7MGE Will not idle correctly, please help.

surf24365

New Member
Aug 19, 2006
17
0
0
35
New Jersey
Hey Guys, I'm working on a 1987 N/A 5spd transmission car. I have put almost 40 thousand miles on the car since rebuilding the engine after it blew the headgasket at 121,000 with no problems what so ever...untill now... Whats happening is that the car would not idle any lower than 1,100 rpm. I figured the problem was attributed to a bad vaccum line, so spraying some throttle body cleaner lead me to the back of the engine near the EGR valve, i replaced all the vaccum lines in that area and when i checked the egr vaccum modulator per the tsrm, it tested bad. figuring that was the problem i replaced it with a new unit. It did not fix the idle issue and furthermore it caused the engine to cut out around 2500 rpm while driving...could my problem be attributed to the egr valve going bad with only 40,000 miles on it?? any ideas guys??
 

CRE

7M-GE + MAFT Pro + T = :D
Oct 24, 2005
3,485
0
0
Denver, CO
I can't really help with diagnosing the EGR system, but have you also checked the TPS alignment and the ISC? You sure there are no other vacuum leaks?

Sorry I can't be of any more help, at least with a bump someone with more info may pop in. ;)
 

sgtmcboom

New Member
Sep 3, 2006
26
0
0
fort myers florida
I had a bad vac leak that was causing my idle issues it ended up being the first injector botom oring half of it had been pinched durring swap. $2 buck part fixed it.
 

CRE

7M-GE + MAFT Pro + T = :D
Oct 24, 2005
3,485
0
0
Denver, CO
A definite possibility. I always forget that that comes up pretty often. Good suggestion.
 

SkipC

New Member
Feb 12, 2008
8
0
0
Dunkirk, MD
Anytime you have a high idle speed, start by checking that the Throttle Position Sensor (TPS) is adjusted correctly (and is not broken). I have the EGR system completely disconnected (isolated) on my N/A and disconnecting it had no effect on the idle speed.
If the TPS idle switch (IDL terminal) is not on at idle (one of the TSRM checks), the idle speed will go up to 1000-1400 RPM.
Hope This Helps, Skip
 

radero

New Member
Jun 11, 2008
7
0
0
South Carolina
My idle was erratic, but high. It would rev up, almost to 2,000 rpm then drop back down to 1,400 or so and then right back up. Toyota dealer diagnosised it as the Idle Air Control Valve.

It is located on the front side of the manifold, two 12mm screws / 3 hoses / electrical connection. You can find the part online for about $300. FYI: The Toyota dealership by me wanted over $700 for the part and $80 labor to install.
 

Clip

The Magnificent Seven
Oct 16, 2005
2,738
9
38
35
Virginia
radero;1184361 said:
My idle was erratic, but high. It would rev up, almost to 2,000 rpm then drop back down to 1,400 or so and then right back up. Toyota dealer diagnosised it as the Idle Air Control Valve.

It is located on the front side of the manifold, two 12mm screws / 3 hoses / electrical connection. You can find the part online for about $300. FYI: The Toyota dealership by me wanted over $700 for the part and $80 labor to install.

damn, $700?

i'd look on here before i sold my arm and leg and firstborn.
 

surf24365

New Member
Aug 19, 2006
17
0
0
35
New Jersey
Thanks guys, i put a brand new Tps on the engine and it seems to have fixed the idling issues but i'm still having a problem with the engine kind of cutting out or losing power between 2 and 3 thousand rpm under load. almost as if it were hitting some sort of fuel cut? could this just mean i need to adjust the tps more?
 

chefma70

New Member
Mar 19, 2008
404
0
0
Florida
radero;1184361 said:
My idle was erratic, but high. It would rev up, almost to 2,000 rpm then drop back down to 1,400 or so and then right back up. Toyota dealer diagnosised it as the Idle Air Control Valve.

It is located on the front side of the manifold, two 12mm screws / 3 hoses / electrical connection. You can find the part online for about $300. FYI: The Toyota dealership by me wanted over $700 for the part and $80 labor to install.

was your car every idiling properly 6-900? if it was did you ever take the tps off? if you did and with your symptoms you just put it on incorrectly.i had the same problem cause i put it on wrong..rule number one of owning a supra never take it to toyota for labor NEVER they will chop off your arm to make profit. i know people that work there they tell me all the timeif you want examples just ask.