Steve Wong chip = DME replacment?
 

Forgive my newbieness regarding the DME system.

My car is exhibiting problems staying running...it is possible that this is due to a faulty DME chip.

Is the Steve Wong chip considered a replacment/upgrade for the standard DME? Thats what his chip is replacing (the one located under the drivers seat) right?

In other words... will his chip solve my cars running problems?

Thanks. Im figuring that if Im gonna need a new DME anyway, that it may be worth trying Steves chip, if applicable.

In short, no. Any problems in the DME need to be fixed before you go to a new chip.

I suspect that most intermittent problems in DMEs are caused by poor solder joints and cracked traces caused by years of vibration. The components themselves are rarely bad.

Tim

I highly doubt that a chip is the source of any such drivability problem. Could be anything from a bad CHT to a relay or electrical connection, or a bad DME itself, or even a fuel pump, but not the chip. The chips are remarkably non-volitile. The board itself has numerous solder points etc that can fail over time. but not the chip itself.

The DME is usually about the last thing in line to go bad after all the other stuff, CHT, fuel issues, speed and ref sensor, AFR, igniton etc.etc.etc...

Can you get more specific with regards to your problem?

BGCarerra... I detailed the problems in another thread. The car just started running funny on a long trip two days ago. I would be driving about 70 and all of sudden the RPMs would shoot up but the MPH stayed the same. One second later, the car would return to normal.

Then the next day while driving around town, Id accelerate and the car would start to rev, and then just temporarily die out (but not stall)....and then a second later would rev up and run fine.

Today I was accelerating onto the expressway and the car died. It wouldnt run again until it cooled down. Then it would start up, run for a short while and die again. I had it trucked back home.....and tonight I just simply replaced the DME relay and now it seems to be running fine. I hope this solved the problem, but you never know.

The reason I suspected DME chip is due to searching old archives in this forum, my cars symptoms mirrored others who had DME problems. Most of those guys spilled liquid on their DMEs and ruined them... i didnt spill any liquids.

Makes sense...another thing to keep an eye on is the air flow meter, as the symptoms also sound like a sticking / worn out flapper door that is sending erratic signals to the DME. The flapper door moving its little potentiometer inside is what is controlling the fuel delivery, and they are very sensitive.

-BG

Something else to look for!

This DME system has a lot of variables that could cause problems bringing the entire system down. Of course, the DME has a great reputation for reliability, but with all of these possibilities (that lead to similar symptoms) it seems to make troubleshooting a bit of a task. :confused:

Sonic - if the problem persists, email me and I will loan you a spare DME to test in your car. It is a pretty straight-forward swap and will tell you right away if that is where your problem is.
Good luck,

Do not forget the cylinder head temp sensor. I swapped out the DME computer and relay thinking (hoping) that these were the problem and it ended up being the sensor.

Check to make sure yours is the upgraded style sensor and if not then change it out anyway.

JoeA

Thomas...that is a very nice offer of you to make. I will email you if the problems persist after I make a couple more minor changes. Thanks very much!

Joeaska... Yes that could be it too. I purchased a new cylinder temp sensor from our host (Pelican) yesterday and am going to install it today. The original is in there and if this doesnt solve the problems then it is at the very least good preventative maintanence.

I don't think it's physically possible for the revs to rise and MPH stay the same...if the revs rise, so does the speed of the wheels unless you have major clutch slippage.

Klaus, you are correct. This problem that I had that day may have been due to my clutch cable, which was getting hung up on the throttle arm near the tranny. I found that the clutch cable had been hitting on the little groove there... its possible that the cable was being hit by the throttle, momentarily disengaging the clutch and as a result giving the appearance of a slipping clutch.

Since then I had the clutch cable adjusted and moved so it is going over the throttle arm and not touching it.

All in a weird week of problems for my car.