billyblankss Posted February 3, 2021 Share Posted February 3, 2021 Need some help thinking through what is causing this sketchy condition... Driving down the road and if I get into fourth gear (especially noticed this on the highway) and accelerator / RPMs go above 2000 the accelerator gets into this death loop where i take my foot off the gas and it just keeps on going. The only way to get it to stop was to put the clutch in - at this point it continues to spike all the way to max throttle (my Bendix reader was showing it hit 9k almost) and then dies back down to idle RPMs. During the time i was driving and the throttle was sticking, i put my foot under the gas pedal to kind of pull it up to make sure it wasn't the pedal was sticking to the floor or whatever. It didn't affect anything, and when i pulled my foot out from under the throttle it went back to whatever RPM it was stuck on. Brakes did not seem to affect the stuck throttle. Variables that must have led to this: This morning, immediately before this started, I replaced my (87 RENIX) air intake with the spectre cowl induction intake. I installed correctly including the vent hoses to the valve cover and to the charcoal canister. There were remaining original small vacuum hoses, the little tiny diameter ones - that in other threads i have read, are no longer required because they lead to the warm air switch thing for when it cold starts. I have taken those baby little hoses and routed them to their original destination (i think but could be wrong) as best I can, but others have said they just capped them so maybe that's important? Other variable, before installing the intake a couple weeks ago I put in the upgraded ECU per cruzer's suggestion, for the 89-90 Renix. I cannot reasonably just remove the intake and replace with oem at this point becuase many of those old hoses were dry rotted. I looked under the hood at the arm from the throttle body and does not appear to be snagging anywhere. Link to comment Share on other sites More sharing options...
89 MJ Posted February 3, 2021 Share Posted February 3, 2021 10 minutes ago, billyblankss said: my Bendix reader was showing it hit 9k almost That's a lot of RPM for our little stump puller engines. Maybe try a different TB if you have one, maybe that is sticking. Link to comment Share on other sites More sharing options...
billyblankss Posted February 3, 2021 Author Share Posted February 3, 2021 3 minutes ago, 89 MJ said: That's a lot of RPM for our little stump puller engines. Maybe try a different TB if you have one, maybe that is sticking. Maybe, but doubtful - I recently put in the stroker bored TB and it looks pristine. I really wonder if it has something to do with the vacuum hoses. Also didn't seem to happen in lower gears. IDK Link to comment Share on other sites More sharing options...
89 MJ Posted February 3, 2021 Share Posted February 3, 2021 @Pete M, can you please move this over to tech? Link to comment Share on other sites More sharing options...
billyblankss Posted February 3, 2021 Author Share Posted February 3, 2021 1 minute ago, 89 MJ said: @Pete M, can you please move this over to tech? Sorry Pete i put this in the wrong forum. I'm all out of sorts i guess Link to comment Share on other sites More sharing options...
Jesse J Posted February 3, 2021 Share Posted February 3, 2021 that sounds scary Link to comment Share on other sites More sharing options...
jdog Posted February 3, 2021 Share Posted February 3, 2021 Id check the motor mounts, trans mount, if the motors twisting it could cause a bind on the linkage or cable. The only other thing I could think of would be a bad cable or a sticking cruise (if installed) Link to comment Share on other sites More sharing options...
Ωhm Posted February 3, 2021 Share Posted February 3, 2021 Can you move the throttle plate without moving the linkage? Link to comment Share on other sites More sharing options...
billyblankss Posted February 3, 2021 Author Share Posted February 3, 2021 1 hour ago, Ωhm said: Can you move the throttle plate without moving the linkage? Sorry I'm probably dumb not sure what you mean. When I play with the throttle under the hood i pull back on the top part which moves the whole assembly back. There's no play in that arm/plate/spring thing. Link to comment Share on other sites More sharing options...
Ωhm Posted February 3, 2021 Share Posted February 3, 2021 Remember I know what I mean that don't mean others do. Looking down the TB bore can you move the circular throttle plate without moving the linkage, is it loose. Does the throttle plate swing? Link to comment Share on other sites More sharing options...
billyblankss Posted February 3, 2021 Author Share Posted February 3, 2021 3 hours ago, Ωhm said: Remember I know what I mean that don't mean others do. Looking down the TB bore can you move the circular throttle plate without moving the linkage, is it loose. Does the throttle plate swing? You may be on to something. I'm going to take off the boot and check that. I also figured I'd add pictures of the hose situation since it's the last thing I changed before this happened. That skinny hose is unchanged. I know if I remove it the idle shoots up in rpm These two horizontal boots are weird and I'm not sure what to do with them.I noticed when I plugged these hoses the idle and fuel consumption rate goes down. If I take them off the idle shoots up but maybe it would go back down idk. For right now I did the following The top hose I tried to route it where I think it was going originally, to this device or sensor that I don't know what it does. The lower hose originally I just taped and sealed the end of it. There's significant enough pressure/vacuum coming out of it, I have since just left it open... That mystery sensor/vacuum connection has another line next to that yellow looking wire that runs down to this circular thing on the manifold... In the above picture it's the 90 hose Robbie connected to the rusty circular thing. I noticed when I disconnect it nothing seems to happen. That's The throttle body and linkage Link to comment Share on other sites More sharing options...
Ωhm Posted February 3, 2021 Share Posted February 3, 2021 None of those vacuum hoses or even all of them won't get you 9k rpm's. Link to comment Share on other sites More sharing options...
billyblankss Posted February 3, 2021 Author Share Posted February 3, 2021 10 minutes ago, Ωhm said: None of those vacuum hose or even all of them won't get you 9k rpm's. I figured it out because of your suggestion. The throttle body adapter. Clearly can't figure out how to put it on straight. It has a lip that was sticking out directly in the path of that throttle plate /arm It wanted to stop there but with a little more pressure it went past and then gets hung up on the other side I guess dropping it to neutral made it spike in rpms. I'll move this adapter around and see if that resolves completely. That said, i would still love if someone could diagnose the vacuum hoses and that sensor they run to. I'll break out the manual later when I'm back near a computer since it's a pdf. Link to comment Share on other sites More sharing options...
Ωhm Posted February 3, 2021 Share Posted February 3, 2021 5 minutes ago, billyblankss said: I figured it out Link to comment Share on other sites More sharing options...
Ωhm Posted February 6, 2021 Share Posted February 6, 2021 On 2/3/2021 at 6:00 PM, billyblankss said: That said, i would still love if someone could diagnose the vacuum hoses and that sensor they run to. @cruiser54 http://cruiser54.com/?p=121 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now