I drove my car to school today, and it felt really weak like the ecu+ was pulling timing like crazy. I came home and did a pull with my laptop. When I went wot the A/F's would dip to 11.7:1 and then skyrocket off the chart over 15:1. I haven't changed anything and I have no idea why it is doing this because yesterday the car drove fine. My boost is set at 20psi. No matter what I set the fuel numbers to, it does the same thing. This is worrying me. Thanks.

Dustin

 

Ohh Dear God!!! Someone Help This Man!!!

 

Bad Tank of gas?

 

Where do you have your boost gauge hooked into? If its at the Fuel pressure regulator make sure all the vacum lines are tight.

 

I looked it over quickly, but I will check further when I get home. I will also take the ecu+ out and see if the problem still surfaces with only the bstock computer. It feels like it may be somehting mechanical, but I really don't know. I need to get this figured out this week because I have an appointment next week to get my revolvers installed and my car tuned. I'm sure it is something stupid. The wierd thing is, the boost seems to be exactly the same as it was, and if it was a vacuum line, then I would think the boost would be all screwy. Thanks.

 

My guess would be the vacuum hose came off the fuel pressure regulator, or your fuel pump is on it's last leg. Do you have a fuel pressure gauge? Oh, don't drive it at WOT with an A/F of 15:1 unless you want to rebuild the engine soon.

 

I checked and the hoses are fine. It deffinitely acts like it's the fpr, but I can't find any problems. I just put in a Walbro about 3-4 months ago, so I doubt that is the problem. I'm a little worried. I'll take the ecu+ out and see what happens.

 

my first instinct is/was fuel pump...maybe a clog somewhere...
...injectors?

 

Well, it was the ecu+. I unplugged it and ran the car on just the stock computer and it was 100% fine. Now I need to figure out why the ecu+ got a glitch. Is there any type of reset on the ecu+? I like the ecu+, but I will change if it isn't going to be reliable.

 

subscribed.

 

which version of the ECU+ do you have ??
what are you using to communicate with the ECU+ ??

I had the same problem once .. and traced the problem to a bad serial cable ..

because the ecu+ communicates on the serial ports all the time .. any stray voltage will send weird figures into your ecu+ .. possibly frying it (maybe) especially if you leave the serial cable hooked up to the Ecu+

just check that the fuel adjustment tables are correct and loaded

Lastly ..if you're using the harness .. check there's no lose wires anywhere ..especially from the MAS to the std ECU

 

Thanks. I had the same thing you are taling about happen once as well, but it was easy to fix because all of the values in both tables were all just random numbers. This time, everything looks fine on the computer screen. I'll try to get my old computer that doesn't use a serial adapter back, and see if that fixes the problem.

 

What are you using to read air/fuel ratio?

--Dan
Mach V
FastWRX.com

 

Innovate LM-1. My egt's correspond with the a/f readings because they climb to 900c by 4500 rpm. I am going to email tom a log.

 

A follow-up - it looks like Dustin found the problem. The MAS output frequency clamp had somehow gotten set wrong (way low) so the ECU+ was just following directions and keeping the fueling from exceeding the limit.

Tom