Possible e85 sticky death

[PolishMs3]

So let me start this by saying I don't know what caused my issue but I feel that it could be related to the e85.
About 3 months ago I got an OTS e85 tune the whole time the car has ran great until 2 weeks ago. I went to Cali for a trip and switched to 91 the whole time. When I came back and filled with the e mix the car ran great for about a half tank and then started to act up.
When I first start the car and leave while it's still somewhat "cold" I'm getting fluctuation in fuel pressure and the car begins to decelerate while I'm still holding the gas. It is only after switching into 2nd 3rd or 4th gear, low Rpms, almost no load just regular driving. It is pretty subtle, but when your driving it is very obvious.

There was one time that I started the car and it kept backfiring/popping and the fuel pressure was sitting at 200 psi but after that one time the idle seems normal at around 400 and full throttle still seeing 1700+ psi.

I pulled the spill valve off and cleaned off the thin brown film/residue but this has not fixed the issue..do I need to pull the hpfp apart and clean that as well?
Or is there something else that I should check into.
Any suggestions are appreciated. FYI I changed my plugs recently and still on stock heat range

[sheston]

When you changed your plugs, what did you gap them to? 26-28?

What mods do you have? Miles on the vehicle? etc. Try to log it, that would help.

[PolishMs3]

Originally Posted by sheston When you changed your plugs, what did you gap them to? 26-28? What mods do you have? Miles on the vehicle? etc. Try to log it, that would help.

28 just Sri tip hpfp test pipe Cbe and about 58k miles
I'll try to get a log when I drive it home. Once it's warmed up or I've punched the throttle a couple times it goes away.

[Djohns]

I would also check EGR

[MRR]

If your spill valve has that black or brown residue in it, pretty sure your HPFP is full of it. Pull the whole thing out and clean it well. Read on the how to clean HPFP.
Make sure you pull everything apart and clean it all.
Mine was the same. I used carburettor cleaner to remove the residue out.

[PolishMs3]

Originally Posted by MRR If your spill valve has that black or brown residue in it, pretty sure your HPFP is full of it. Pull the whole thing out and clean it well. Read on the how to clean HPFP. Make sure you pull everything apart and clean it all. Mine was the same. I used carburettor cleaner to remove the residue out.

Spill valve didn't have much in it, it did have the VERY thin brown coating on it but rubbing a Q tip with fuel on it got that off with no effort so I thought the hpfp would be fine, I was saving that for last since when I installed it I had a hell of a time getting the main fuel line to pop into place.

Is it possible this could be a failing 02? I have a hard time believing my hpfp is clogged after only a few months of e40.

Still working on posting logs, been super busy with work and its also not the easiest thing to log cause it doesn't happen ALL the time.

[g00s3y]

Trust me, even a thin film can mess up the internals of the HPFP. I had my car sit for about 2 months with an e33 mix. Long story, injector seals, blah blah blah. Get it running, and couldn't hold pressure well at WOT. Spill valve was fine, internals had only a very thin film on them, but it was enough to drop to <1000psi at WOT.

[PolishMs3]

Originally Posted by g00s3y Trust me, even a thin film can mess up the internals of the HPFP. I had my car sit for about 2 months with an e33 mix. Long story, injector seals, blah blah blah. Get it running, and couldn't hold pressure well at WOT. Spill valve was fine, internals had only a very thin film on them, but it was enough to drop to <1000psi at WOT.

Yeah I got some time this sunday so ill just pull that apart then, its just the strangest thing, Once I get on the gas and the car warms up a bit it pulls like a greyhound with the squirts, with the fuel pressure 1700+ on WOT. when I am just light on the gas while the car is still cold is where im getting issues, ill even see it drop in fuel pressure a couple hundred psi but then not even a second later it comes back.

Ill be posting logs tonight

Originally Posted by MRR You switch from an E85 to 91, did you change your OTS too??? What are your AFRs, LTFTs Get some logs.....

AFRS are fine 14.8 idle 11.7 WOT on e85 tune LTFT between -2 to 5. So still within the "acceptable" range.

I just switched back to full 91 tune because I read on a thread that it solved the issue but in my case it did not...

the gas tune is from freektune and the e85 OTS from Stratified so I don't think it has anything to do with the tune.

[MRR]

You switch from E85 to 91, did you change your OTS too???
What are your AFRs, LTFTs
Get some logs.....

I ran 50% E85 for 1.5 months and got a thin film of residue on my spill valve which was cleanable with cotton bud tips. When I pulled my HPFP, it was worse than I thought. The piston was covered with this sticky brown residue. Also other parts of the pump was all affected including diaphragm.

[PolishMs3]

In case anyone cared or anyone had similar issues, I went ahead and pulled the plugs one more time. This time instead of using a cheap coin type gap i used feeler gauges and realized it was gapped to .025 some even less. I re gapped all the plugs to be .028-.030 and Violia!! The problem is gone....for now.

[sheston]

Interesting, first case of too little gap!

If anyone understands why plugs would affect fuel pressure, let me know. Maybe I'm just having a brain fart, but doesn't make sense to me

[PolishMs3]

I don't that was affecting my fuel pressure, after I cleaned spill valve my fuel pressure was always normal just always hesitated under light acceleration just felt like a fouled out plug. Now that I stretched the gap open it has seemed to stop the problem. I have only driven 100 miles so far so idk if it will come back

[swd120]

Pull the pump, clean it with Redline SI-1, then switch your oil to Royal Purple Dexos2 - no more black death even if you run pure e85!

[PolishMs3]

Originally Posted by swd120 Pull the pump, clean it with Redline SI-1, then switch your oil to Royal Purple Dexos2 - no more black death even if you run pure e85!

So I pulled apart the pump cleaned with sI-1 switched to RP and I still have this issue, Its not as noticeable now but it has its moments. I am at a loss and about to revert back to stock so I can have Mazda take a look under warranty.

Anybody else have any suggestions before I have to do this. It might be worthwhile to mention the car has 60k miles on it and to my knowledge has never had the intake valve cleaning done. Could this contribute to drivability issues?