Does a boost leak play havoc on base timing

[L2RTSiAWD]

My vaccum is reading wrong so I think I have a boost leak, This is furthered by the fact after warmed up the car idles like crap.

My question is does also wreak havoc on the ECU trying to keep base timing at 5-6 degrees, mine's jumping all over the place from 3-15.

 

[L2RTSiAWD]

Edit since I apparently can't spell the title of my own thread right...

 

[crankbender]

Originally posted by L2RTSiAWD
Edit since I apparently can't spell the title of my own thread right...

Are you only seeing the timing jump around at idle?

 

[L2RTSiAWD]

yes only at idle, everywhere else it's normal.

 

[crankbender]

Originally posted by L2RTSiAWD
yes only at idle, everywhere else it's normal.

If it is like a 1g (think it is) ground out your idle switch and see if it still does it (donno where the switch is on the 2g but it has to be on the TB).

 

[L2RTSiAWD]

Idle switch? not familiar with that part.

 

[crankbender]

There is a little switch that provides a ground for the ECU when you to to idle. Your switch may be not makind good continuity.

You can just ground it out and see if it stops. not sure where it is on a 2g but it has to be on the TB with a 1 wire clip and only get touched at idle.

 

[L2RTSiAWD]

I don't think the 2G's have one. I know what your talking about on 1G. but the 2G TB's don't have it.

 

[crankbender]

dizm.....

Do you know what the TPS is saying. Do you have any sort of idle surge?

 

[L2RTSiAWD]

No surge, I could test the TPS but I really think it's a boost leak since the vaccum on the boost gauge is reading lower than before.

I just want to know if a boost leak will mess with the timing. I could run a log at idle and post the results if that would help.

 

[crankbender]

Ground out the timing plug and see if it does it with the ECU not controlling timing. It probably won't.

If you have a big vacume leak you WILL idle high....nothing you can do about that pretty much.

What is the vacume saying?

 

[L2RTSiAWD]

I have an apex'i gauge.

The vacumm reads at 0.5 now and it used to read 1.5 lines below that(not sure of the actually number gauges in bar/kpa annoy me sometimes)

 

[crankbender]

1 bar is approximately 14.6 psi.

Have you compression tested the engine yet? could you have plugged your cat? how does the car run when not at idle and what does it do exactly at idle?

 

[L2RTSiAWD]

I haven't since I don't have a tester.

Not at idle the car runs like a champ.

At idle after warmed up it idles like I have a pair of race grind cams, real lumpy.

 

[crankbender]

unequipped mans way. First pull off the oil cap while it is idling and rev it up...does a lot of air come pouring out?

Second while it is idling pull the plug wires off one at a time and see if they all effect the engine the same.

I'm guessin you don't have a fuel pressure gauge either.

How are you checking timing? if you havn't yet check it with a light.

 

[L2RTSiAWD]

Ok I will try all of that.

I have a B&M gauge on the fuel filter.

You think I have a bad plug?

 

[L2RTSiAWD]

Originally posted by crankbender
unequipped mans way. First pull off the oil cap while it is idling and rev it up...does a lot of air come pouring out?

Nope.

Originally posted by crankbender
Second while it is idling pull the plug wires off one at a time and see if they all effect the engine the same.

Yes they do.

Originally posted by crankbender
I'm guessin you don't have a fuel pressure gauge either.

Yes. A B&M on the fuel filter and it reads 43psi

Originally posted by crankbender
How are you checking timing? if you havn't yet check it with a light.

I have been checking it with the logger, I will have to find a timing light and check it that way.

 

[u6t9]

hey, my timing also jumps all over hell when i'm idling. it will go from 3 to 17. and when it gets warmed up it idles bad and dies a lot too. i'm still working on it so if i find anything i will let you know.

 

[L2RTSiAWD]

Thanks,

My doesn't die at all **knocks on wood**

 

[crankbender]

what does the injector pulse on the logger say....does it jump around too?

 

[L2RTSiAWD]

Originally posted by crankbender
what does the injector pulse on the logger say....does it jump around too?

2g Loggers can't read IPW or duty cycle, only long term and short term fuel trims.

 

[crankbender]

yall 2g guys really got the short end of the stick...

 

[L2RTSiAWD]

Originally posted by crankbender
yall 2g guys really got the short end of the stick...

Ya I know, I need something high-end to view that stuff.

Friggin ODB-II

 

[crankbender]

look me up on yahoo some time and We will see if we can figure this out.

More than likely there is a reason your vacuume is so low and unfortunately it could be a bad seal in some intake valves. If the engine is healthy intake manifold pressure should directly coorespond to engine RPM...unless you are hitting idle fuel cut.

It might just be as simple as a bad gasket on your TB.

 

[L2RTSiAWD]

Originally posted by crankbender
look me up on yahoo some time and We will see if we can figure this out.

More than likely there is a reason your vacuume is so low and unfortunately it could be a bad seal in some intake valves. If the engine is healthy intake manifold pressure should directly coorespond to engine RPM...unless you are hitting idle fuel cut.

It might just be as simple as a bad gasket on your TB.

Thanks I will do that.