Hey guys, new here. I have been skimming for information for a while. Lots of knowledgeable folks here, so hoping for some help. I have a 99 EFI twin cam hijet that is bogging on acceleration. It idles rough some, but mainly is noticeable in Drive when any gas is given. I have checked fuel pressure, have spark at all 3 coils/plugs, checked timing, vacuum lines, air filter, throttle position sensor, MAP sensor....Out of options other than possibly cam position sensor. I pulled mine today and cold, it reads 1.1K ohms. I cannot find specs on it and was wondering if anyone here knew what the resistance should be cold and hot. Was also wondering if y'all had any other advice should this not be the culprit. Thanks in advance.
look at the idle air system, if the passages or cone get dirty it can cause issues at idle and just off idle. also check the cleaniness of the throttle bore where the butterfly meets it sometimes a slight ring of carbon/dirt can build up there.
ttc, thanks. Ill check that. I called myself checking the throttle body and lines for any buildup. Is there an idle air sensor there that could be checked? How would you check it? Maybe a little more explanation of symptoms wouldn't hurt...Idles a little rough right when cranked, but then smoothes out. Put it in Drive(automatic tranny), and it's a different story.... give it gas, falls on its face. Sometimes i can get the truck to drive up to speed by feathering the gas lightly until it gets up enough to run. At the onset of a hill and extra throttle applied, the engine bogs and almost dies until i get off the gas... then it'll idle fine and the feathering process starts all over. It's like any load at all where accelerating is necessary kills it. For instance, loading on a trailer... idles fine and pulls to the ramps when i let off the brake. I can try to give it gas to pull up the ramps and it bogs, get off the gas and it idles fine again. In park, i can rev the engine without bogging unless i just peg it from nothing to wide open.
99 hijet Did you ever figure out what was dogging your hijet? I have one that is doing the SAME thing and could use some clues.
I haven't figured it out. I give up. Had a mechanic near me recommended by G&R, so I'm going to take it to him... Just gotta make the time to haul it 3 hrs up there. I'll share info once we get it figured out.
I finally took it 7 hours up the road to the guys at G&R Imports. They fixed it. The cam phaser was out of adjustment. The pin that holds it in place had fallen out. They adjusted it, put the pin back in, and put everything back together. She's running like a sewing machine. Steve at G&R has been a great help.
