Atomic EFI and dealing with MSD tech support

[Landyacht]

I have just recently installed an Atomic EFI fuel injection system in my 73 Newport. The power gains I got from switching over to this system are outstanding but like any upgrade there is a lot trouble shooting and working out bugs that goes along with it. My problem is with MSDs tech support. When you call these guys for advice they talk down to you in a condescending manner and the advice they give you is pretty much useless. It almost seems like they're reading a script off of a cue card or computer screen and have no actual detailed knowledge of their own product. I joined their support forum and posted some of the issues I was dealing with and the response I got from them was "Did you install the system correctly? Is your fuel regulator installed right? Where is your fuel pump mounted? Did you install the fuel filters correctly?" Pretty much the basic stuff that you can find in the owners manual. When I responded to them that I had made sure that everything was installed correctly and that I had gone over everything several times over just to make double sure they just pretty much ignored me from that point and haven't replied to my thread. I am wondering if anyone here has any knowledge of this system and can possibly throw out some advice.

 

[CanCritter]

big mistake alota folks make is putting fuel reg in front of tbi ect.....should be after tbi on return line to tank.....your problem is??

welcome to the site enjoy

 

[Landyacht]

MSD told me the exact same thing. The fuel regulator is installed in the right place. The instruction manual even shows two illustrations each showing the correct and incorrect way of plumbing the fuel system. My problem is that I am getting an error code that tells me that my injectors are being over worked. It comes up as "INJ DC " code or excessive injector duty cycle. the owners manual explains to correct the problem by increasing the fuel pressure and I have tried that with not much luck. The code only pops up only under wide open throttle. If I erase the code it will not come back as long as I don't get on the throttle too hard.

 

[Yatzee]

Depending on the size and demands of your engine you may be on the cusp of the limitations of this particular system. I calculated that I would need 80 p.s.i. fuel pressure to satisfy the demands of my 513 stroker because of the injector size of the TBI. That's a sh*t load of pressure to keep them in their duty cycle. Solution: FAST TBI with larger injectors and a good in-tank pump to deliver both pressure and flow characteristics at either 12 volts or 13.5. This is one case where "bigger is better", You can only imagine how fuel line size and length affects pressure and flow as the line itself inhibits a restriction. What you start out with at the tank is definitely different from what you end up with at the other end of the car. That's why pump pressures are rated at the outlet end of the pump only. I use 3/8 line to limit flow restrictions so when the TBI asks for fuel, it's there by the bucket full. Perhaps you should revisit the fuel pump and it's capabilities.

 

[68plymouth383]

Welcome to the program! !

 

[Landyacht]

Depending on the size and demands of your engine you may be on the cusp of the limitations of this particular system. I calculated that I would need 80 p.s.i. fuel pressure to satisfy the demands of my 513 stroker because of the injector size of the TBI. That's a sh*t load of pressure to keep them in their duty cycle. Solution: FAST TBI with larger injectors and a good in-tank pump to deliver both pressure and flow characteristics at either 12 volts or 13.5. This is one case where "bigger is better", You can only imagine how fuel line size and length affects pressure and flow as the line itself inhibits a restriction. What you start out with at the tank is definitely different from what you end up with at the other end of the car. That's why pump pressures are rated at the outlet end of the pump only. I use 3/8 line to limit flow restrictions so when the TBI asks for fuel, it's there by the bucket full. Perhaps you should revisit the fuel pump and it's capabilities.

I'm running this system on a 470 stroker with basicly a performer rpm package( heads not ported) and a Comp 284xe cam with 240 duration @.050 and .507 lift on the intake TTI headers with1 7/8 primarys and three inch exhaust. The engine has never been dyno tested but I am guessing the horsepower to be somewhere around 500 maybe slightly less. I did have the regulator adjusted up to 75 psi never quite went to the 80 mark. Msd claims thier system will support up to 525 hp with the supplied pump and 650 hp with a pump upgrade. I am currently using the pump that came with the kit. It might be possible that the pump doesn't actually support what MSD claims. Another thing I was pondering was the possibility of the fuel in my tank sloshing around under heavy acceleration causing the fuel system to take in air.

 

[moper]

Sounds like the injectors are too small. Rating by horsepower is like rating a cam by lift. There are too many variables to simply assume it will work when you're that close to the system's limit. You need to calculate what it needs for fuel, then size the injector for the pressure you have. I've never run anything but FAST stuff, and not in a while. But offhand if the duty cycle is too high, and the presure is within 15% of the max pressure (my own safety margin), the injectors are too small.

 

[BJS racing]

I can tell you that the tech guys do not have it easy man. I do tech support at Painless wiring and when you deal with as many calls as we do it gets a little hard to make it through the day much less the week sometimes. It's not a script but you also need to realize that we get so many of the same (basically the same) calls from different people and you kind of build your own system as to how to deal with a majority of them. On your issue I would agree with moper that you are pushing the system to it's limits and there is not enough flow in that pump to support your engine and it is having to keep the injectors open for too long which is triggering the code it is throwing. I would upgrade the pump on it and that would likely take care of your problem. I don't think you have enough fuel getting to the injectors to support high rpm/load that your engine is demanding. And those numbers that they give are guide line numbers. A 500 hp small block actually doesn't use as much fuel most of the time as a 500 hp big block will.

 

[Landyacht]

Thanks for the advice. You were all extremely helpful.

 

[mpgmike]

I'm curious as to how the ECU monitors for the code. I assume you have an oxygen sensor. Is it a wide band? Although I'm not familiar with that particular brand, are you able to do data logging? If so, where are your AFRs going when at WOT? It may be a software issue.

Mike

 

[Landyacht]

I'm curious as to how the ECU monitors for the code. I assume you have an oxygen sensor. Is it a wide band? Although I'm not familiar with that particular brand, are you able to do data logging? If so, where are your AFRs going when at WOT? It may be a software issue.

Mike

My best guess is it monitors it by a combination of fuel pump pressure O2 sensor reading and the injector duty cycle reading. All three can be monitored in the live data section on the handheld device. It has a wide band O2 sensor . I don't believe its capable of data logging. MSD does offer software updates that you can download onto a memory card. I haven't tried to monitor the live data while driving but I do notice a slight hesitation at WOT.

 

[70bigblockdodge]

I have no experience with any efi but I do read as much technical stuff as I can get my hands on. I would have to say that your fuel system is getting pushed beyond its limits and if the pressure is not falling off at WOT as in a carbureted car not enough volume, it has to be in your injectors. One bright spot is that maybe their rating is correct and you are beating that number.s_dancing2:

 

[Landyacht]

I have no experience with any efi but I do read as much technical stuff as I can get my hands on. I would have to say that your fuel system is getting pushed beyond its limits and if the pressure is not falling off at WOT as in a carbureted car not enough volume, it has to be in your injectors. One bright spot is that maybe their rating is correct and you are beating that number.s_dancing2:

I would like to think that, but from what I am told Performer RPM heads on a big block mopar are only good for around 500 hp. That would be straight out of the box with no porting work. Right now as it stands I will probably be tearing my motor down to fix some other issues. I might perform a few mods on it as well such as porting bigger cam ect so I will probably get a fuel pump upgrade also.

 

[70bigblockdodge]

Have those big ends resized and get the crank turned so you know the journals are round and uniform across the surface.

 

[Landyacht]

Have those big ends resized and get the crank turned so you know the journals are round and uniform across the surface.

Now I need to find a good honest machine shop to do the work. The place I took my block to get the machine work done were pretty decent but I'm not sure if they do crank work. I know they farm out all their crank balancing. The name of the place was Chucks Engine Exchange.