diferant firing order? I thought they were all the same since the injectors are still going to go off in the same order?

Bingo!

The HO ecu fires the injectors in a specific order...

Using a cam that fires on the 'other' firing order can cause issues when the Adaptive starts to make corrections.

If you can keep the Adaptive near zero (KAMRF/LTFT = 1.0), then you may never notice it.
But if anything causes the Adaptive to make changes bank to bank, then the ecu is going to throw fits....

jason

 

[montyd]

been driving it for two days runs like a champ, no issues at all so hopefully it will be ok in the end. the cam is a roller cam not a tappet cam i dont know why the order is different but it all works fine and is a blast to drive.