Rough Idle after new headgasket install please help

[vgknightcc]

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I have 90 turbo and i just recently pulled the head to replace the valve seals and I put everything back together and deleted the vacuum lines from the throttle body by looping them... i looped the egr and unplugd the solenoids by the brake booster... After i connected everything back together it would idle like my timing was off... well i checked it a few times and it seems to be correct all the marks line up... i did notice the exhaust dow looks abit to the right of 12 or maybe it is the lean the motor has i am not sure... but i have ran it and it sounds like a slight miss... It has new plugs wires and i even switched ptu same thing.... its getting fire from all 4... it also drives smooth and revvs perfect just ugly idle... oh and i ended up pulling the turbo because it was the reason i was smoking not my valve seals.... i am getting the fp 3052 and would really like to square this before i receive it....


here is the exhaust cam timed....

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here is the 3 and 9 oclock lined up

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[donmagicjuan]

Get a straightedge and verify the marks fall on a straight line through the center of the cam gear bolts. You can't eyeball this, and doing it right will tell you for sure if your timing is really off.

 

[vgknightcc]

Yeah the thing is i do this all the time and i always get it.....the 2nd time... and well unless i have a vacuum leak or something??? I did replace the intake gasket no leaks there i sprayd it with starter fluid to see if it had leaks... none... same with both throttle body gaskets.... so hmmm.... I dont know....i have a buddy of mine come and check the timing and it was dead on so any other things i should be looking for??? I have never had this problem with any of my dsm's and so i was thinking maybe it was the valve seals but it cant be....

 

[donmagicjuan]

Well, you could always do a boost leak test to rule out the stem seals, and a compression test to rule out the valve seats.

 

[donmagicjuan]

I went back and reread what you said you did to the EGR valve. I'm not exactly sure what you meant, and 90s are a little different, but if you apply vacuum to the EGR valve on a 2G at idle, it will run like a bag of ass.

 

[vgknightcc]

Well basically there are 2 vac lines on top of tb and 2 on the side.... i just loopd the 2 top, and loopd the 2 side... and on the egr there is 2 lines i just loopd those to each other also.... i was told that would work....maybe not though....

 

[vgknightcc]

maybe i need to leave the line open on the egr then....

 

[donmagicjuan]

I guess I'm just curious why you would do this. Did you install an EGR blockoff plate? I can't imagine accomplishing anything by messing with the vacuum lines unless you have.

 

[vgknightcc]

Well basically everybody i know who owns one has just pulled all the vac lines off the tb and the egr so i did as everyone else did.... and look were i am at.... i usually do my from my gut but this time i figured what the heck....no egr plate.... but nobody i know has one either....i guess i need to look deeper into the egr that might be the problem....

 

[chanley talon]

Hey i think your egr is leaking under boost if not capped off also you said you unhooked all your vaccumm lines on the right side of the motor Surley you didnt unhook the line that runs to your fuel pressure regulator .. Did you?

 

[chanley talon]

Also i had a simular problem after my rebuild and come to find out i was leaking air past my injectoer o rings where it bolts to the head.

 

[vgknightcc]

yeah i have had that before but i sprayd starter fluid around all the would be leaky areas and nothing.... so i ruled that out

 

[vgknightcc]

I unhookd the 4 lines that run to the solenoids to the the plate behind the intake then to the 4 lines on the throttle body.... i hooked the fpr vac to the nipple on the intake next to the coil....

 

[donmagicjuan]

Well basically everybody i know who owns one has just pulled all the vac lines off the tb and the egr so i did as everyone else did.... and look were i am at.... i usually do my from my gut but this time i figured what the heck....no egr plate.... but nobody i know has one either....i guess i need to look deeper into the egr that might be the problem....

Wait, so you pulled the vacuum line off the top of the throttle body completely? Again, I'm not terribly familiar with the 90 TB, but if you have a port that is allowing air to enter your intake downstream of the TB, then that would definitely explain a crappy idle. My suggestion would be to hook everything back up the way it was, and if you want to run without an EGR valve, check out the vfaq page:

http://www.vfaq.com/mods/wayback/BradBauer/engine/egr.html

 

[vgknightcc]

Okay i looped them like this....i am using a 91 throttle body pic ### i dont have a 90 pic and i am at work....so bear with me.... the blue lines i loopd togther the red lines i looped together.... but on my tb the red lines are acutally on the side of the tb.... but they arent open... the are loopd shut.... so no leaks....

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[chanley talon]

Ok it is a fact that your egr will blow boost out if not bloked off on your car . Also you need good vaccumm on you fpr . But still these wouldnt give you a horrible crappie idle.
What about you blow off vavle line is it hooked up ? Also you have a small nipple right above you coil pack see if that is hooked up . Your pvc vavle shoud also be hooked up to the intake . You might check to see if your intake running to the turbo is all the way on as well.

 

[vgknightcc]

Okay i have the nipple on the intake going to the fpr and it has a t to goto the boost gauge line... The bov has is connected at the other nipple on the intake close to the tb.... and well here are some pix to help visual.....

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FPR and Gauge to intake by coil....

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Throttle body looped....

I didnt get a pic of the egr ### it was hard to get camera in there but it just has a hose looped like on the tb.....

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and i am not sure if these matter the 2 vac nipples on the thermo housing....


I put a boost leak tester at the tb elbow and i could hear air escaping by the pcv so i pulled the hose and it had a slit it.... so i replaced it put clamps and now i just hear air when i pressurize it.... but i dont know if it is just the air moving through intake it doesnt sound like it is leaking anymore is that normal??? Yes the intake was properly on the turbo....

 

[donmagicjuan]

Ok, this is where someone else will have to come in, because I'm not very familiar with the 90 throttle body. If you don't hear from anyone, however, I would default to the original configuration to at least see if that cures your problem. Then you can try the things you've done one by one to see which one is the culprit.

I do have two other questions, though:

1) Why have you bypassed your fuel pressure solenoid? I'm not an expert on its purpose, but I know that it remains shut while the car is cold, which raises the fuel pressure until the car is in normal closed loop operation. I can't think of any performance gain associated with bypassing it.

2) Where is your coolant overflow bottle? Did you just remove the line for the sake of the picture? If that's the case, and you're referring to some other "vacuum nipple", I'm not seeing it.

 

[vgknightcc]

I pulled the line on the overflow so you could see the vac nipples. they are between the radiator hose and the coolant return for the turbo.... I bypassed that line because everybody i know has it that way and i was just trying to clean up the engine compartment. I wanted to get rid of un needed hoses wires u know...... so the fps is needed then???

 

[vgknightcc]

Okay i figured it out.... and i have to say i feel really dumb.... i usually set the gap on my plugs with my feeler gauge... and well i bought a new one and didnt realize it was in mm not inches... so i gapd plugs @ .028mm not .028in... problem solved....just in time... i get my fp 3052 tomorrow....and i think it will make pretty decent power....

 

[donmagicjuan]

I'm glad you found the problem. I was starting to become thoroughly confused. Good luck with your turbo install!

 

[vgknightcc]

http://www.corpusracing.com/showthread.php?t=837

here is the thread with my new fp 3052 installed it is awesome spools at just under 2500rpm its a strange new love

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