valve guides?

[shmed]

is there a way to tell if i need to replace the guides in my heads without removing them?

reason i ask is when the gn is running the vacuum gauge goes between 14 and 10 continously. and holds steady at a higher rpm llike 2000.
while the gauge bounces around the engine also surges kinda at the same time. maybe related?

im curently running stock ecm stock inj's stock chip fuel at 42line off.
new ac 43 plugs coil pack and module tested with caspers tester thing.
magnecore 10mm wires

any help appreciated this is driving me nuts..
tia
Dave

 

[Topjimmy]

I'd think it would be more hassle than it's worth to accurately check them on the engine. Since you note the surge, I'd look for a vacuum leak first then determine if the cam is healthy. How many miles on the heads? How's the compression? Warm engine, throttle open readings?

 

[shmed]

well compression test results are #1-142
2-142
3-140
4-140
5-135
6- 152
this was taken with engine warm and throttle fully open,

i double checked every vacuum line on the car an applied vacuum with the miti mite vacuum tester all is good there.

the age of the heads are unknown bought em used, but had them pressure checked and a 3 angle valve job done then resurfaced to be sure of stragihtness,
any ideas?
thanks

 

[VadersV6]

Do you burn alot of oil? If not, its not the guides. They would have to be really bad for your vacuum gauge to bounce. Do you have alot of valvetrain noise? A bouncing vacuum gauge is usually a sign of a cam lobe or 2 going flat, or a cam being installed wrong. Or, that you've lost some cam gear teeth and the timing has slipped. Do you still have the stock timing gear in it?

 

[shmed]

lets see no oil loss or visable smoke.
theres some noise i thought it was cam sensor though??
im running a trw steel timing chain and gear set up.
its about 3-4 years old now and the engine was popping very hard at the track last time out.

 

[shmed]

tonite i pulled the valve covers off and spun the motor over while i watched the rockers they all seemed fairly close in lift..

changed the wires to a set of RA wires i had and it actually seemed to smooth out a bit, vacuum was still going up and downt though.

ii then unplugged the iac motor ( on a whim) and the vacuum problem smoothed out even more to the point where it was only going up and down maybe 2" like from 15 -13, getting closer..

any ideas now?

 

[TurboJim]

Is it a rhythmic flutter on the gauge needle? If so there is a pumping prob with the engine. Compression may be good, but one cyl isnt contributing 100%. Weak valve spring or sometihing to that effect (valve clearance, burned valve, wiped cam etc). If the gauge just moves arounf and theres nothing rhythmic to it, its probable normal. Youre just seeing the ECM throttle up and down the engine trying to control isle speef.

 

[VadersV6]

Maybe the gauge isnt in great shape. Maybe the vacuum line going to it is kinking up, or has a pinhole. Where is the vacuum line connected? Are the idle rpm's bouncing around?