engine revs to 2000 rpm on its own June 26, 2017, 05:29:19 AM hello, i have a 1988 tc with 121,000 miles, auto, and k&n installed on vam everything else is stock. engine will rev to 2000rpm on its own for 30 to 60 seconds but sometimes it doesnt idle back down. i have to shut motor off and restart to get idle to come down. this is happening multiple times in just short drives. i cant figure out what it is...please help Quote Selected
engine revs to 2000 rpm on its own Reply #1 – June 26, 2017, 05:39:15 AM What do the codes say? Quote Selected
engine revs to 2000 rpm on its own Reply #2 – June 26, 2017, 08:14:01 AM Quote from: Haystack;461561What do the codes say?^^^this^^^Could be a vacuum leak but assuming that has been checked, 99% it's TPS related... The 2.3 are sensitive to voltage setting and 30 years down the road are often defective, won't always give a code... Quote Selected
engine revs to 2000 rpm on its own Reply #3 – June 26, 2017, 08:52:35 AM Try backing off the timing a degree or two. Idle is controlled primarily by timing. I was having similar issues along with what seemed like a constant mis-fire at idle. I ended up programing a chip to put idle timing to about 23* instead of the 25* it's supposed to have. Mis is gone and no more racing idle. You don't need the chip for this, I had a spare and didn't want to do a global change that will effect all driving conditions by just twisting the dizzy. John Quote Selected
engine revs to 2000 rpm on its own Reply #4 – June 26, 2017, 07:19:08 PM I have the Innova 3144 code reader but lost the instructions. I did The key on test and when it cycled through codes they were 11,10,41 and 65 after it was finished memory only showed 65... Taking car to shop tomorrow for a code test...I will also try the timing back off. Quote Selected
engine revs to 2000 rpm on its own Reply #5 – June 26, 2017, 07:26:36 PM 41 is lean o2 sensor, 65 is user error (ignore) 10 doesnt mean anything, and 11 is a system pass.The lean o2 could be a bad fuel pump or preassure regulator, on v-8's its almost always a map sensor or vacuum line problem. Quote Selected
engine revs to 2000 rpm on its own Reply #6 – June 26, 2017, 07:57:46 PM 65 is VAF (vam) below test minimum voltage.Ya sounds like you should just use the paperclip in the test plug and count the CEL flashes.Here are the codes for reference:http://www.turbotbird.com/techinfo/eecprint.gifJohn Quote Selected
engine revs to 2000 rpm on its own Reply #7 – June 26, 2017, 08:23:42 PM Sorry I'm new to this. I know carbs but this is all new. Do I need a new o2 sensor? Can you explain the paper clip thing? How do i raise voltage on the vam? I'm going to clean the vam and check the tube for holes. Quote Selected
engine revs to 2000 rpm on its own Reply #8 – June 26, 2017, 11:26:06 PM What you ran is called KOEO (Key On Engine Off)This presents two groups of codes. First. On demand codes (O). Then Continuous Memory codes (C or M).Code 11--No O error codes.10-- Is the separator between the O codes and the M codes.Code 41--O2 lean, no switching.Code 65 Fuel control problem 2.3L Turbo.It hard to know how old the memory codes are, although they look promising.Does your code reader have a button or switch to reset memory codes. If so, rerun the KOEO and operate the reset while the M codes are reading out.Rerun the KOEO again to verify the codes have been reset. Now if they reoccur after you drive the car you know they are fresh.Run KOER (Key On Engine Running) and see what codes you get. Quote Selected
engine revs to 2000 rpm on its own Reply #9 – June 27, 2017, 02:16:44 AM hello, thanks for the advice. i will try that after i put car together. Took vam out to clean, removed intercooler to clean throttle body and found the turbo hose was bad. Quote Selected
engine revs to 2000 rpm on its own Reply #10 – June 27, 2017, 11:44:41 PM Ok, I cleaned vam, vam hose and throttle body. Replaced hose from intercooler to turbo and disconnected battery.. idle was good for about thirty minutes. Ran codes again and got 10,11,41 and 72. Disconnected battery again ran car for a minute idle back down.. Ran code again got 10,11. Found out from previous owner this started after a top end rebuild. New stock cam, bearings and rockers. Quote Selected
engine revs to 2000 rpm on its own Reply #11 – June 28, 2017, 07:59:33 AM You really need to do the KOER test. It's possible you just need an O2 sensor. Other possibilities include your actually lean caused by intake leaks, issue with fuel system or previous owner messed around with the VAM spring. You could have an exhaust leak between the turbine to the down elbow. It may be a poor rebuild and springs are loose. It could even be as simple as the breather grommet on the rear of the valve cover or valve cover gasket is letting unmetered air into the system. Regardless......you need to start with the simple things.John Quote Selected
engine revs to 2000 rpm on its own Reply #12 – June 28, 2017, 03:06:02 PM I found users manual for an Innova 3145 code reader. Maybe that is close enough to a 3144 to be useful.There is a lot of useful info in this manual. Should be required reading for everyone. https://static.summitracing.com/global/images/instructions/equ-3145.pdf Quote Selected
engine revs to 2000 rpm on its own Reply #13 – June 28, 2017, 11:44:53 PM I adjusted the tps had to turn screw in 3/4 of a turn to get rpm to 740-750 and got voltage to .94 volts. With IAC plugged in idle is 950 to 1000. So far no more high idle. I will run koer in another day or two to see if I get any codes. The o2 sensor is new less then 100 miles. Thanks for all your help..Next project t5 hopefully I can find everything soon. So if any of you has the parts for sale please let me know. Thanks Quote Selected
engine revs to 2000 rpm on its own Reply #14 – June 29, 2017, 09:38:28 AM Quote from: Thedivergent03;461639I adjusted the tps had to turn screw in 3/4 of a turn to get rpm to 740-750 and got voltage to .94 volts. With IAC plugged in idle is 950 to 1000. So far no more high idle. I will run koer in another day or two to see if I get any codes. The o2 sensor is new less then 100 miles. Thanks for all your help..Next project t5 hopefully I can find everything soon. So if any of you has the parts for sale please let me know. ThanksNot exactly the proper method but if it works you're golden...After owning 15 '87-'88 TC, I learned long ago that a high idle that is usually corrected on a restart is TPS related... Never seen a o2 sensor make any difference(or on any other EEC-IV) and replaced a few because of CEL indicating they were not switching... Quote Selected
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