Rough Idle Stalling Popping Video

[3sienvy]

I took a video of what my car (97 vr4) does on start up. It has a strong crank and turns over almost right away. Soon after starting up it dies unless you push the gas pedal. It is all stock that i can tell, it does have a k n filter on it.

I searched through the forums and reviewed write ups on the ISC, IAC, Spark Plugs and Wires, Boost Leak, Vacuum Leak, Injectors, Fuel Filter, ECU etc

I ran down the boost leaks and fixed them. All the vacuum hoses are attached where they are supposed to go (except for the clutch vacuum lines)

I removed the Spark Plugs and inspected them (the slightest bit of oil on the last lip and smelled pretty heavy of gas)

Can someone look at this video and from the sound (the popping and the choke) and then under throttle when there seems to be a "skip" and point me in the right direction.




Anyone thinking this is electrical or ECU? Reason being i have some open plugs near the front right firewall (and some hacking near the ECU harness) and i dont know what they plug into (pictures attached)

Thanks in Advance. (apologies for the shaky hand while video taping)

ECU-pic.jpg

firewall.jpg

Intake-Manifold.jpg

[3sienvy]

Does anyone know where the wires near the firewall are supposed to be connected to they have different colored harnesses but they are just laying open.

Any ideas would be great.

Thanks

[Hannibalzero]

I didn't watch the vid, but based on the popping symptom I would pull off the plenum, make sure something didn't get caught between the upper and lower plenums (like a wire), and reseat it. My plenum would not sit correctly because one of my engine brackets was propping it up slightly - this generated a popping sound every time I tried to start the car.

Also, while you have the plenum off, check to make sure the wires are correctly ordered.

[netmechanic]

Some of those connectors are for diagnostics in the one pic, there supposed to be hangin loose

[3sienvy]

Originally Posted by netmechanic

Some of those connectors are for diagnostics in the one pic, there supposed to be hangin loose

ok, thanks i wasnt sure if this was leading to my rough idle or not, something like a tps connector or egr connection etc.

[Mike-92RT]

that sounds almost a lot like my stealth... its pissin me off and im lost

[gltasn]

vac leak check. i bet you have a leak or 2. might be a big one to make the pop. j sin

[3sienvy]

Originally Posted by gltasn

vac leak check. i bet you have a leak or 2. might be a big one to make the pop. j sin

i bought one of robecks pressure testers and i ran down and fixed some minor leaks. I did the soapy water test around the y pipe mas bubble tb ic's etc.

The tb gasket is installed the correct way but it sounds like there is a lot of air coming out around the tb. Any usual suspects in that area? I cant diagnose any more with the soapy water or just going by sound because nothing is happening with the soapy water and its hard to pinpoint the sound even when its dead quiet. (sounds like under or on the side of the tb)

I can pressure the system to 7psi, no further, and then it leaks out within 15 seconds.

[BjornRune]

Yeah, sounds like you have vac leaks. The TB shaft o-rings are prone to cracking -> leak. Also check the o-ring on the BISS screw, I had major leaks in my TB assy so I disassembled it and resealed everything with new o-rings and a new gasket. The leak around the TB shaft on my car was really bad, but you should be able to identify it (them) by pressure testing and spraying with soapy water.

7 psi sucks bad, I can easily hold 15+ psi for more than 15 secs so you have some significant leaks somewhere. Check the EGR tube and system as well if you haven't already done so.

Good luck and happy leak-hunting!

[3sienvy]

Originally Posted by BjornRune

Yeah, sounds like you have vac leaks. The TB shaft o-rings are prone to cracking -> leak. Also check the o-ring on the BISS screw, I had major leaks in my TB assy so I disassembled it and resealed everything with new o-rings and a new gasket. The leak around the TB shaft on my car was really bad, but you should be able to identify it (them) by pressure testing and spraying with soapy water.

7 psi sucks bad, I can easily hold 15+ psi for more than 15 secs so you have some significant leaks somewhere. Check the EGR tube and system as well if you haven't already done so.

Good luck and happy leak-hunting!

Great info. I was starting to speculate i needed to rebuild the tb with new o rings seals, #8 from home depot right? Thanks for the pointers