All l28et owners with stock efi READ for your own good.

[Thumper]

This is an FYI not a question. Long story short version is the lower one.

 

For the last two weeks I have had an on/off problem with power when I would hit boost. Sometimes it would do it at 3500rpms and some times at 5500rpms. I hooked up a wideband o2 and it showed the engine going lean. In the neighborhood of 18:1 a/f YIKES Well I tried upping fuel pressure to 60psi at idle. I tried loosening the afm 10 more teeth and nothing helped the top-end. Ran a fuel pressure gauge and ducted taped it to my hood and etc... I have on and off worked on this problem for two weeks as I worked on other things. Then today after 2 hrs of working on this one problem I decided to do a search. OMG NOT A SEARCH!! I didn't do this earlier because I assumed that I would come up with lots of misfire, low fuel pressure, bad sensors, etc... and didn't want to sift through all that junk. Well the 4th post I opened up it was three pages long with about 6 people who have had the same problem. 5 minutes later I drove the car and it runs like a bat out of hell. You ask what was the problem?

 

Long story short if you have miss, lack of power, or very lean condition under boost and you are running the stock efi CHECK YOUR ECU CONNECTIONS. The reason I didn't do this at first is because I had just recently removed the plugs cleaned them and put di-electric grease on them so I assumed they were good. NOPE I unpluged them and plugged them back in and presto all gone. This post is so that a few more people know about this and do not waste so much time and grief over it. Although I might have been the only one on this board who didn't know.

[KTM-EXC]

Thanks for the info, It may come in handy in the future.

[MaTTSuN]

my car was runningbad and good and i checked everything then when i unplugged the ECU and plugged back in and it run better not the best since i need to get the TPS in the right spot after messing with it but befor the #5 and #6cylinder was not working.

[phil280zxt]

Whenever my 81 zxt is running bad, my a/f gauge shows a lean mixture. Reseating the ECU plugs is usually all I have to do to fx the problem. The only problem is that I'm having to go this procedure more often lately. I'm not sure why this is happening. The last time I even lubed the plugs up with dielectric grease, but the problem was back within a few days. I'm beginning to wonder if the plugs are working their way loose over time.....Until I can figure it out, the kick panel stays in the garage!

[Guest bastaad525]

Yep... I have also recently found that even the cleaning and then applying dielectric grease thing will not guarantee that those symptoms will not come back.

 

I find that once every 1-2 mos. or so, the car would start running crappy on boost... I'd usually notice it right away once I hit the go-fast pedal. So I'd just pull over, shut her off, unplug and replug the ECU connectors, and BINGO! it runs as good as... well... as good as it's ever run since I've owned it

 

So... now I just make it a habit to unplug and replug in the ECU every time before I start the car.

 

It kinda sux the dielectric grease isn't a permanent fix, but I still vouch for it, since before I applied the grease, it would start to run crappy every few DAYS, whereas now, it only happens every month or two.

[Guest bastaad525]

hey one thing I'd like to add that fits well with Thumpers topic. For those of us that have tweaked our AFM's for various reasons but are still running stock everything, including stock injectors.

 

I had tightened up my AFM spring about 5 teeth from stock, to lean it out a bit and help with performance and gas mileage, but mostly, to help clean up my idle which has always been kinda rough. But due to some other problems I was getting, just on a whim I decided to put the AFM spring back to the stock setting... this after months of running it at the leaner setting.

 

Well wouldn't you know it, though the idle roughened up a bit, the car overall ran MUCH better. Off boost throttle response was much improved, and it felt much torqueier. I would say it was comparable to advancing timing a few degrees if not more noticeable.

 

So for those of you who have adjusted your AFM's but still have stock injectors, you may want to try putting it back to how it was originally, you may be giving up performance w/o even knowing it.

[spork]

If you do some searching in the archives, either here or the dreaded zcar.com, you'll see that some people have gone as far as opeing up thier ECU case and resoldering the pins to the board. I guess some of these people have found that this will entirely cure thier problem. The connections to the board weren't real great due to time and vibration, and now haven't had any problems since. Just thought I'd throw that out. I've never performed this because I've never had the problems you guys are talking about on my 280zxt.

[zdriffter]

Hey Whats Up Guys....well I Have A L28et On My 240z And Ive Messed Around With The Afm. For Messing With It So Many Times Ive Lost Where It Should Be Set At. How Do I Find Out Where The Stock Set Is At ? And One More Question.... Does It Really Matter How My Afm Sits On My Car? Should The Flap Be Vertical Or Horizantol? Thanks Guys

[Garrett76Zt]

yep broken ringlands in cyl #1 taught me that lesson! SDS came right away with the next motor.