b16a95eg

iTrader: (12)

Just wondering in anyone else has had the issue I'm having.
I'm having startup/idle issues which I don't think are tune related but something else. During startup the car cranks a lot longer than it did last year. And will pop/a few times before it finally starts.


Once it does start the only way it stays idling is if I give it about 15-30% throttle. Otherwise it just slowly sputters out. It does this with my previous tune on the stock ecu. I also have an AEM Series 2 with a tune on it from a very close set up to mine.


A couple things changed on the car since it was tuned last year (Buschur 280 cams instead of s3's, Buschur head, though I had a similar built head in it last year, I went to a walbro 450/450 instead of the 255/450 I had last year, siphon was drilled to 9/64 , injectors were sent in to FIC for cleaning too)


There's no boost leaks, compression was 150 across the board, fuel pressure is 43 psi, I'm getting spark and fuel obviously since it finally starts up, the map sensor was reading correctly through the wiring, and then verified on the AEM, 1.28 volts with the engine off key on. Timing is on. I swapped cam sensors with a known good one. Didn't change. The bigger vane is pointing at the 5 o'clock area with the engine at TDC when you're looking at it from the driver side. The only CEL that popped up was a p0500 which is odd, the speedo works fine, I even drove it around the block. It seems to drive fine just stumbles anything lower than 2000rpm.

The plugs are black and wet with fuel. i've gone through 3 sets, and even with new ones in there it does the same thing


The car is an Evo 8 on e85. Stock ecu speed density and I have an AEM series 2 also same issue on both Ideas. I'm out of ideas. I'll try to get a video up here soon

https://www.youtube.com/watch?v=Y68a...ature=youtu.be

RightSaid fred

Fuel pressure is 10PSI too high, that's if you're measuring at idle with the vac line still on.

b16a95eg

iTrader: (12)

I played around with the fuel pressure a little bit and it didnt help :/ this is where it was set last year when it was tuned on a similar set up.

First post edited with a video

b16a95eg

iTrader: (12)

Well it wasn't fuel on the plugs, but a thin coat of oil on all of them. So i'm guessing maybe valve seals. They're the supertech ones people have had issues with in the past. I did get the smaller ones though that fit with dual springs so who knows, i'm going to get another set of them and change and recheck everything.

The head gasket was either leaking or I have a crack in a coolant jacket somewhere too. I drained the oil and it was milky... fantastic

RightSaid fred

So you're outflowing the regulator.

As the engine load increases, the pressure across the injector drops, it leans out.

It can't be tuned like that.

You'll end up detonating due to being too lean..........broken pistons.

b16a95eg

iTrader: (12)

I have an Adjustable regulator on it, I dropped fuel pressure down but it still did it. I guess I was a little vague in the OP but its a built engine/head too.

I found some oil in the combustion chambers and milky oil. The block is O-ringed so I'm assuming it had an issue sealing even though compression was good something wasn't working as intended. I have a new headgasket and was told to try and torque it down a few ft lbs more and try again. I'll report back in a day or 2 and see if that helps

b16a95eg

iTrader: (12)

Re-Torqued the head and that fixed the oil in the combustion chamber/coolant. And found the issue of the idle. It was a mix of needing tuning and the way I had some wiring issues that ended up back feeding some voltage to the 2nd pump which ended up causing fuel pressure to go too high/and dumping to much fuel in.

I feel once I put my 255 back in the first time the misfire was from the oil getting in the cylinders and still needed a little touch up on the tune