I'm posting this because I've just recently started having this problem. The post describing my symptoms can be found HERE.

Here are several other threads where this problem is discussed:

More MAF problems - PE TT

Bad news for the big boosters...!

So, the purpose of this poll is to see if your car has gone into limp mode. If so, please feel free to post more information below.

 

The Greddy eManage clamps voltage at 5.0V, so limp mode is a non-issue. With the PE, there is the potential for limp mode, depending on when max airflow is reached.

A solution would be to install a simply electronic CLAMP on the MAF signal so that it would clamp the voltage at 5.0V, or slightly under...like 4.97V

 

How does clamping at 5.0v solve the problem? I thought that what caused the problem was the ECU reading a MAF voltage of 5.0v prior to 4xxx rpms.

Are you saying that the Greddy clamps at just barely below 5v? Also, I'm assuming that the Greddy allows the value to be less than 5 volts but never greater than or equal to 5v. Is that correct?

--Steve

 

That's correct. The eManage makes it so that the ECU never sees more than 5.0V. It actually never lets it get exactly to 5.0V. Mine peaks at 4.97V, which keeps the ECU from freaking out.

 

zimbo:


I had a chance to talk to danny after I pm you. He said the zenor diode method could work but won't garrentee on what the ecu would do. If you want to try it here is some info on this. for me like I said I will be loading the emanage once i finish my block.




http://minimopar.knizefamily.net/perf/beyondwcb.html


http://home.earthlink.net/~micfly/zener.htm

 

I'm planning on purchasing eManage anyway. I'm going to need the injector scaling soon enough and it's nice to have a bit of control over A/F (the TS PE TT reflash is close but not perfect in my case). Sounds like I might as well get this immediately.

Dumb hypothetical question: say I like the TS reflash all except I want a little bit of extra fuel at 5500 rpms (but it's not needed at 6000rpms) for example. Can I do this with eManage if the MAF voltage is clamped at 5volts? I thought the fuel maps were MAF voltage based--or is there an RPM component as well?

--Steve

 

maf but also rpm and throttle position. so yes you can fix 5500 and not 6000rpm.

 

correct..but actually, there is no need for TPS, and Greddy doesnt even wire it up as standard. It is possible to wire it up, but it's not needed. MAF is a surrogate for TPS (they are essential "engine load"). So the fuel table is a 16X16 table with RPM on the top, and voltage on the side...or the x and y axis for your mathematical nerds.

You can add fuel anywhere or everywhere...it's up to you.

 

It's probably a given, but you'll need the injector harness to add fuel once you've exceeded the MAF capacity.

 

Ok, I ordered the eManage and various harnesses

I'm assuming that if I don't want to change the fuel level at a particular spot on the 16x16 grid, I simply leave it at zero, right?

Also, I'm assuming that you choose to configure either a MAF-voltage-based map or a boost-based map but not both, right?

--Steve

 

You are correct!

Make sure to get the injector harness, and the RPM adaptor...you will need both. If you plan on retarding timing further than what is programmed into your TS reflash, you might as well get the $29 ignition harness as well. And dont forget those diodes before you wire it up.