Hi, again I'm new here, found this site online, ordered a throttle body for my 2005 chevy suburban....
Really this all started a few years ago, like with my suburban, trying to improve gas mileage, which has been around 16 L per 100 km, no on board computer display though...
Recent work is as follows like my suburban: new magnaflow stainless y pipe, steel tail pipe and flow master muffler, muffler is much quieter than the magnaflow... oxygen sensors, plugs, wires, cleaned the throttle body with seafoam spray and seafoam tank additive..... plus other regular maintenance, none of this improved the mileage here either.....
So I decided to do some of these things to my astro van as well. Gapped the plugs at 70 thousandths, tried 80, but she hesitated a little, re routed the the pcv valve as suggested on this forum....
The result of doing these two things was an increase in gas consumption... talked to Ron and he said, number 1, there must be a vacuum leak, number 2, valves might be sticking..... so these i would have to address....
I removed the intake plenum, found the gasket was dead, an original, replaced it and the spider injectors, I had these parts, I rechecked all vacuum hoses... replaced all but one (they didn't appear bad, but just in case), installed the round vacuum reservoir, the heater control valve and another control valve, all are plugged into vacuum.. the hose off the control valve goes into the firewall to control heat, and air, not sure how to check inside, or if this valve solves anything... i also found that the plastic pipe that fits onto the throttle body was a little loose, can't get a replacement o ring, so wrapped throttle body with electrical tape, now fits a lot tighter, and hesitation off idle is at a minimum, almost gone.... so this was letting air into the throttle body.... will get some form a gasket or something to help here...
A friend who i told about the gadgetman groove, decided to get licenced since he has three vehicals, so we grooved my vans throttle body.... Did the ECU re learn.
Results are... van runs awesome, smoother, more powerful, quieter, it sounds great, when first started has a slight fuel smell from the exhaust, after warming up it is like a dryer vent... been driving it only a little, been on holidays so not in it as much as normal. Excited to see gas mileage after the next fill.....
