Anyone Have Issues Doing A Smoke Test? Car Won't Run

[94CobraWA]

I have a 94 Cobra with a Vortech. I recently installed the Anderson forced induction kit - TFS heads, B31 cam, Holley Systemax intake). Started right up and idled well and drove around the block well but AFR was pegged at 21.0, super lean. I suspected a vac leak so I did a smoke test and smoke came out both freeze plugs of the Holley intake and out of the spring of the BBK throttle body. I put the stock throttle body back on and sealed up the freeze plugs.

Ran another smoke test and no smoke came out anywhere. Went to start the car and it would crank with a loud screeching noise and would idle really rough. I have to give it gas or the car would stall. AFR at idle is now around 11.0, super rich. The plugs fouled obviously. I changed the plugs, started it up and they were fouled within 30 seconds. I pulled both narrowband and wideband o2 sensors and they were all charred. I thought maybe the o2 sensors got damaged from the smoke test and were causing the rich condition so I installed new narrowband/wideband sensors and new plugs, and same thing, car idles terrible. I don't want to run the car anymore and keep replacing the o2 sensors/plugs until I figure out the underlying issue.

Car has new 60 lb injectors, I don't see any visual fuel leaks, no fuel coming out of the vac line from the stock fuel pressure regulator. Fairly new Walbro 255 fuel pump, pump primes when ignition is turned on. EGR is deleted, ground on the driver side is new. New starter/starter solenoid. I am using Quarterhorse and a new tune from Lasota Racing which is already downloaded for the new setup.

 

[90sickfox]

Have you tried adjusting the throttle screw ? If it isn't letting enough air in the engine it could cause a problem.

The surprising thing is " screeching ". I've heard throttle blades make some whistling noises....but never a screech. Some people get a whistle from the IAC valve.

Does it start with pressing the gas pedal ?

Seems like its running pig rich. If the previous tune was burned with too much air ( vacuum leaks ) it could cause the fuel table to be rich once vacuum leaks are fixed.

Have you contacted Willie Lynch at dirtydirtyracing.com ? He's the best guy I know of with QH tuning.

 

[94CobraWA]

Have you tried adjusting the throttle screw ? If it isn't letting enough air in the engine it could cause a problem.

The surprising thing is " screeching ". I've heard throttle blades make some whistling noises....but never a screech. Some people get a whistle from the IAC valve.

Does it start with pressing the gas pedal ?

Seems like its running pig rich. If the previous tune was burned with too much air ( vacuum leaks ) it could cause the fuel table to be rich once vacuum leaks are fixed.

Have you contacted Willie Lynch at dirtydirtyracing.com ? He's the best guy I know of with QH tuning.

It's running rich for sure at idle, between 10 to 11 afr on the wideband. Car starts without the gas pedal at times, others I need to give it gas. I haven't touched the throttle screw, it's the same oem throttle body I ran before the HCI and it ran fine so I don't think that's the issue. It shouldn't be in the tune, this is a base tune that is pretty much in line with what I had originally w/ the Vortech, minus the adjustment to upgrading from 42 to 60 lb injectors and readjusting for the egr delete. What's funny is before the smoke test, the car idled great even with the vacuum leaks.

 

[90sickfox]

It idled great because of the vacuum leaks.

You may have to adjust the idle screw in a little, readjust the tps to 1 volt. It ran before you put all the stuff on that needs more air. Let me guess...the bbk was a 70mm tb ?

The stock one is only 55mm or 60mm...not sure about the factory cobra tb.

That camshaft probably needs more air than its getting through that tb....that's only a idle screw adjustment.

Are you sure the QH is fully seated ? Did you hook the o2 sensor ground to the firewall behind the intake ? ( I don't even know if the cobra grounds the o2 sensors at the firewall )

Just trying to help. A few guys here know way more than me. They'll chime in eventually.

 

[billison]

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[Steel1]

Sounds possibly tune related. You mentioned the tune is new but how old is the battery in the quaterhorse?
If battery is good I would plug in your laptop and look at the tune.

 

[FoxMustangLvr]

You should put on another TB that is suitable for your combo and tune. Is your current tune setup for the 60lb injectors or the old 42lb injectors? I think your problem is tune related and you should get the people on the phone and talk to them about your issues. Maybe your injectors are dumping too much fuel which would need to be corrected in your tune. Running too rich will kill your O2 sensors. Are you capable of data logging? If not, you should. It helps with diagnosing problems and refining your tune.

 

[revhead347]

What's your fuel pressure at? Might have to drop some fuel pressure to see if that helps. Good call on the smoke test.

Kurt

 

[jrichker]

Do the basics first....
Dump codes sticky

Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. Codes may be present even if the CEL (Check Engine Light) isn’t on. You don’t need a code reader or scanner – all you need is a paper clip, or if your lady friend has a hair pin, that will do the job.
I highly suggest that you read it and follow the instructions to dump the codes. http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/

Then post your numeric results here and I will give you what the codes mean and how to fix them.