ATXBreeze Posted December 12, 2023 Share Posted December 12, 2023 (edited) Hi Folks! My 1989 Micro Sprit (Toyota Truck 3.0L 3VZ-E) starts right up every time, but after the engine drops to idle, it begins to huff and puff as seen in the video, especially highlighted in the shot of the muffler. While test driving, it accelerates smoothly and with plenty of power. But when I get to a stop, it begins the rough idle I described, and “huffing and puffing” (video). And although I’m applying the brakes, it wants to move forward, even occasionally inching forward. When cruising, if I take my foot off the accelerator, the engine will “miss”, but as soon as I accelerate, it goes away. Stuff I have done so far: Changed the throttle position sensor. Did a smoke test, but not a very good one (blew cigar smoke into the hose that goes into brake booster). Changed air filter. Rotor, distributor cap, wires and plugs are all fairly new. Timed correctly. MPG same as it ever was. Symptoms similar to what MaineJed posted on this thread No misfire. No check engine light. Should I swap out the EGR next? Perform a better smoke test? Could it be the fuel filter? Or a failing fuel pump, or something having to do with the fuel system? All suggestions are welcome, and thank you! IMG_8086.MOV Edited December 12, 2023 by ATXBreeze added material Quote Link to comment Share on other sites More sharing options...
MaineJed Posted December 12, 2023 Share Posted December 12, 2023 Its not a EGR, it would be worse than that. I would say something in the fuel delivery system or not getting enough air somewhere. Never heard of a smoke test the way your doing it 😆 Quote Link to comment Share on other sites More sharing options...
Toycollector47 Posted December 12, 2023 Share Posted December 12, 2023 Your comment about the lack of breaking power at a stop immediately makes me want to point my finger at that vacuum system. Possibly even a bad booster itself. Im not sure what cigar smoke might tell you, but little spritz of starter fluid here and there around suspect vacuum lines can help narrow down leaks. Once you hit a leak with the extra fuel there will be an almost immediate change in engine idle either way smooth or worse. Quote Link to comment Share on other sites More sharing options...
ATXBreeze Posted December 12, 2023 Author Share Posted December 12, 2023 (edited) The spritz of "starter fluid" on all the vacuum lines was the very first test I tried, but it produced no noticeable difference in the engine to indicate a leak a vacuum hose leak 🙁 The crazy smoke test I did with a cigar I saw someone do it on, where else, YouTube! A faulty bad booster had crossed my mind regarding my stopping issue. But would a bad booster cause the engine to run lousy and "huff and puff" like in my posted video? Also, the power steering component leaks oil. I know the power steering is connected to the vacuum system. It's never been great a producing "power steering" after I top off, (turning the steering wheel somewhat smoothly) but eventually provides no help and the wheel becomes hard to turn, but not impossible. BTW, I've tried to take it to a shop, but nobody will work on a 1989 Toyota truck! Thank You, and please keep the suggestions coming! 😀 Edited December 12, 2023 by ATXBreeze added comment on power steering. Quote Link to comment Share on other sites More sharing options...
Ctgriffi Posted December 13, 2023 Share Posted December 13, 2023 Block off (or clamp tightly) the brake booster hose for testing purposes, see what that does to idle. Bad vacuum leaks can definitely mess with the idle. If that ^ turns out to be a red herring, might look at the fuel delivery issue that was mentioned already: check pressure at the rail and look for ~40psi. Running a few bottles of injector cleaner through might be a good idea too, in case one of ‘em is gummed up. Quote Link to comment Share on other sites More sharing options...
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