Please Help, Major Tuning Issue

[3052Talon]

Hey guys,

I finally got on here, and have a major tuning issue with my 1G.

I just upgraded to speed density and V3 because of a connectivity issue with V2.5 and the GM MAF. When I bought the car from a friend it ran fine, but could not connect to DSMLink at all. I cracked an intercooler end tank, and brought it to the shop to tune and fix the leak.

The repair went fine, but we still couldn't connect. We did a baseline dyno and the car was fine until it hit WOT loop. At that point the A/F dipped really really rich and stayed there. It was dumping fuel like crazy. It needed a tune ASAP. The decision was made to troubleshoot. The connections from the port to ECU were examined and tested, all was fine. The ECU was sent out to ECMLink and upgraded to V3. When it came back, it connected, but we couldn't connect with the MAF translator (obviously, that solution is unnecessary with V3), and we decided to ditch the MAF setup altogether.

A MAP sensor was installed as well as an IAT sensor. Speed density would allow me to run meth without any risk of getting the MAF wet, or having to redesign my charge pipe.

Here's the main issue: I have a switch to turn the fuel pump on and off. Everything reads as if it connects on Link, but the car won't start unless the fuel pump is off. Then it starts and idles off of the fuel in the rail/lines, but dies as soon as it is given gas. Wtf... the car is mechanically sound, but I have no idea how it's drawing fuel from the lines when the pump is off.

Is link taking commands, but not translating them into actions with the hardware (injectors?). No cylinder is flooded with fuel. I do no believe that the injectors are stuck open. They just don't seem to respond to commands. My shop thinks it's an issue with Link, or my ECU. When ECMLink looked at the ECU they said it was fine and installed V3. Could V3 be bad?

Any ideas are helpful. We are all stumped...

 

[STI EATER]

Did you do the fuel pump wiring? Is it a strait run from the battery or the relay and is the stock fuel pump positive line being used? I would look at the wiring job because a hot wire grounding out can screw with your ecu and alternator. IDK what else. Check all ecmlink settings and hit save. (K.I.S.S)

 

[turboglenn]

take a manual and wire the fuel pump back up the way it was from the factory, then there's nothing to worry about and you might find the problem that lead to the rigged pump setup to begin with and solve that too... there's no reason it shoud'nt start with the pump on, if in fact it "CAN'T START' with the pump on due to no spark or something shortedm then the relay you're triggering the pump with is hooked up wrong to soemthing or the power is pulled from a bad source... you should run it like factory, then run a new power wire from battery to a relay in the rear by the tank that the OEM pump power wire triggers as if that relay were teh pump, then all problems will be eliminated

But again, i almost bet it will start with the pump on, itr's probably just gettign too much fuel and flooding, hold the gas about 3/4open and try and start it, let off as soon as teh revs start to climb after starting if it starts... if it doesn't start, turn the pump on and check for spark becuase that's the only thinkg you'd be missing from the 3 parts to make an engine run (fuel, spark, compression)

 

[snowborder714]

Where is the switch tapped into to turn the pump on/off?
As others have said, have you verified the pump wiring?
Where is your MAP getting its boost source from and how is that plumbed (single short line direct to intake manifold, long line teed into another line, etc.)?

Can you post up a log (can be taken with car off, but key ON if you can't keep the car idling) so we can validate your settings?

 

[3052Talon]

snowborder714, thanks for the tips. The car is currently at the shop, but I will try and get them to forward me some info ASAP.

If I have time, I might try to do it myself today, or tomorrow. The shop thinks it's an issue with the ECU, or the V3 itself, but I want to make sure it's not an issue with the pump & associated wiring. I am not familiar with the wiring setup as the previous owner did that, but I will text him and try to get an answer. The switch for the pump is wired directly to the battery.

My understanding is that the car started with no problems before speed density. This issue only came up after the switch to V3 and SD. SD is not overly complicated to install. Could the shop have made a mistake somewhere?

I can confirm that something is PULLING fuel from the tank when the car is shut off. The shop confirmed that it's not pushing.

Working on getting some sort of progress.

The more I think about the issue the more confused I am. I have no idea what's pulling fuel when the pump is shut off. I have 1000cc injectors, but that's not anything extreme.