valve train question

white94svt

white94svt

Member
#1
#1
i recently brought my car in for a dyno tune because the performance, even for stock felt inadequate. turns out my timing was off and they ended up squeezing some power out but the engine still has a funny sound. It kinda baffles under hard acceleration but still pulls hard. the shop told me because my car was sitting for a year and a half that the valves could be sticking or something like that? have you guys ever heard of that before? i dont doubt their diagnosis but im still confused. also is installing new valve springs hard? im happy with the gt40 heads until i have the funds to go ahead and do my rebuild with the trickflow setup i want. also its not fuel which i expected at first as well, could my distributor be causing the baffle? i know it was sticking when the did my chip tune so they had to do all the tuning set at 10 degrees. any feedback would be appreciated thanks
 
9

97modgt

Well-Known Member
#2
#2
I have never had that issue. My car sits for months at a time and loves to run anytime. Give her some marvel mystery oil and let it do work for a few days. If that doesn't take car of it then I would say pull a head if it really feels like a concern.
 
1

1BIGMOFO

Member Plus
#3
#3
I would recommend lucas engine oil treatment.. I had a valve sticking in a beater once and used that and its still running strong for the the guy that bought it from me :)
 
white94svt

white94svt

Member
#4
#4
yeah i'll try it out. the car starts right up and is ready to go everytime, which makes me happy, just has a weird exhaust note.

btw nice car man, i love how the wheels look
 
stanginthe11s

stanginthe11s

Well-Known Member
#9
#9
im confused about this word sticking, it seems the shop you go to uses that work for everything. either the valves open or they dont, if the valve doesnt open you will know it, if it gets stuck open you will know it and if it isnt closing all the way well then the car would run bad also. is it possible for a valve to not close all the way, sure but a good tuner or shop should be able to hear it just at idle The other thing is what was sticking in the dist? was the comp sticking and it couldnt alter the timing? or was the guy stuck and he couldnt turn the dist? just my opinion but if you have a guy tuning the car and he cant figure out a dist. etc. theres a problem. As for air fuel ratio, what was it at WOT ? whats the fuel curve and timing curve they did for your setup? If the car sat for over a year and never got started then the springs could be weak and you would have a motor that falls off around 4500+ rpm, what mods do you have to the engine exactly?
 
white94svt

white94svt

Member
#10
#10
the engine is stock, pretty much just o/r xpipe, coldair intake, and pulleys/ wires so i figured the car wouldnt be pulling too hard but its still a 5.0 and I expected a little more than my friends stock 94 gt. Well the shop told me that because the car was sitting for so long before I bought it, that can be the reason why the cars valve train dosent perform so well. He told me that the valve could be stuck in one position from that prolonged sitting period or something like that. would it be benefical just to replace the valve springs at this point? On my dyno sheet my peak power drops around 5100 rpms. air fuel was 13 across the board. yeah they told me after a quick test drive that the engine just felt a little tired:nono: so I was concerned. the rebuld is coming but i didnt expect it this soon. Then after the dyno/tune i was told my distributor was stuck and the car had to be tuned at 10 degrees and couldnt be advanced. I guess the gear was froze? then they gave me the fact that they felt my valve train was the issue. car runs and all, still breaks loose with stock gears, it just feels like its not breathing properly, sounds to me like a camaro with the raspy sound. dosent seem right:confused:
 
stanginthe11s

stanginthe11s

Well-Known Member
#11
#11
OK, well first id get a better shop as all they said isn't true id almost say not possible but anything is possible. first off the distributor cant get stuck, if the gear was stuck the car wouldn't start and theres nothing in those dist. to get stuck as the comp controls the timing curve and you just have to pull the spout out and turn the dist to set base. even if you had mechanical adv. you would just have to put a drop of wd on the weights. As for the valves, they're really basic and spring press. is what pulls the valves closed, if a valve was stuck in any one position you would know. If you bent a valve and it was stuck in the open position you would hear it blowing back into the intake just on cranking, if you got it stuck closed you would kill a lifter then open the valve lol or bend the pushrod. After a motor sits for a year or more in one position the springs start to get weak on the cylinders that were open along with the rust that may form on valve seats and you can lose power. Honestly if you are going to rebuild the motor then just do everything at the same time, its hard to diagnose on the internet and you dont have a before and after of the car so we dont know how it was before it sat around.
 
white94svt

white94svt

Member
#12
#12
i understand and thanks for the input. just gonna start the rebuild this year so i know where the motor stands exactly. i was just confused about the distributor myself. have you guys ever heard of a distributor making a squeeling noise before?
 
white94svt

white94svt

Member
#13
#13
well i was just revving the car in the driveway from the throttle body and noticed a strange sound coming from the stock throttle body. sounds almost like a metal vibration directly coming from the tb:confused: could this be the cause of my car not feeling so great? Nothing seems loose or visably wrong, Im lost as im still trying to learn the ins and outs of the 5.0. what are some symptoms of a bad tb? if i purchase a new one will i need to get my car retuned? i only plan on getting a bbk 70mm- any help would be appreciated guys thanks
 
You must log in or register to reply here.