Seems to be running on 5 cylinders and no vacuum to brakes..

[RobsIron]

Went for a ride finally after upgrading the rearend and adding drag radials. Man, what a difference those tires make. Its a absolute beast! Got on it just a little a few times..no all out. About a mile from the house while just cruising it sounded like a cylinder drop off suddenly and started running a little rough. Brakes got hard too. Made it home no problem. Temp and oil pressure remained the same. No smoke anywhere. It sounded really good missing like that..heheh. Car has only 1400 miles since build, but is getting close to 15 years old. What do you guys think it may be?

 

[turboclam]

Try and verify which cylinder is down. You can use a temp gun to help.

Injector/ignition related?

If that checks out then look at valve spring.

 

[jasjamz]

Check to see if all the plug wires are on. Make sure all the injectors are plugged in.
At idle, unplug an injector plug and see if it changes the tone. Do that until you find the one that has little to no change.
then you have found your problem cylinder.

 

[jasjamz]

DP

 

[69RSCLONE]

Broken valve spring will kill the engine vacuum and power brakes if converted to vacuum assist. If you have a vacuum gauge, check for rapid flutter. That will point to valve spring. Then check to see which cylinder and go from there.

 

[RobsIron]

I did just change my plugs wires to a 10mm a few weeks ago. I took this pic today.

I guess losing a cylinder would affect the vacuum on the brakes.

I hope that's all it is..

 

[RobsIron]

First thing I thought was plug wires. then coil pack or cam sensor. Hope its not a valve spring, but I'll do what I gotta do. Can't wait to drive it again. Its like a whole new toy that's been in my garage for 11 years.

 

[SCOOBY DOO]

Rob...you may have lost a coil. Put a new coil pack on it. Had that happen making a run at the track. Got back to the trailer and pulled the coil pack...and one of the tabs had broke off...killing two cylinders.

Brad

 

[Turbotre]

Sounds like a vacuum line popped off under boost.
I see you have your brake vacuum hose tee-ed in with the PCV valve.I'd check in that area first.

 

[RobsIron]

Installed a new shifter today. Tried to diagnose the miss too. The heat gun worked great! #5 cylinder not working. Checked all the vacuum hoses, changed the plug wire and swapped injectors on harness, but still has a miss. Had to finish shifter, so will work more on it this week. Pull plug, hook up vacuum gauge and check harness at computer next try. If its the coil pack who sells the best one? Do you they make one with more output?

Thanks for all the input. Big help so far.

 

[SCOOBY DOO]

NOS4GN. I run one from them...and race the car every weekend. Time is in my sig. Stock stuff works just fine.

 

[RobsIron]

Did compression test on all cylinders tonight. All 125ish. #5 was 125 on first attempt. I was happy. 2nd attempt 0. Not so happy. 3rd 105. 4th 0. 5th 105. 6th 0. So, I'm thinking a sticky valve. Pull of valve cover and there is no visible damage. Spin motor over and the intake and exhaust moved normally. So, cam looks to be ok.

Valve spring? If the compression ring was damaged would it have given a 125 reading?

What the hell?

 

[RobsIron]

Spark plug had some carbon on it. Wonder if a valve has some carbon build up or the spring is weak or broke. Only 1400 miles on it, but the build is 15 years old...

 

[turboclam]

Do your springs have inner springs? Take a real close look and make sure that you don't have a broken coil. Roller cam?

 

[RobsIron]

Do your springs have inner springs? Take a real close look and make sure that you don't have a broken coil. Roller cam?

I was trying to see the inners, but can't. Powerbooster in the way.

Comp cam flat tappet 218.

The compression test was done cold. I just wanted to see if #5 was acting up. Warm would have delivered better #'s, but don't think it would have made a difference on diagnosing #5. I could be wrong.

 

[RobsIron]

Broken valve spring will kill the engine vacuum and power brakes if converted to vacuum assist. If you have a vacuum gauge, check for rapid flutter. That will point to valve spring. Then check to see which cylinder and go from there.

Ding ding ding ding! We have a winner! I pushed on all the rockers by hand and #5 exhaust is mushy. Here is a pic. They have orange stripes. Here is a pic. Anyone know what kind they are or can recommend a real good set? Cam is a Comp 218 485 lift.

Thank you all for the help!

 

[RobsIron]

Try and verify which cylinder is down. You can use a temp gun to help.

Injector/ignition related?

If that checks out then look at valve spring.

You said it first TC!

 

[turboclam]

Great that you found it! That won't be a bad job since you don't have a heater box.

I first saw your car in 1999 in Ohio. Love that car.

 

[RobsIron]

Great that you found it! That won't be a bad job since you don't have a heater box.

I first saw your car in 1999 in Ohio. Love that car.

Thanks man. I just spent around $3k on it and it starts breaking! Ha! Never given me any trouble until I started 'upgrading" it. Should have left it alone.