1G with 22 inHG vacuum at idle? 25 inHG deceleration?

[Devilsfutbol17]

From what I have searched for and found, it's not quite normal for a 1G to idle at 22 inHG, nor is it normal to go to 25 inHg upon deceleration. What could be wrong? What should I check for? Thanks

 

[crimsondragon]

That's pretty normal. Mine idles at 19-22 depending on the weather and 25 on deceleration.

 

[Devilsfutbol17]

From what I have looked up, the 2G are suppose to be like that, but not the 1G because they have different compression ratios of the pistons.

 

[Devilsfutbol17]

I'm getting 28 inHg vacuum upon deceleration. This is what happens when I let of the gas. 28 inHg vacuum....

Then this is idle, 22 inHg vacuum.

 

[CTP]

Compression has no effect on what vacuum the motor pulls. That's perfectly normal. Don't be sad that your motor is healthy.

What kind of gauge is that? The gauge could also be off. Regardless, it's nothing to worry about.

 

[Devilsfutbol17]

Also when I step on the gas, the gauge doesn't jump to 0, from what I have heard and seen, when you step on the gas you shouldn't see any vacuum. I still see vacuum while I'm stepping on the gas pedal. But I don't know if that is related to the fact that my 14b isn't at full boost of 12psi untill 4500 rpms. Its a Equus gauge, I just wanted one that would work. I have also swapped in my buddy's Autometer gauge and it had the same readings.

 

[GRAVEDIGGER]

Have you done a boost leak test? There is no reason that your 14b should reach a full boost of 12psi as late as 4500rpm unless there is boost leak somewhere. That thing should be spooled up and making full boost alot earlier.

 

[CTP]

Also when I step on the gas, the gauge doesn't jump to 0, from what I have heard and seen, when you step on the gas you shouldn't see any vacuum. I still see vacuum while I'm stepping on the gas pedal. But I don't know if that is related to the fact that my 14b isn't at full boost of 12psi untill 4500 rpms. Its a Equus gauge, I just wanted one that would work. I have also swapped in my buddy's Autometer gauge and it had the same readings.

What does it jump to? You have to hit the gas pretty hard for it to drop to zero.

What RPM is the motor idling at?

 

[Devilsfutbol17]

I did a boost leak test a while back and fixed my throttle body leaks. I got a new exhaust housing and a friend thinks the wastegate might be open a little bit so I need to do some adjustments, my wastegate actuator is adjustable.

When I step on the gas, it slowly starts to move up from 22 inHg vacuum to 0. Its not moving as fast as it does in other cars. It idles around 850 rpms.

 

[CTP]

Is the engine response normal and does the car drive normal? If you weren't looking at the gauge would you still be able to tell that something was abnormal?

What are you using for the gauge source and what else is on the line (if anything)?

 

[xveganxcowboyx]

Mine has always hit 0 if I floor it anywhere from maybe 2k on up.

Just out of curiosity, anyone that's running NT cams, what is your vacuum?

 

[Devilsfutbol17]

Well this is the only DSM that I have drove so i don't really know, but I had a friend that has one and he said when he drove my car it feels like a non-turbo until 4500 rpms. He also told me that the vacuum should move quicker to 0 than it does. I am using the fuel pressure solenoid to tap my boost gauge.

 

[Spades]

The brand and quality of the gauge will make a difference on how fast it gets to zero. I had an Autometer and switched to VDO boost gauge and noticed the same slow response. Never heard of Equus brand gauges but it may be the same case

 

[Devilsfutbol17]

Ok I will look into getting a new boost gauge.

 

[CTP]

Well this is the only DSM that I have drove so i don't really know, but I had a friend that has one and he said when he drove my car it feels like a non-turbo until 4500 rpms. He also told me that the vacuum should move quicker to 0 than it does. I am using the fuel pressure solenoid to tap my boost gauge.

Try sourcing it somewhere else just for the hell of it.

Does the motor pick RPM slowly when you're free reving it or is the gauge the only thing that's lagging?

 

[NB4G63T]

Ok I will look into getting a new boost gauge.

Check and make sure your line from the engine to gauge is not kinked. Mine would kink when i slid the gauge into the pod, the line would bunch up behind the gauge. As this made the gauge very slow to respond.

 

[Devilsfutbol17]

The motor revs just fine, it's not slow that I can tell. I didn't really think to check for kinks in the line, that could be the case.