Last Sunday. I got some header wrap and wrapped the intake of my truck to keep the radiator heat out of the intake.

I hop in today, driving it for the first time since Sunday, and the idle is REALLY lopey. I'm talking old muscle car big block lopey. I also noticed that the idle is lower and the truck is quieter than usual. It also has more pull. (No complaints about the extra pull) It will pull harder through all the gears, and I can really notice when it "hits its power band". This is extremely noticeable as I have 4.10s and 33x12.50s. I have not done anything else to the engine other than hook up an EGR vacuum line that I noticed had slipped off, but that was over a week ago, before the wrap, with no differences. The engine also lopes so bad (good? I kind of like it) at idle that the truck will get a little bit of a shake and vibration as it turns over and over. It will not die though, it will just idle really low.

Truck is an '89 Pickup. 22R/e, W56, All cylinders are firing, the engine was tuned up (new plugs, wires, cap, rotor, fuel filter, air filter, oil change, and PCV valve) over the last year. There are no codes being thrown either. I don't know that this is a bad thing, I certainly can't complain about the nice lope and power, but is there any idea as to what is causing this? It didn't do this before I wrapped the intake. Should I be concerned? Is the intake wrap what is making it do this? I really didn't think wrapping the intake would have such a HUGE effect. If it is and this is no cause for concern, then that is by far the best bang for the buck mod I have ever done to my truck!

By the way, here are some pictures of my truck with the wrapped intake:



Thanks in advance!

 

 

the only concern would be that oil pressure would be extremely low if the idle is way down. watch your gauge.
reset your idle and see if the lope goes away.
did you accidently hit anything taking it in or out? i can't imagine the insulation value of the wrap makes much difference on start up. once hot, sure the benefits should be felt to some degree.

 

could check with 4xJedi, he did the same:
https://www.yotatech.com/forums/f116...ir-box-124063/
see if he had the same problem.

 

Might want to test the throttle position sensor, if the IDL-E2 adjustment is off there, your idle can be too low:
- http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

And you might want to check the EGR connections and valve, maybe something is plumber wrong. EGR opening too soon or sticking open can cause a low, irregular idle.

 

TPS is just fine.

EGR is plumbed correctly. Thanks for the links!

I don't think you can test EGR valves

I might try unplugging that vacuum line that was unhooked for so long and see if this problem goes away. If it does, I'd assume it has to do with the EGR system.

The idle isn't excessively low and my truck is a DLX so I don't have any kind of oil pressure gauge. I might invest in one soon though, as well as a tach. I've really been wanting a tach. I am guessing the idle is around 600rpms. Is this low enough to cause an oiling issue? The temp gauge stays cool, so I know it is not overheating, but I don't want any galling!

Also, the first day I drove it, the temperature was down as well. Normally it has been in the mid 80s by morning and very humid as we've had a lot of rain. The first day I drove it after the intake wrap, it was about 60s in the morning with maybe 30% humidity. Much different conditions.

 

EGR can be tested, procedure is in the Factory Service Manual. One trick is to tap on the valve body and see if the idle smooths out. If so, the valve is sticking open.

Also, try turning up the idle speed, large screw atop the throttle body.

 

Well, the problem seems to be intermittent. So I think the EGR valve might be going. I'm going to wait until it does it again so I can tap on the valve body and make sure, but I just tried a second ago and the truck idles normally.