nicholasbartleet

OK Slows2k,

So the vacuum Tester arrived today. I hooked it up to the brake servo vac line, and i think its showing a problem.

On ignition and first idle, it flicks up to 20 insHG which seems ok. On throttle blip it moves up to 25 insHG but doest descend back down to 20 insHG. The idle then sits at 25 insHg even when the car is turned off, it remains at this pressure, even if the throttle butterfly is opened.

When you unplug the Gauge there is the loud sound of air escaping (psst) and the gauge drops down to 0.

If you leave the guage plugged in and turn the engine off and then back on again, the idle flicks up to 24insHg instead of 20 which is way too much idle pressure isn't it?

It seems like the pressure is building up too high and getting locked in. Any ideas?

Slows2k

Does the vacuum reading drop below 20inHg when the idle speed in going up/down?

nicholasbartleet

The idle speed didn't fluctuate today and no clicking.

I will leave it plugged in and try tomorrow. Could it be that because i released the intake manifold pressure this morning by fitting the gauge that it started ok?

nicholasbartleet

Right Right Right!!!

So i figured out that the hose for the brake servo was somehow trapping the vaccum air in it (maybe this is a feature i don't know) so i went straight into the inlet manifold with a fresh hose and totally different results:


Measurement is in/Hg
20 Start Idle
0 Momentary when Blipped throttle
29 Rises to when Blipped Throttle
18 Drops down to after Blipped throttle and car shudder (almost stalls)
22 Raises up to after car shudders (almost stalls)

I have no idea if this means anything, but i will keep testing and hopefully get some results when the morning start problem is occurring.

kchandra

1) is your coolant full?
2) have you burped the system quite a few time?

sorry for n00b questions, but I had idle surge on a civic which was a coolant issue finally...

And I will add, I replaced 2 ISC's on the damn thing and I finally sold it so pissed at it. (lots of other issues as well). Lo and behold, new buyers throws in an ISC and it fixed it...wtf.

nicholasbartleet

Well i did have a coolant/fan problem and changed the stat and fan switch (which fixed the fan problem), which i thought had fixed the cold start idle issue, but low and behold the problem returned a week later.

Maybe there is still air in the system. I will look into that tomorrow too, thanks. Its good to know that this can cause a similar problem.

kchandra

Well. it could be air OR you have a coolant leak at the water pump or something that is making your coolant level drop and cause it -leaks at water pumps are hard to diagnose coz the coolant evaporates....I am no master mechanic by any means, but I am sharing what I Know and have dealt with.....

nicholasbartleet

Hey Slows2k,

So i tested it this morning, and i did get some engine clicking and a little fluttering in the revs today although not as bad as it can be.

The vac pressure was LOW at 17in/Hg

When revved, it dropped to 0 then went to 15 and hesitated before flicking up to 25.

As the car warmed up, and the air pump stopped cycling, the vac pressure went up to 20 and the vac pressure/engine responded more healthily.

Any ideas?

nicholasbartleet

So, i tested it again today on cold start and the engine was clicking and surging a little. The vac pressure was reading consistently low at 16in/Hg. The air pump was cutting in and out repeatedly.

On throttle blip the vac pressure would drop to 0 and return to 16 instead of dropping before flicking up into the mid 20's as it should.

Soon after the air pump cut out for the last time, the vac pressure went up to 20in/HG and the car ran sweetly. On throttle blip the car vac pressure would drop to 0 and then up to 25.

It would seem that this problem only happens in the morning because that is when the air pump cuts in.

So my question is what part of the secondary air system could cause vac pressure to drop?

Maybe I should i just get a air pump delete kit and remove the whole thing?

Any thought would be really appreciated.

Thanks

nicholasbartleet

Update:

So the bad news is that i blocked off the secondary air injection solenoid with a block off plate. Closed up the vaccum / air lines to it and then removed the fuse from the air injection system effectively removing it to test if it stopped my cars 'morning sickness'.

I tested it this morning and i still have the clicking/surging. The vac pressure is still reading low at 16 in/Hg untill it warms up and then it moves to 20in/Hg and runs fine.

What could be causing the vacuum pressure to be low only in the morning? Any ideas? I'm pulling my hair out.