Car 1988 vert with a t2 motor stock
So im wondering if pulling vacuum at idle is worth anything. Ive searched and theres no specs and cant find anything about anyone else doing it. I was told about 16in at idle is what your looking for so i have about 10-11 at idle and it only increase to 14-15 at high rpm. Im thinking a vacuum leak but ive searched and searched, and think ive gotten everything. But anyway the car seems to run alright but i shakes really really bad when driving or even just idling. i was hooking up the test light to check timing and i didnt get any light from the trailing in the front. About 2 weeks ago i set timing with the test light and i worked fine. the trailing plug has spark but for some reason the coil isnt firing. Could this be the problem for the shaking. Or will it run alright just off of one plug?

 

ok so the car shakes at idle real bad. Played with the timing and what was strange was i could not get the trailing and prim to match up. If i set one it throughs the other off? does that mean anything to anyone, It feels alot like theres a misfire. It clears up at 1500 rpm the motor sounds good and the shaking is gone. Then at 2000rpm and up shaking is back. The motor was bought used from what was said to be a rear accident in a t2. It has good compression all around.

 

check your TPS for the bad idle stuff

a shaking motor at idle could be a bad motor mount or tranny mount. These could be two unrelated problems.

 

I have adjusted the tps. I really wish i had an oscilloscope to test the tps. I also suspected the motor mounts, they probably do need to be replaced. Anybody know of some good motor mounts. Ill replace those anyway, but i think its more of a misfire shake. the motor just doesnt seem to be running right

 

Ok so i have been thinking about where a leak could be because i have checked and checked when i blocked off the air control valve i dont think i left the scroll scheck valve of whatever it is in. Does anyone know if this will cause a leak. I believe i remember someone saying that you need to have that installed if you block off the air control valve, but sense its blocked off is it need? any help is greatly appreciated. thanks guys

 

As of right now im hoping its a motor mount problem but it doesnt really shake at 1500 rpm and the engine doesnt pull good vacuum doesnt really sound right either whihc makes me look away from the motor mounts. hopefully the motor is not out of balance cause that would suck big time. Im also thinking maybe the low vacuum could be cause by a problem with the turbo? Anyone have spec on vacuum at idle and off idle, should i really be worried about vacuum? pleasee.........thanks guys

 

Should be pulling 16-20 inches at idle if everything is tight.

 

Do you have a manual?
Sounds like misfiring,
Check grounds, plugs, wires.

Is leading plugs in proper locations (bottom)
is trailing plugs in proper location(top)

is the t1 and l1 plugs in the front rotor and visaversa?

In a turbo car, any throttle response gives boost.

Also, Check proper fuel pressure and make sure at least ur injectors are clicking.

It may help to record the sound ur car makes, then posting it.

 

manual Na trans. I also believe its a misfire. The leading and trailing plugs are all hooked up correctly with t1 and l1 going to the front rotor and t2 and l2 to the rear. Fuel pressure is 37psi drops to about 35 with engine running. Injectors are clicking, fuel pump volume is also good. I wish i could record but the car is 5 hours away and i only get to play with her once and a while either this weekend or next ill be trying to go work on her and ill try to post a video.

 

if youre worried about vacuum leaks check with an air compressor (do a search). i dont think the check valve you were talking about will have any effect on it, its blocked off. did you use any gasket sealers when u put the blockoff plate on?

 

Yes high temp rtv sealant. I dont have a air compressor but this weekend coming up im going out there and ill update with some fresh info

 

So once we figure out how to get the videos on here ill have some visuall. But i tested the motor mount and they seem good. 1900 rpm and up though still shakes the car. Vacuum at idle is 12in when raised to about 20000rpm its about 14in. Took the car to red line someone said that you should to clean the carbon out probably better under a load but maybe it will help. Now the engine jumps around vacuum goes from around 10 and then up above15 i have the video. I think a seal may be stuck because after i took it to red line it pulled like 15in at idle. or maybe it was all thge oil from the throttle being open helped seal.. Anyone im thining about checking the grounds and maybe some ATF into the spark plugs see if it is a sealing problem. Compression was about 100 all around. I also have a emanage ultimate just sitting around so i might install it so i can see what the ecu is getting from the sensors. Ill have the vids up asap any ideas helps thanks so much guys

 

Ok so i have the video posted now but for some reason the copmuter hats me and didnt upload it with sound and made my hands blue.
<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/8vAadZoueSs"> </param> <embed src="http://www.youtube.com/v/8vAadZoueSs" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

 

alright never mind that didnt work. let me try something else.

 

Well i got this problem fixed just to run into another. The cause of the shaking was a misfire. The cause of the misfire was who ever had the motor before chopped up the harness. The car threw a code for a ECT me being a stupid ordered and a new ECT before checking the wiring. Guess i was lazy anyway new ECT didnt fix problem so check the wiring and battery voltage at ECT....hmmmmm thats strange doesnt it work off a refernece. So i took off the intake manifold for the millionth time. and dug deep to find out that the power for the ECT was going to the front prim injector. And the front prim injector had the ECT 5vref.... ooo that may cause the misfire. So now i start the car and its hards to start then if it does start it dies if i take my foot off the gas. From on problem to the next, by the time this thing is fixed i will konw this car inside and out and take off that intake manifold blind folded. O checked the codes no ECT code but there is a fail-safe mode code for the airflow meter. So back at it tomorrow fingers and toes crossed maybe this thing will run GREAT.well eventually