Timing problem with a modified 3FE need help

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Aug 23, 2018
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new richmond wi
ok this is my problem im having with my truck it has a rebuilt engine not stock it been board 3.740 with Ross racing pistons head has been match ported headers and the cam was reground
here are the cam spec. master intake 689f exhaust 689f cam lift 260 lob separation 108 . So the problem im having is getting in proper time i have Alldata and i am doing everything to set the timing it runs with out a problem but it has no power i hold the brake and it just pops and misfires so i think the factory timing wont work for the cam in it i put a vac gauge on it and it is reading late timing i lost
 
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Jan 6, 2012
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ok this is my problem im having with my truck it has a rebuilt engine not stock it been board 3.740 with Ross racing pistons head has been match ported headers and the cam was reground
here are the cam spec. master intake 689f exhaust 689f cam lift 260 lob separation 108 . So the problem im having is getting in proper time i have Alldata and i am doing everything to set the timing it runs with out a problem but it has no power i hold the brake and it just pops and misfires so i think the factory timing wont work for the cam in it i put a vac gauge on it and it is reading late timing i lost
So are you getting spark? With a custom cam your going to need a custom timing map in the ecu to get full potential our of a non stock camshaft. So your talking a aftermarket ecu or a hacked and reprogrammed ecu. But first verify your distributor was stabbed correctly and is not 180 off. Make sure all the wiring is correct.
 
Joined
Aug 23, 2018
Messages
4
Location
new richmond wi
So are you getting spark? With a custom cam your going to need a custom timing map in the ecu to get full potential our of a non stock camshaft. So your talking a aftermarket ecu or a hacked and reprogrammed ecu. But first verify your distributor was stabbed correctly and is not 180 off. Make sure all the wiring is correct.
ok the distributor is not 180 off . I spoke with the guy who ground the cam it is possible that the machine shop put the cam in wrong it like the cam is one tooth off if you look at the distributor the rotor is not pointing where it should be. this is the OE position on the rotor on my rotor the at the bottom part of the drilled hole as a reference point. ok this right from Alldata the Distributor on these engines only go in one way it bot like a Chey or a Ford on a Toyota it ether its on or off

rotor position.png


TDC.png


drill mark.png


oil pump shaft alinment.png
 
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Sep 13, 2021
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CT
ok the distributor is not 180 off . I spoke with the guy who ground the cam it is possible that the machine shop put the cam in wrong it like the cam is one tooth off if you look at the distributor the rotor is not pointing where it should be. this is the OE position on the rotor on my rotor the at the bottom part of the drilled hole as a reference point. ok this right from Alldata the Distributor on these engines only go in one way it bot like a Chey or a Ford on a Toyota it ether its on or off

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Any updates?

I just purchased an extra 3FE to have rebuilt and was looking at doing the same thing as you. Plus I am adding a turbo with Water to air cooler, keeping it around 10-14 (1bar) psi.

I personally feel, The stock ECU is super touchy. My 92 FJ80 can run awesome; however, the moment I turn it off, walk into a store and come out… it runs completely different like a bag of junk, it will be having random misfires and all kinds of lameness…

That is why I am going to run a Megasquirt or MicroSquirt - I would love to make a an adapter plate (I have a Haas VF4SS CNC) and run a GM throttle body and use an FAST EFI or a Holley Terminator, and let the system do the tuning, and I would only make tiny corrections. I need to plan this out more.

I really would like to know how you are making out with this!!!

Have you thought about asking @jonheld about your ECU problem? He is the ECU 3FE master around IH8MUD. Maybe he can give you his take on it.

Wish you luck bro!
 
Joined
Aug 23, 2018
Messages
4
Location
new richmond wi
Any updates?

I just purchased an extra 3FE to have rebuilt and was looking at doing the same thing as you. Plus I am adding a turbo with Water to air cooler, keeping it around 10-14 (1bar) psi.

I personally feel, The stock ECU is super touchy. My 92 FJ80 can run awesome; however, the moment I turn it off, walk into a store and come out… it runs completely different like a bag of junk, it will be having random misfires and all kinds of lameness…

That is why I am going to run a Megasquirt or MicroSquirt - I would love to make a an adapter plate (I have a Haas VF4SS CNC) and run a GM throttle body and use an FAST EFI or a Holley Terminator, and let the system do the tuning, and I would only make tiny corrections. I need to plan this out more.

I really would like to know how you are making out with this!!!

Have you thought about asking @jonheld about your ECU problem? He is the ECU 3FE master around IH8MUD. Maybe he can give you his take on it.

Wish you luck bro!
we i finely think i got it . it took some time but i timed it had to modify the side cover and do some modifying to the distributor but its in time for now be for when i power brake to check the power ban it now revs to almost 2000 rpm were before i only got 1500 and it would not push through the brakes i spoke to the people who ground the cam it is a higher rpm cam then i like power starts a 2200 rpm i told my machine shot i wanted 500-4500 rpm well i did not get it so have to do some modes like change out the gears maybe 488
 
Joined
Sep 13, 2021
Messages
7
Location
CT
we i finely think i got it . it took some time but i timed it had to modify the side cover and do some modifying to the distributor but its in time for now be for when i power brake to check the power ban it now revs to almost 2000 rpm were before i only got 1500 and it would not push through the brakes i spoke to the people who ground the cam it is a higher rpm cam then i like power starts a 2200 rpm i told my machine shot i wanted 500-4500 rpm well i did not get it so have to do some modes like change out the gears maybe 488
Glad to hear you are making progress!

Have you tried using a stock cam, and see if you get the same problem?

I will send you mine as soon as I pull it out of my extra 3fe that I am rebuilding, if you want.

Side question, did you have to use longer pushrods since they ground your cam?

You shouldn’t have to modify your side cover, or the distributor, unless you reallllly changed your cam profile a lot. Still sounds like it is something else.I hate these 3FE ECU’s, I bet they are super robust and are good for longevity and saving the engine in weird circumstances… but dang. You can’t mod/hack/chip/reprogram them at all… super annoying.

Another thing to check that I did that helped me. Move the AFM wheel 2 clicks clockwise and see if that helps your power out at all. It made the biggest change out of anything I have ever done for my 3FE - I mean huge. The engine completely changed, the idle smoothed out, the shifting kickdown was better, fuel consumption… I was even able to bench 315 x 5 times… joking. But seriously, the 2 clicks made so much of a difference.

I have no clue why it can make such a dramatic impact. And I am really confused as to how it made my kickdown better!
 

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