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HELP! Bad gas? (logs and now VIDEO)

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kmetiuk

10+ Year Contributor
521
125
Mar 10, 2010
Edmonton, AB_Canada
I am stumped here. One night fine, next morning not. Zero changes to the car. It did drop from +8C to -10C overnight tho so I'm feeling like the temp change broke something or somethings not happy now.

Anyways, I went out to start my car and after warming up it started to very slowly go lean. The night before I was driving it and my AFR's are all bang on across the whole range. Idle-crusie-wot. All fine and bang on target.

After it was warmed it up and while I was looking at my log from the night before; the the car starts going lean.... very very slowly. Over about 2-5 minutes it went from combinedFT of ~0% to pegging it at +17-20% at which it stopped trimming and the AFR went very lean (16-17) and you could could here it running funny so I shut it down and upped the VE table (which I knew already was weird). I restarted and the AFR went back to normal and the combinedFT was down closer to 2-3%. But my VE cell at idle was 81% which I know is fuuucked. So I started diagnosing WTF is going on.

Back story: Freshly built motor with ~800km's on it. Still on break in mode. New everything: from guides to pan it got all the HD bits. Running a bit more boost since 500km's but no knock and my EGT's are in the 800-850C range. Not burning oil nor coolant. Rebuilt the Holset about a week ago or more. Tested out fine and running normal. Haven't done a comp test as the valves all got recut and I am waiting until ~2000km mark as I have read it takes quite a while for valves to fully seat in their new homes. All the fun bits and properly cleaned up and regasketed all around. Freshly rebuilt 1G NA TB about 8 months ago. I only have a few couplers on my intake as I welded where I could and put couplers where it made sense.


Sooooooo its running fine one night and the next morning not. AFR's were all bang on before and now its lean across the whole range. Literally looks shifted up by say 2-3 "AFR's".

So far:
- Fuel pressure? Since its shifted up along the whole range. Bang on. Clicked it on with DSMLink and checked. Still a rock solid 43psi right where I left it. Turn engine on drops down to low 39-38 right where it usually likes to site at idle. Give it arev up to launch limit and get a few lbs of boost and I can see my gauge rising about 1:1. Dunno for sure as I should log it but it looks right. Nope.

- Vac line popped off? Did a BLT to 35 psi. Holds it fine. Found one little spot where it was very slightly doing that foam thing at highAF pressures so I fixed that. Tested every connection, hose, BOV, WGS solenoid, TB, IM, and anything else seeing boost/vac signal. Notta. All sealed still. Nope.

- Fuel Leak? Checked all connections from tank to rail and back again. No leaks. Not on the injectors themselves nor on any AN connection. All fine. Nope.

- Plugged fuel filter? Pressures suggest its fine but I pulled it out anyways. Aeromotive rebuildable one. Pulled it apart and its pristine inside. Nope.

- Bad injector? Need to test more as all I did was shut off each one individually in Link and listened for a change in idle and I can confirm that change. They seem fine. Plus it seems weird that this issue pops up only after its warmed up and progresses slowly until its out of fuel trim.

- Bad O2 sensor? Well when it hit 16-17 at idle it sounded knockie. Knock sensor doesn't pick it up b/c its disabled below whatever the defaults are in DSMLink. It sounded like marbles in a tin can....like very lightly which I believe it what knock actually sounds like. Hence why I shut it off. Also I went for a careful cruise around the block and the AFR's are going lean and NOW it knocks at even light throttle and its got no power and the EGT's are high from the ECU pulling timing from the knocking so I feel like the AFR's are actually lean and the O2 is fine.

- Some kind of leak? Posible given the 20* temp change overnight. BLT showed nothing tho and I mean I checked from brake booster to BOV. Nothing. Holds a solid 35 psi with no leaks.

- On the leak thing....so it would be lean at idle and rich under boost but I am seeing lean across the whole range...boost or vac same lean condition.


Here's the weird part: If I turn down my fuel calibrated fuel trim from -73.8% to -67% (so that it injects more fuel than it should with a bigger pulsewidth then the AFR's line. I went for a crusie like that and it FINALLY builds boost and pulls hard. But again if I leave it like this then it slowly starts going lean and I have to change the global fuel again. To be clear I am just changing the global fuel to diagnose the problem...its not a fix and had already been reverted. Just need to see if it was in injector which by upping fuel I can see its not. I think it it was an injector then it would have stayed lean no matter how wide the pulse width but I didn't see that.

So this ALL leads me to either pump or AFPR. I haven't ruled out anything yet but this is where I feel the issue must be. It feels like a fuel delivery issue.

I saw a post about issues with an AFPR where there was damage inside from a little ball or something. Can't find the post now but if you know of it could you link me plz? I am gonna pull it apart now to verify its okay anyways.

I don't know how to test the pump (wally 400 with less than 20K on it) past what I have done. It sounds like usual. Normal amount of cranking at start up. Base pressure unchanged and where it always is. Idle pressure fine. What looks like a 1:1 rise rate. What other test can I perform on it?

I'm pulling the pump now to check its filter sock and check inside the tank to see if I got some bad gas and it gelled up inside the tank. I have fixed and cleaned small lawnmower engines that had some weird gelled gas in them but I am reaching for straws there.

I am going to blow out the fuel lines while I have all this stuff of to verify they aren't plugged and also pull the rail and the injectors and check their filter baskets too.

If AFPR looks fine and the pump/sock filter/gas tank are fine then anyone else got any ideas? I'm struggling to find more culprits after this.
 
I did try open loop. No change.

AFPR checks out internally. Looks new and spotless.

The pump however looks weird. The elec contacts on the actual pump look corroded like a battery almost. That white crusty shiiiit excpeted soaked in gas.

I solder all my connections so its puzzling.

Also they look overheated... But i usuly fuuuck those plastic covers up when i pull em back to solder so i dunno if its that cause if its not.... Wtf.

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Okay this is reeeeal weird now. I picked some of that stuff of the contact and its like white plastic... Kinda. Its pliable anyways. Not crystally like batt corrosion. Where/what is it? Man thats weird....

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Mods: i know im double/multi posting... Merge if you want my hands are cold and its a lotta trouble shooting out here. :)

Thought: the gas has been eating those crimp connector plastic and the half "melted" gas/plastic sludge is dripping down and got between the contacts...?

Is there any issue with soldering the wires directly to the pump? Not as friendly to replace but elimates the elec connects.
 
LOGS NOW ATTACHED

Fuel pumped direct soldered. No change. Starts up fine but after a min or 2 it starts leaning out.

Changed AFPR's and reset base fuel. Also cranked up the base fuel to 85 psi to see if the pump could reach it and it did. Turned back down to 43 psi and restarted. No Change. Starts up fine but after a min or 2 it starts leaning out.

I recalibrated the O2. No change.

I watched the fuel pressure gauges on both AFPR's (different gauges on both) during this leaning out and it did not change or drop or anything.

Also I am not seeing any change in the MAP sensor either.

I attached logs. I thought I saw a pattern with the ISC so I unplugged it and cranked the BISS closed. No change. I did notice I couldn't get idle below 900 but I think the ISC was half open when unplugged. Plugged ISC back in with BISS closed and it stayed at 60-80 but idle didn't go much down. I think ISC has lost control of idle maybe? I dunno. The AFR's are swinging widely so I need to address fuel first.

THESE are all open loop logs to eliminate the NBO2

Every time it starts up rich b/c I have the VE cranked at idle a bit to keep it on the good side of 14.7 longer. It stays about 11.7-12 for 1-2 mins and then slowly starts climbing. Remember this is with LOCK OPEN LOOP on.
 

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One of the logs i switched the injectors on and off 1 by 1 to look for a pattern there. Dunno which log. Thought i saw something on cyl 1 so tried it a few times more and saw no pattern.
 
I had this happen to me when Arizona changed e85 to e54. Had it not been for these forums I wouldn't have realized they changed the fuel on us. Had to make quite a bit of change to my global to get my afrs to line up again. Dumb question but did u fill up in a different place or recently?
 
Have you tried locking the coolant temp sensor?

No, i havent but i will try that next. What you thinking?

I had this happen to me when Arizona changed e85 to e54. Had it not been for these forums I wouldn't have realized they changed the fuel on us. Had to make quite a bit of change to my global to get my afrs to line up again. Dumb question but did u fill up in a different place or recently?

No, my usual corner store. Lucky to have one of the few spots with 94 a half block away.
 
Took a break last night and thought about it this morning a bit and I think I've got it narrowed down to the fuel pump is kind of dying as it warms up or one of the injectors is doing something similar.

What are the symptoms of a dying ISC? I dont think its that tho as its lean in boost too... but it is acting strange from the logs.

Anyone got any other thoughts or ideas for testing stuff inspecting stuff whatever? Like any ideas at all? I'm having a tough time narrowing this one down.
 
What’s the fuel pressure like after awhile?
It stays at 37-38psi at idle with vac cconnected. Stays there right from start up to where it starts leaning out to where i shut it down b/c its to lean. I watched that gauge on both AFPRs (each have their own gauge) and they both showed steady pressure throughout the test.

I gues i could hook up an ammeter and watch the pump amps and see what they do.
 
Well if it was getting hot and then slowling down then it would show it on the fuel pressure gauge. Are you running speed density?

I'm on proper SD. VE was all dialed in too. Needed work in the low boost/vac areas, but idle was not what it is now. Timing hasn't been touched and was very conservative b/c I juuust was finishing my VE table.

Tried locking coolant temp but the car is very cold and it runs super super lean almost immediately.

I just swapped fuses on the fuel pump (its rewired direct to bat via relay) as the one in there looked a little dirty/old. No change. In fact its worse this morning. AFR's start climbing almost immediately.

It's colder this morning too ( -17*C) so I'm trying to think what would not like a temp change: First thoughts are relays but those fail on off and I have a slow rise. The fuel pump comes to mind but I think you'd see the pressure drop on the gauge. Also if it was a vac leak I think I'd see MAP changes at the leaning out start but I don't.

I just put in a new Omni 4bar GM style in 2-4 weeks ago. I don't think that would fail but I'm gonna swap in my GM 3 bar and verify its not that either.

I'm really running out of ideas now and I don't wanna throw $$ at it b/c that never works out well if you don't know where the real prob is.

What are the symptoms of a failing injector? To me, if it was plugged/clogged it would be doing the lean thing immedately and not a slow rise.

What are the symptoms of a failing/leaking ISC?
Mine is acting weird and I did BLT test it but maybe its leaking inside somewhere I can't see/get soapy water too.
 
Pulled the plugs... They look okay-ish for the rich/lean issue im trouble shooting.

However, the tops of my pistons look like shiiiit. I can see some kinda black sludge on top. Like crazy carbon build up. Theres only 800kms on them so far.

2 things come to mind now. Bad gas or maybe i got the last of the summer gas or contaminated gas....OR the VC is sucking in a ton of oil.

I have the VC vent hooked up to the intake mani. Im running a cyclone mani properly actuated. I have a 10AN line running from VC to catch can then from can to turbo inlet. I have a pressure sensor on the inelt and under full boost at high RPM's the intake on the turbo never gets much or at all below ambient.

Im thinking: plug the intake to VC line so its not potentially sucking in oil and draining the gas tank and getting fresh gas.

Heres a pic of one of the pistons and sludge. For only 800 kms that is suuuuuuuper weird. Im not burning oil either. I was on initial startup but thats from the motor assembly and stopped almost immediately. I did use a ton of oil when rebuilding the holset and it smoked like a mofo till all that was burned off and again fine ever since.

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The others ones have very similar looking build up but this one produced the best pic.
 
Wow that pic didnt load well. Looks good on the phone. I'll try and upload again as that sludge is my immediate next concern.

Alright.... so I went to drain the tank and used Link to click on the pump and it was flowing awesome for the first few mins and then its flow just gets anemic. You can hear the pump working tho its almost like its starved on the inlet end up the pump.

I think i've got it narrowed down to the pump side of things for sure now. It sounds off or something once it got to the "weird" area and its flow is shiiiit. Also the gas doesn't smell as "gassie..... 94 stinks compared to 87 and this is not that strong smelling.

It's about the right timing too....a few mins in and the flow just drops off.

Would a plugged up inlet sock do that? It looked fine when I pulled it but it is micron sized mesh I think so maybe it is plugged....although I kinda think it would do it immediately if it was.
 
I know this sounds kinda terrible. Lol but take the sock off and take the fuel feed off the left side of the rail then see if it does it again like you mentioned. If it’s does then I’d change that fuel pump.
 
I know this sounds kinda terrible. Lol but take the sock off and take the fuel feed off the left side of the rail then see if it does it again like you mentioned. If it’s does then I’d change that fuel pump.

I'm swapping in the pump from my parts car. Juuuust got it out now...... im warming up my hands then its going in.

Luckily its a Walboro 190 (had no idea what was in there...so yay hahah) which will suffice to test and see if I have the same issue on a diff pump.

I keep clicking the pump on after giving it a break while im doing other stuff and its erratic with how long it will flow for before it drops off. Sometimes 10 sec's other times 1-2 mins or anywhere in between. It sounds like its being loaded up or rather starved of fuel when it does drop off tho.
 
I hooked up a short bypass hose (to isolate just the pump from the car) to the outlet on the sender unit and shot a video of the flow.

Like I said.....good flow and then tapers off and the pump sounds loaded or starved or something.

There is a pressure relief on the wallys right.....where/how do I check that?

In the video you can see at the start how "strong" the flow is and then it just tapers off for some reason. There is 3/4 of a tank of gas still so it's not that. It's gotta be the pump right?

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That’s a bit rediculous.let us know how it is after swapping them out.

So its not just me. That is mos def tapering off for some reason hey?

Will do. It's just so damn cold out and I have the heaters off in garage b/c of the huge amount of gas fumes so I'm dying of cold fingers. Hahaha.
 
Have you verified there isn't a voltage drop to the pump when this occurs?

No i havent. Are you thinking maybe the relay might be the culprit? I kind of was thinking I should test that before I tear the pump out again.
 
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