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ECMlink bad idle, car stalling, trying to narrow down problems

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TimF

10+ Year Contributor
823
5
Mar 14, 2011
Aurora, Illinois
Ok so I have a 91 tsi awd project car that I rebuilt the motor in and am now trying to get it derivable. The issues I am having are the car will start turn key no problem, idle decent then the idle just goes to shit and is everywhere, ranging from 400rpm and 1300rpm. (kind of in a surging motion but sometimes drops lower/ goes higher than the time before) If I give it gas the car will rev up and and hold the rpm at the given amount of throttle opened. If i let it sit with no gas it just stalls, but always turns right back over. issue two is I can not rev past 3k with out the car bogging out, and the turbo will not build boost ( will go to 0 on the boost gauge but never actually builds psi) I am sure this may be related with issue one. When the car is rolling and my foot on the gas it drives fine, but still wont go past 3k, and stalls when I go into neutral unless I keep my foot on the gas
Now here is the mod list of the car
6 bolt block, rebuilt with stock crank, 6 bolts rods and evo pistons, all arp hardware and bse
6 bolt head with FP springs and retainers, 272 cams skunk2 adj cam gears, 3g lifters
hx35 with BEP housing, evo3 cast manifold with tial 38mm wastegate off manifold to dump, SS o2 housing to 3in megan DP (pipe is open no cat back on car yet)
Punishment racing IC with piping and real GReddy BOV and 1g nt TB
FIC 1000cc injectors, aeromtive fpr, russel SS fuel filter and walbro 255 pump with rewire, fuel pressure set correctly
ECMlink v3 full on speed density (4bar omni sensor and GM IAT with plug in harness) boost gauge, wideband, oil pressure (reading flow to turbo) and coolant temp gauges
New NGK plugs, wires and coil pack

Here is what I have done and determined I need to resolve
Boost leak test, TB is leaking from shaft seals, new seals will be installed along with FIAV bypass and new BISS o ring (also leaking)
Injector is leaking air so new bottom seals will be installed, I tightened all couplers that had slight leaks BOV is not leaking at all. I still dont feel that the small leaks would cause that much issue but I may be wrong.
ECMlink settings are set for omni and gm sensor, and injectors. although my intake temp sensor always reads 77* regardless of current temp (faulty sensor?) all other senors are working
wastegate is not leaking exhaust
turbo seems healthy, no shaft play, no signs of blown seals (no oil in intake and no burnt oil in exhaust) wheel spins fine and you can here it spooling at idle and start to spool up when you give it gas.
checked timing with gun and link both read correctly

I am wondering what other things to look for(both mechanically and on link) to try and get my car running right for the time being I just want to be able to casually drive and break the motor in and then I will have it professionally tuned. thanks in advanced
 
I will double check that but it was rebuilt not to long ago. I also recently had it in another 1g and it worked perfectly fine in that one and read everything properly.
 
Sorry I was finishing up a paint job on my brothers car checked
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my ecu it looks fine to me, and it was rebuilt (had one of those stickers that says rebuilt by xxx) I fixed the boost leaks but idle is still crappy (just does not stall itself), I still cant build boost, I took it for a 3 block drive to my friends house and every time I would try to accelerate it would hesitate, run lean (drop to about 17 on afr gauge) then pick up. It does the same thing if I give it gas, it hesitates then will rev up.

I can get a log probably tuesday
 

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I have a log from going around the block how would I attach it
 
think I got it
 

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I have no idea
 
Go get another log.

Start the recording before you start the engine and after a second or so, run the throttle through it's full range, then you can crank the engine.

Add ISC position and fuel trims to the variables logged.

Did you intend to pull timing like you have?

If you still have an FPS installed, enable it.
 
I really am not sure on how to use link I read through the starter process to get it going. And no I had no intention of pulling timing. And no fps, I just have a aeromotive fpr. Ill try and get another log tomorrow before work
 
Is there a reason you wouldnt use the "Simulate Idle switch from TPS" function?

It's a band-aid. I was intended for people with replacement TBs that don't have a switch.
In this case it wouldn't help because the TPS doesn't seem to be working either.
 
here is from today didn't drive it I was running short on time
 

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It's a band-aid. I was intended for people with replacement TBs that don't have a switch.
In this case it wouldn't help because the TPS doesn't seem to be working either.

I disagree with it being a band aid, it's eliminating a point of failure really. Also it is usable as an input for dual map functionality if not used as the idle switch.
 
I disagree with it being a band aid, it's eliminating a point of failure really.

Then we can agree to disagree. I believe in fixing things that are broken rather than covering them up.

here is from today didn't drive it I was running short on time
No problem Tim, what does the log tell you when you look at it?
 
Steve I know you wanted him to use his brain to attempt figuring it out but since I'm having idling issues of my own, and I'm new at link let me take a shot.

* IdleSw operation isn't working I'd at least temporarily use idle simulation but fix actual idle switch. (Then verify FrontO2 cycling in
* Looks like injector deadtime may need some adjustment to compensate for CombinedFT (off by about 10%)

MAF and AirflowPerRev look off but not sure how they're supposed to look like on speed density.
 
I didn't have CombinedFT displayed but you can see that at about 87F coolant temp the ECU tried to go into closed loop and failed. It wasn't until he rev'ed the engine that the O2 started switching but at idle the required adjustment is out of range to cause the sensor to switch. The ECU tried to pull 10% and that wasn't enough.

The IPS problem is either a bad TB ground, broken wire from the ECU, bad switch, or mismatch between ECU version and car model year. Simulating it is fine for debugging but as noted I'd just figure it out and fix it.
 
So should I simulate IPS and front 02 and see how it runs off that?
 
Simulate IPS, yes why would you simulate FrontO2 unless you know it's bad? When you get idle switch operation working ... put IdleSW on displayed values and it should show 1 instead of 0 when TPS gets down to 0. It goes into closed loop at that point so you should see your FrontO2 Cycle from 0.8V to 0.2 about, repeat, and make adjustments to CombinedFT. Once you have that working you can finish dialing in the injector deadtime.

I don't think you've watched all the ECMlink demo videos here:
http://www.ecmtuning.com/demos.php
 
Tim, what I was looking for from you, was to notice in the new log that the TPS is working and that the IPS wasn't. So you need to simulate it or fix it before you can move forward.

I was also questioning your timing settings to make sure that you started your tuning from a factory reset and could explain why you changed any settings. If you haven't now would be the time to do so.

What is your base fuel pressure set at?
 
Fuel pressure is set at stock 1g manual pressure. And my idle switch is working I just had the throttle cable to tight it is going 1 to 0 now
 
The first log is from driving with out the IPS simulated 2nd log is from a short drive with IPS simulated it seemed to run a lot better with IPS simulated.

It seems my idle switches does not work if the car is running but does if my car is off.

if i give the car gas it bogs and studders and my wideband read it runs really lean (18) then it pics up normally and runs rich in the upper rpm range (which im sure I can adjust fuel setting for that)
 

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