Warm LT1 issues.

[QuickTop]

. I've noticed lately that once my car is good and warmed up, a few things start to happen. It seems as if my power has gone down drastically. When in neutral/ coasting the idle is inconsistent almost like a miss. But I think that's related to my fuel pump going out. And lastly my oil pressure at idle is pretty low. And when driving it never goes above 40 PSI, unlike when it's cold the more RPM the more the power/oil pressure. Like it should be..

Anyone have any ideas ?

[JoeliusZ28]

40 PSI oil pressure at warm cruise is perfectly normal on an LT1. Youll peak maybe 50 at WOT right before redline.

You say your idle is inconsistent with a miss.... is the miss consistent?

[QuickTop]

I want to say the miss is consistent. Ill pay more attention tomorrow.

[SOPES]

throttle sensor ? MAF ?

[Sic96]

You're going to lose some power/pull once it's all warmed up. I do, as well as everyone else. The cooler the engine, the better it runs. That's why when it's 65f out, the car will pull like no other, but when it's 90 out, you almost seem disappointed. There shouldn't be a "major" difference in power, but a noticeable one at the least. If we're talking like 50hp or so, then there are other issues there.
As far as oil pressure, mine reads way higher than 40.. or even 50. It says around 80psi, but maybe my gauge is bad lol. Inconsistent idles; always start with vacuum lines/leaks and work your way from there.

[popo8]

40 PSI oil pressure at warm cruise is perfectly normal on an LT1. Youll peak maybe 50 at WOT right before redline.

You say your idle is inconsistent with a miss.... is the miss consistent?

According to GM specs...the lt1 is functioning properly right down to an idle of 7lbs oil pressure.

The increase 10 lbs for every 1 k of rpms

Co-Owner/Admin @ LTXtech.com

[hoogiesngrinderz]

According to GM specs...the lt1 is functioning properly right down to an idle of 7lbs oil pressure.

The increase 10 lbs for every 1 k of rpms

Co-Owner/Admin @ LTXtech.com

GM spec.

But would you be comfortable with your LT1 running at 7 psi?

I don't have a vehicle that idles less than 40...at temp. I get a funny feeling with anything under 20, the last one I had that did left me with a bunch of glitter and a big bill.

[popo8]

GM spec.

But would you be comfortable with your LT1 running at 7 psi?

I don't have a vehicle that idles less than 40...at temp. I get a funny feeling with anything under 20, the last one I had that did left me with a bunch of glitter and a big bill.

At idle...absolutley...and i have when it was stock.

Specs are designated for a reason. As long as it increases with rpm... No harm

Co-Owner/Admin @ LTXtech.com

[hoogiesngrinderz]

At idle...absolutley...and i have when it was stock.

Specs are designated for a reason. As long as it increases with rpm... No harm

Co-Owner/Admin @ LTXtech.com

LT1'ers are a weird bunch Kidding!
I feel that 7psi is too low, but if you're ok with it and are getting ~50psi in the upper RPM's then I wouldn't worry much.


Take look at everything that affects the fueling. MAP, MAF, IAT, CTS. Make sure the TPS sweeps, check o2's

[QuickTop]

I payed more attention to to the idle and it doesn't seem to be a miss at all. Just at random times it will drop way down to < 500 for a second and shoot right back to 850 and be fine. But this is my warm oil pressure gauge. ImageUploadedByTapatalk1372867864.455433.jpg

My 02s are less than a year old. As well as plugs and wires. Ill look into my IAT and TPS. What's the best way to test a TPS?

[SOPES]

Before even doing that, manually clean out the throttle body of all carbon build up

[hoogiesngrinderz]

True, I've seen those IAC passageways get pretty nasty!

[SOPES]

Also about the oil pressure, pull the oil pressure sensor out and make sure it isnt covered in sludge and giving a false reading

[9302z28SS]

Change the fuel pump. Mine was doing the same thing. Changed the pump
And it was back to a happy powerful lt1.