Ok, so as some of you may know my freshly spruced up Evo 9 is having major drive-ability issues as well as stalling out. I will try and lay everything out so it's easier to follow.

Car was on 93 Oct, MAF tune with full bolt ons before.

Things that were changed/upgraded.

MAF Dyno Tune 93 oct-> Speed Density Dyno Tune on e85 and 93 oct
Stock MAP Sensor --> Omni 4 Bar MAP
ETS MAF Intake --> STM SD intake
Tial QR BOV --> Tial Q BOV
Stock TB --> S90 TB
Stock Intake Manifold --> CB Ported w/ 70mm flange
Stock Exhaust Mani --> FP Race manifold
Stock 9 Turbo --> FP54 Green
Stock Fuel Injectors --> ID1300 injectors
Complete Fueling upgrade, wally 450, STM FPR Kit w/ radium pulse damper, Radium fuel rail

Tuning went perfectly, I went to pick the car up and drove it less than 1 mile. During that mile it stalled out 5 times when coming to a stop.
Drove it back and we ended up determining that the stock 02 sensor must have died, unplugged the 02, ordered a new one and drove home relatively fine.

(O2 sensor: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1)

New O2 comes in, swap it out and drive back home again. Drive-ability now is super pronounced. Figure Mayyyyyyybe it's the IAC which has been going out for a while now. So I ordered one of those (OEM). Bear through the drive-ability issues for a few days while the OEM unit gets here and swap it in.

No change..... not really surprising.

During this whole time the AFR gauge was reading all over the place, from off the gauge rich to off the gauge lean with complete injector cuts in between.

Take it back to the tuner who pulls the logs and specifically the MAP sensor log.
MAP sensor data is all over the place with tons of noise. A-HAH! we think, Omni has been having sensor issues recently so I go ahead and order another one while my tuner works out an AEM 3.5 bar solution.

Get the New Omni in and easily swap it out.... problems are now WORSE.
Any bumps or changes in pavement cause the car to bog or run lean, sometimes with injector cut.

Drop it back off at the shop where we all agree it must be a wiring issue, turns out the MAP sensor harness had been spliced!! Excellent, probably just needs a better wrap up job, shop does that and BAM

Nothing changes.... they even noted that shutting the hood or closing the driver's door cause the car to cut out.

Myself and the shop are at a loss right now, we both feel like it's a wiring issue but have no idea what would be the best place to look next.

ANY help or thoughts on where to check would be great

 

So.. your car was fine until you got a retune with more parts? Thats a tuning issue my friend, and if a tuner cant figure out whats going on with the cars he tunes, you need a new tuner my friend

 

This is on the tuner, if you brought them a car that ran fine and they let you go home in something that barely runs at all then thats a big red flag in my book.

Most electrical problems tend to be grounding issues, so check all your grounds make sure they are tight. Check your battery terminals make sure they are nice and clean/tight. How is your fuel system setup? Is it hardwired, did you use a hobb switch for the hard wire or is the thing getting full voltage all the time?

 

Fuel pump is hard wired with this kit from radium: http://www.radiumauto.com/DIY-Fuel-P...-Kit-P368.aspx

No hobb switch.

 

If the pump is running full tilt all the time that could be over running your return. Do you have a way to monitor fuel pressure at the rail?

 

yeah there is a pressure gauge on the front of the fuel rail. We did some testing initially to see if there was a pressure drop when the throttle body was moved by hand and when throttle was applied. It remained constant the whole time but I don't have an in car pressure monitor if that's what you mean?

I appreciate the replies so far guys.

 

It is because of the fuel pumps running at the same time. I had that experience with my talon many years ago before i knew about the hobbs switch. It is over running the system being there running at the same time when they don't need to be. Take one out of the system and I bet it clears up. If so that is your problem.

 

ahhh I should have been clearer, it's a single walboro 450 pump in the car, so no second pump to worry about.

 

Have you tried to swap the new injectors with the old ones? Was the work done by you or the shop? (if previously stated I missed it)

 

No it was my bad on that I misread lol. I tend to do that when I am tired. My suggestion would be since you replaced all the map sensors and what nots is to have someone go back through all the wiring and make sure everything is in the correct spot wiring wise. Like you said maybe loose wire, or maybe a ground not in the right spot or something stupid like that I know we all have been there at least once. But it does sound like a loose wire somewhere or poor connection.

 

Haven't tried to swap injectors, would probably be tough since it went from stock ones to the ID1300s but I'll bring it up. I would also be surprised if the new injectors were an issue, they cost an arm and a leg. All the work was done by the shop.

No worries, but yeah that's what I'm thinking right now as well, it's got to be a loose wire somewhere, I just have no idea where to start.

 

Even quality parts have issues sometimes. If the injectors connections are bad, could explain hitting bumps or slamming the door. Trying to think out side the box here for you. Lol

 

Very good point, I'll have the shop look into it!

 

Knock sensor? CAM angle sensor? Crank position sensor?

Just options but it sounds to me if your car was running perfectly fine before the mods and now it runs like total poop, sounds like 90% rule. Can you post your logs?

 

Big Update!
I know it's been a long time but the issues have finally been sorted out!

Kudos to the guys who said wiring issues, turns out that was the culprit! I kept noticing that when it was cold out, the issues seemed worse. Let the car idle for a bit and warm up and the issues got slightly better. The shop kept having a harder time noticing it because they would fire the car up and let it sit for about 20 minutes.

The specific culprit was the wiring at the ECU, both the shop and myself think that the Previous owner must have run an early style Standalone ECU. Early style meaning early on in the Evo modifying history before the secrets of the Stock ECU were discovered. These earlier style units involved much more engine harness splicing, so when the PO returned the car to stock and had to re-wire a lot of things, he did a **** job.
The wiring at the ECU was so loose that the technician that found it was amazed that the car even ran at all. If he moved the ecu even the slightest, the car would stall out. This explains why going over even slight changes in the pavement would cause issues.
Wiring issues were also exacerbated by the temperature with the loose wires expanding in heat and contracting in cold. (I know, I know, but Jmills, the linear expansion coefficient of copper wire is so small that you would hardly notice it over the temperature range you probably had. I guess that's just how small the difference was between a good connection and a bad one

Anyways I hope this helps some poor soul in the future, I wouldn't wish this situation on my worst enemy.