92 talon with a rough idle after head install

[cobra04]

Hello guys. I bought this car from some kids in union grove. It had a belt noise, but I didn’t really worry about it. Next day belt comes off. The water pump took a shit. I replace the pump and timing belt. I messed up on the timing belt, and bent to valves. I pulled the head off, and the machine shop took care of the rest. Put everything back together. While doing so I got rid of all the emissions stuff. It was missing hoses anyways and it doesn’t even have a cat. It has a 3in down pipe. I made sure I plugged everything and check for vacuum leaks every where. Now my problem is a rough idle at lower rpms. As of right the now I have a rough idle as soon dips below 1000 rpms. When I start the car up, the rpms will shoot up 2000rpms and bounce around a little (1000-2000rpms). Then it drops below 1000 and starts to idle rough, maybe a little surging but not all the time. For the last couple of day’s ive been doing research on vfaqs and dsmtuners.com. I still have to check timing and do a compression test. But things I did so far was replace the spark plugs, check all vacuum lines, check for codes with my snap-on scanner, and rechecked my timing marks, all good there. I did fine a wire that was arching put black tape for now. I’m still doing research and will do some more. I don’t know much about DSM, only mustangs. So any help will be thankful.

ps- will have videos later

Thanks
Jesse

 

[cruisintalonawd]

How low does it sit at an idle

 

[cobra04]

when it does idle its around 800-900

 

[cobra04]

i have 2 videos.I know i have a exhaust leak somewhere under the exhaust manifold. I will check that out at work, when i get it on the lift.

BTW it does feel like its missing.

video of the engine

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video of the exhaust

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[ktmrider]

Classic signs of a vacuum leak.
Had similar issues on my Talon, found a big hole in the BOV line nearer the valve. Also found the PCV hose was off and plugged ( from the head side ) and a cheasy rubber plug in the IM. Once I had everything hooked up and sealed the car idled great and did not die out.
Run a compression test to make sure you don't have a valve hanging open, it will also cause low vacuum readings and feel like it's missing.

 

[a_flint87]

In addition to the aforementioned info I would also check the timing again, that would not be fun to have problems with. Im sure you know as well as I do how the younger kids beat on their cars at " Da Grove."(I go to almost every Import Wars) So hopefully there isn't a deeper problem. Good luck!

PS the videos wouldnt work on my cpu, firewall issue Im sure. So I couldnt check them out. Hope there was no crucial evidence there!

 

[drifter7126]

has anyone figure out this problem...my car is doing the exact same thing..and seems to be running pig rich..you can just smell the fuel..but when you drive it..it'll clear up a bit because your burning all that off..any help would be great..thanks.

 

[Sumopower87]

This thread is probably dead but I'm gonna start it back up.

I recently rebuilt my Evo 3's motor. Started breaking it in following the "motoman method" car feels good, pulls hard, boost is @ 10psi, the compression ratio is 9:0:1. For two days the car was running fine. No rough idle or anything.

Drove the car friday evening and did a 3/4 throttle pull and a shift into 3rd (which I've been doing in 2nd, 3rd and 4th with no issues). Drove the car home normally and noticed it right away that the car felt different. Parked the car and the idle was rough just under 2k, anything over the car feels smooth.

So that lead me to get back on the research. So far the tranny and passenger mounts look fine but havent got to check the cross member mounts as yet. Had a friend come by and he said that it feels as if something is touching the chassis because you can feel the vibration in the steering wheel.

So I'll be getting dirty tonight to see what other things I can cancel out.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

this may help

 

[Sumopower87]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

this may help

Thanks. It wasn't so much idle surge but just more of a heavier vibration felt inside the car. My blance shafts are removed and all that good stuff.

Well I jacked the car up and took off the wheel, checked all bolts on the fluidampr pully and everything was still tight. I checked all the engine mounts and there all fine. Also I did a visual inspection of the spark plugs to cancel out if I dropped any cylinders, all were fine...no oil at all.

So while putting the plug wires back on I realized the DIPSICK! was popped out . Push the sucker back in and started the car. The harsh vibration went away. So why not...took it out for a stroll after it warmed up.

But NOWWWW ...I have a vibration in the clutch. Everytime I shift and the clutch engages it vibrates. Now thats another thing the car never used to do. Funny thing is it was hard to get into gear and now it goes right in with ease. The clutch is a Clutch Masters FX200 with the kevlar disc and the 2500lbs pressure plate. I have in a extention rod on the slave as well. Soooo now what .

 

[Sumopower87]

Ok guys. Turns out the passenger mount was loose. I tightened everything up and I'm still getting this vibration. A friend of mines gave me some spare mounts (transmission and passenger) I filled um with 3M 5200 marine sealant fast cure, so hopfully that should stiffen things up. I'll be changing the oil this weekend so I'll swap the mouns in then. If the problem continues...well it will have to .

Any pointers will be greatly appreciated.

 

[chadjoe]

Did you ever drop the subframe ?