Hey guys,

I have an EFI-PMS and my vent values creep up on their own. This seems to be happening during spirited driving and only on the secondary boost value.

If I stop and start the car (key off, key on), the EFI resets to the programmed values. It's driving me nuts! After 5 minutes of driving I hit fuel cut.

I've checked several times ... vent learn is off.

The software is the latest April 99.

thanks,

James

 

holy moly....i would first have said if your vent values are vent learn on or off. Hum...are you saving the data sets or anything? Is your boost pattern the same at least/

Danny

 

First ... received an e-mail from Wade, the seller of my PMS.

Any of you who have seen his web site know that he's good with this thing. Anyway, he's given me one idea. Maybe the vent learn is showing off, but it isn't really off. This sounds strange, but coming from an IT (computer) background I've seen this sort of thing more than I care to remember.

I've decided to turn vent learn on, across the board. So far, the results are good. I drove to and from work today. Each time boosting several times. The computer raised the secondary boost by one (2 hex) notch. Note that this is on the first program. After another day of driving, I'm going to try the second program. The first is 8/9 ... second is 10/11. Anyway, it's this second one that I know for certain was giving me the trouble.

My intent is to give all of the programs / boost settings a shot. I’d like to narrow things down some. It may take a while though. It's started to rain in Cali. I'm sure that most of you know how easy it is to break the rear wheels loose on a wet street.

So, that said. Here's a better description of what's happening.
Given:
Program 2, boost at 10/11 - pri/sec, vent learn is off, used keypad only (to program).

result:
Vent values for secondary turbo at 11 PSI creep up.
After 5-10 secondary "boosts" I've hit fuel cut at 14PSI.

Weird cause:
If I examine the vent value for 10PSI primary, it's right where I left it. Secondary at 11 however is significantly higher.

Even weirder:
The EPROM isn't being burned with the data. If I shut the ignition off and then turn it back on ... the original vent value returns. If any of you have really dug in to the PMS's operation you know that the up and down on the vent values are slow for a good reason. Each time up or down (1 or 2) is pressed, the new value is written to the units EPROM. Maybe this (my problem) feature could be called vent learn to RAM or vent creep with a short memory.

If anyone has ideas, I'm all ears. In the interim I'm going to play around with vent learn on and off and back on, etc. I may also connect my laptop and use the software to set / reset things.

Wish me luck,

James