7747 on a Ford 400 - still not getting a backfire issue sorted

**1project2many** · 01-22-2016

Thank you! But first things first - I gotta find a way to ship an E4OD to Germany without getting bankrupted by shipping cost. ;)

I work with a girl who has family in Germany.
I can find E4OD transmissions.
I am interested in parts used on certain Opel vehicles that have no equivalent here in the US.
At some point it might be beneficial to work together.

**Dr_Grip** · 01-22-2016

Originally Posted by 1project2many

I work with a girl who has family in Germany.
I can find E4OD transmissions.
I am interested in parts used on certain Opel vehicles that have no equivalent here in the US.
At some point it might be beneficial to work together.

As the owner of a late-70s Opel I an pretty good at acquiring Opel parts. Shoot me a PM what you need and I'll look around :)

**Dr_Grip** · 03-17-2016

Finally getting there! After lots of dabbling with the AE settings, she's running mostly great, with an AFR under AE between 12:1 and 13:1 - but the WB o2 tells me that starting from a standstill and accelerating at low rpm, I hit 10:1. I can feel her hesitating a bit, even.

As I am a bit lost as to how MAP AE and TPS AE work together, I can't really tune that behavior out. A log and the bin's attached, and I am glad if someone can help me out!

**Dr_Grip** · 03-29-2016

Originally Posted by Dr_Grip

Finally getting there! After lots of dabbling with the AE settings, she's running mostly great, with an AFR under AE between 12:1 and 13:1 - but the WB o2 tells me that starting from a standstill and accelerating at low rpm, I hit 10:1. I can feel her hesitating a bit, even.

As I am a bit lost as to how MAP AE and TPS AE work together, I can't really tune that behavior out. A log and the bin's attached, and I am glad if someone can help me out!

Gotta bump this. Still at a loss. Any ideas?

**sturgillbd** · 03-29-2016

Too much AE will cause a bog/hesitation also. There are several threads here on the forum with info on tuning AE.

http://www.gearhead-efi.com/Fuel-Inj...1647-Tuning-0D

Here is one from another forum that describes tps and map ae

http://www.ifsja.org/forums/vb/showthread.php?t=149344

HTH
Brian

**Dr_Grip** · 03-29-2016

Thank you for the input! So basically, I have to check TPS AE in the affected TPS % range. Will do and report back (my girl told me to take the next weekend off from wrenching, so it'll take some time, but I will report back).

**Dr_Grip** · 04-10-2016

Reporting back - getting there, even if tuning the TPS AE is a real PITA and involves more trial and error than I generally like. Thank you all for your input!

**400_Fordman** · 01-26-2017

So glad to see someone else had the same idea as I did to convert a Ford 400 to gm efi! I just started my conversion, had no idea anyone else had tried until I googled for ford 400 knock sensor and your posts popped up. I'm a bit of a greenhorn when it comes to tuning but if i make any progress with mine, ill let you know. Perhaps we can work on it together. Im planning on using ebl flash. The only downside is my 400 is a 79, so it might tune different. Im still assembling mine at the moment, planning to start tuning in a month or so. I think your build is awesome BTW. Its really cool you took a full size car and went racing! :D

**Dr_Grip** · 01-29-2017

Originally Posted by 400_Fordman

So glad to see someone else had the same idea as I did to convert a Ford 400 to gm efi! I just started my conversion, had no idea anyone else had tried until I googled for ford 400 knock sensor and your posts popped up. I'm a bit of a greenhorn when it comes to tuning but if i make any progress with mine, ill let you know. Perhaps we can work on it together. Im planning on using ebl flash. The only downside is my 400 is a 79, so it might tune different. Im still assembling mine at the moment, planning to start tuning in a month or so. I think your build is awesome BTW. Its really cool you took a full size car and went racing! :D

Always glad to help and let's work together wherever it helps! The backfire issue is mostly MAP AE vs. TPS AE, so tedious, tedious woring with the wideband o2 sensor to tune it out without going too rich. Additionally, the stainless steel cam gear on my $49 aftermarket dizzy ate up my stock camshaft, so I had to do some rebuilding work anyways and decided to stick a set of 1971-style flat top pistons into the engine to boost compression to 9.sometihng:1. I also decided to go for an Edelbrock cam instead of the stock one while I am at it. The rebuild hopefully will be done during Febrary. Then I'll be back at square one with my fueling tables anyways, so I'll let you know how it goes!