Michael Savage Posted July 21, 2014 Report Share Posted July 21, 2014 My car 1995 Monte Carlo 3100 Custom has had a really low Cruise RPM for the past year or so. I've replaced almost everything since then and pretty much guessed it was the Transmission. Yesterday I went to pull a part and I looked at the one thing I had never even thought about. That little Sensor on my intake tube. Well mine is long and had a metal wheel looking thing inside a cage, it looked as if it was covers in soot. I picked up 2 that looked new off a 03 the short style and one like mine off a 95 (looked brand new). Stuck the small one in the hole from the 03 and the low cruise RPMs was up higher. At 55 it would cruise at 1300RPM now it cruises at about 1700-1900RPM. Figured IDE mention this on here so if anyone else had this issue throw a dollar to a scrap yard and grab one that looks good. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 21, 2014 Report Share Posted July 21, 2014 summary: my car was operating correctly, now it isn't. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 21, 2014 Report Share Posted July 21, 2014 That sounds like my issue with my Cutlass. Cruising at 55 is around 1700 - 1900 rpm and cruising at 60 is 2000rpm. If I want to drive 70mph, then the engine revs to 3000-3500 rpm... My problem? The trans is not going into 4th, and the computer only recognizes up to 3rd gear. (Checked it with Tuner pro). Won't trigger the SES light but it does store codes, which wind up being the TCC solenoid and 3/4 gear solenoid. What's my point? The engine is SUPPOSED to cruise at 1300rpm at 55mph because it's in 4th gear or "overdrive gear" as some call it. It's supposed to go up to 1700rpm at 6500 and 2000-2200 around 70mph. It's set up this way for fuel economy. The OP could have gotten the desired higher RPMs by simply dropping to 3rd gear. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 21, 2014 Report Share Posted July 21, 2014 i think that is what happened..... the PCM isn't liking something and is now disabling 4th gear(or TCC lock). Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted July 21, 2014 Report Share Posted July 21, 2014 I've had similar issues with the T460E in my Cutlass...I want to be careful not to steer you in the wrong direction, but after eliminating the simple things, the only fix was to have the transmission rebuilt. and even then, it took a second effort by the transmission shop to correct the problem. In my case, the TCC apply piston was sticking in the bore in the valve body; according to my transmission guy, an all too common problem with the T460E. What code are you getting? i think that is what happened..... the PCM isn't liking something and is now disabling 4th gear(or TCC lock). Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted July 21, 2014 Report Share Posted July 21, 2014 ..by "code" I meant the actual code...thinking twice about my issue, though, it was temperature dependent. When the trans was cold, it operated perfectly--above 175 degrees, the ECM locked out 4th gear, because it detected excessive slip from the TCC. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted July 21, 2014 Author Report Share Posted July 21, 2014 Well with mine at 1300rpm cruising the engine would sputter and stuff now the RPMs don't drop 1000rpm from foot cruising at 2300rpm to 1300 which causes sputtering. Which I'm guessing is a missfire. The new 2 I put on both keep the RPMs between 1600-1800rpm which keeps it cruising but doesn't just drop it too low. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted July 21, 2014 Author Report Share Posted July 21, 2014 Previously before the sensor malfunctioned the engine used to run at 1500-1900 RPMs with cursing around 55. Then something went bad and it started cruising lower between 1100-1300 rpm. Which causing sputtering now it's back where it originally was. Not saying I'm correct, but I've noticed the car runs better when cruising. Without sputtering. Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted July 21, 2014 Report Share Posted July 21, 2014 99% of the time, what you're describing is an ignition issue--either plugs, wires, coil, or ICM. Well with mine at 1300rpm cruising the engine would sputter and stuff now the RPMs don't drop 1000rpm from foot cruising at 2300rpm to 1300 which causes sputtering. Which I'm guessing is a missfire. The new 2 I put on both keep the RPMs between 1600-1800rpm which keeps it cruising but doesn't just drop it too low. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 22, 2014 Report Share Posted July 22, 2014 ..by "code" I meant the actual code...thinking twice about my issue, though, it was temperature dependent. When the trans was cold, it operated perfectly--above 175 degrees, the ECM locked out 4th gear, because it detected excessive slip from the TCC. I started my own thread. Robert is welcome to go see as well. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted July 22, 2014 Author Report Share Posted July 22, 2014 I've changed the plugs, wires, coils and ICM since it's started. I hadn't replaced that Vaccum Sensor because I never paid attention to it. I've got a Brand New one 95 style and the 03 stub I got from pull a part. I've used both of them and they both keep cruising speed slightly higher to where it doesn't sputter, and all around drives better. I've put the old one on and it creates the low cursing speed. I mean cursing at 30 it cruises at 1100rpm 45 about 1400 and 55 around 1500-1900 just going by the gauge and 65 is 1800-2000 75 2100-2300 now prior to the switch it would cruise at 30 at 700-900 the whole way cruising was low too low so it sputtered a bit it's done it for about 2-3 years and swapped everything pretty much except that sensor. So i figured IDE share this to anyone who might have that issue. I've never even paid attention to that sensor before I knew it was there but didn't know or care what it did because I've never heard about them going bad. This is what I know from just swapping them, it did make a difference. Even using the one for my car from autozone upped my RPMs to about the same as the short 03 model one I got from pull a part. So that tells me that the sensor was bad or 2/3 of them I have are bad including the brand new one and the one off the 03 and the old one that came on my car is still good. Quote Link to comment Share on other sites More sharing options...
ron350 Posted July 22, 2014 Report Share Posted July 22, 2014 What part exactly did you change? Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted July 23, 2014 Author Report Share Posted July 23, 2014 The from Vaccum Sensor I believe. It the nub with the 2 pin connector on the intake hose. Mine looked burnt and i just picked on up that looked new and it made a difference. Went ahead and bought a brand new one and it had the same effect. Quote Link to comment Share on other sites More sharing options...
ron350 Posted July 23, 2014 Report Share Posted July 23, 2014 Is it one of these? http://www.rockauto.com/catalog/x,carcode,1056417,parttype,5072 Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted July 23, 2014 Report Share Posted July 23, 2014 ..wouldn't that be an intake air temp sensor? Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 23, 2014 Report Share Posted July 23, 2014 I believe so Galaxie... I believe so. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted July 24, 2014 Author Report Share Posted July 24, 2014 I guess it's because it adjusts spark timing according to air density that it made a difference. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted July 24, 2014 Author Report Share Posted July 24, 2014 If mine was bad that does fully explain why it runs better with the new one, because the spark timing wasn't accurate I wasn't burning my fuel efficiently which lowers performance.1 Which when cruising at low RPMs due to not burning fuel efficiently. Now it makes perfect sense. Quote Link to comment Share on other sites More sharing options...
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