OH WHAT NOW??? IDLE IS RISING THEN REALLY RISES! (pics)

Okay... more crap happening....

This link deals with my MAF problems.

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/maf-help-t6448.htm

Put the second MAF in ran fine. Went to work today, went to lunch..fine.. on way home, right before home I notice something weird...

Stop and go traffic...very slow, when I let off the gas, the car kept going...weird..put in neutral it rises to 1500 RMP..should be closer to 700..

Get in garage, rev it a bit and stays high...then really rises almost to redline, then falls to 1500 RPM...no SES light...

Checked the damn vacuum lines...seem okay..

But what is this part? When I start it, about 20 seconds later, this makes a weird buzzing sound..


I've looked all over the lines. I unplugged the IAC...I put back in my old MAF...I unplugged the MAP, put in my old MAP, unplugged whatever the pic shows...

I'm LOST! Could I be missing a vacuum line?

what is this? I the vac line has a mesh in it


What is this? The first pic has a vac line to it, and a fuel line is connected too..and a weird rubber connector with no line connected to it....



To summarize:
Drove car all day, fine...come home at slow stop & go...car idles too high...in garage..revs really high (once buzzing starts...the revs slowly start to rise)

I'm going to check my shop manual too...but shit! I'm lost!

Sorry this is so long

OH, when it first did it, I unplugged the MAF and it fell just a bit...but stayed high. When I revved it, it then sunk and died (as should happen) but when I first unplugged...remained at slightly higer idle.

Could a vac problem cause revs to rise almost to redline for about 4 seconds then fall again?

THANKS GUYS, YOU ARE ALL A GREAT RESOURCE!!!!

all this happens when car is in park by the way...in my garage as I work on it...

you figure out what happens and let me know. My friend is having thing same issues with his car. In park it just revs higher and higher. It holds for him about 3000 to 4000 RPMs. When he puts the pedal down the rpms drop then slowly build back up on their own. So if you get any leads let me know. id like to fix my buds car too.

Double check for vacuum leaks, also look closely at the IAC. That thing you are pointing to with the red arrow is the evap solenoid.

that metal thing you are pointing to is the vac controlled solenoid for our '96's transmission. i cant remember if there is a mesh in there, but it wouldnt surprise me. (probably there in so if the diaphragm inside breaks, it doesnt suck up trans fluid into the engine)
Your vac lines look like they all go to the right places from the pics. only one not shown is the one that goes from under the snout to the MAP sensor.
Do you have any pending codes?

took to Advanced Auto. P0102 (probably from my old MAF) and P0507! Idle speed high...they cleared codes

But guess what, car drives fine...went for a spin, temp normal & such..

DO you guys think the enginer cover can be a heat trap and if a part if about to fail due to heat stress, that the cover just helps that happen (that's just a side thought)

But right now it's running fine....

weird.
I'll see what shop manual says of P0507

#1 the vacuum connections by the MAF. Two connections, bottom one goes to #2 which is down on the tranny (not shown). Top one goes to #8

#2 A connection on top of the tranny. This is a part with a mesh in it to prevent junk from entering rest of system from tranny

#3 The controller for the boost gauge has 2 connections

#4 A vacuum connection for 3 lines (top to #1, middle to #3, bottom to #9)

#5 The connection with the brake booster

#6 the MAF

#7 A "T" connector from #6 to #10. The bottom of the "T" is plugged off

#8 The Evap Solenoid. There's two connections. The closest to camera goes to #1, the farthest one connects to another part... This other part has three connections. One to the solenoid, the other is connected to a fuel return line, and the last to an "L" rubber connector which isn't connected to anything..which seems weird

#9 Connects to #4..not sure what this is

#10 Under the S/C snout is another connector which connects to #7. The other part of the "T"

I've replaced most of these rubber connectors...They don't make exact OEM replacements so it's a hob-knodge of parts put together from the autoparts store. But I think it works okay, the connections are tight, there's no bent or cut lines.

Wolfmaster579 wrote:

you figure out what happens and let me know. My friend is having thing same issues with his car. In park it just revs higher and higher. It holds for him about 3000 to 4000 RPMs. When he puts the pedal down the rpms drop then slowly build back up on their own. So if you get any leads let me know. id like to fix my buds car too.

I would definately check the IAC, clean it..replace if necessary. Check ALL the connections I show above, make sure the rubber isn't rotten, lines aren't broken... make sure the throttle body isn't blocked with debris, clean the MAF with MAF cleaner.....

Okay gang, I went down today, took off the IAC again, looks fine, double checked all connections..took off the air filter tubing and started her...she didn't want to run..but did...made a wicked hissing sound as air was pulled through the mesh ...but it ran eventually... put it all back together and went for a drive...no problem....went for another 20 minute leisure drive...nothing...drives like a dream..some noise from tranny at stoplights while in drive...but that's not a cause...

So...the P0507 is gone, and it's running fine...I'll keep an eye on her and we'll see what happens!

It could be the TPS. I had almost identical issues on a 99' Grand Am where rpms would intermittendly climb for no reason. The car felt starved for power a little as well. At startup, the rpms would start around 1500 and climb almost past 3000. Scared the hell out of me. When driving, if I let off the gas, the rpms would climb past 2000. Sitting at a traffic light was unnerving. I was able to reset the TPS before startup by pumping the gas pedal.

It was annoying because all signs pointed to it being a vac leak except it would just fix iteself. Thought it was the IAC but replacing that didn't fix it.

HTH

Rick, get your butt back over to your thread and tell us about your vendor problem!

Wondering if perhaps, the parts, being old...got heat soaked sitting under the engine cover (which is off for now) and failed...

I don't know...it's odd. I'll continue to drive it, alone and my wife won't be driving it anytime soon..

Might not hurt to get new IAC, new MAF and new Evap Solonoid to be safe....

1998 Riv wrote:

Rick, get your butt back over to your thread and tell us about your vendor problem!

Thanks for reminding me Dave. I completely forgot.

Nate,
Do yourself a favor and read up on how these systems work before blindly replacing the certain valves "just to be safe".
You will find for instance that the EVAP system has other things in there that can cause the solenoid to be activated when it shouldn't.
Do you understand? You need to test the other things, as well, before spending good money, and you'll learn some things in the process.
At least that's how I approach problems like this and learn at the same time.

I've a shop manual Rick...my point is (and I don't have any test equipment)...is that the parts are most probably 14 years old...nothing last forever. Replace a part here and there over time..till I'm sure it's newer..

I've already replaced some parts as they failed in the past..this is nothing different

But, with the cover off, I've driven for two days now...runs fine.. I do have my wonders on the torque converter (shifts fine, but there's a bearing type rattle at stoplights in drive).,..

Overall it's good.