Surge
Thread Starter
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Joined: Oct 2014
Posts: 82
Likes: 0
From: Marietta Georgia
Surge
I am still plugging away and have now spent more on parts than I did on the car. Don't get me wrong, I realize that eventually the car will need them. This car was loved - just not very much.
I am still experiencing engine surge. Cold idle works great. Starts at around 1,100 rpm and drops to about 700 - 800 when at about 130deg. The problem is when I take it out on the road. Comeing to a stop the engine idles at around 10,000 to 11,000 rpm. If I give the gas pedal a quick stomp it goes to 700 rpm.
I replaced TPS and set idle per instructions suggested on this site. Checked for vacuum leaks but can not find any. Air filter, plugs, wires, cap, rotor, EGR, AIR - all new.
I am thinking about purchasing a new TB from Performance or BBK. Would this maybe solve the problem?
Thanks
I am still experiencing engine surge. Cold idle works great. Starts at around 1,100 rpm and drops to about 700 - 800 when at about 130deg. The problem is when I take it out on the road. Comeing to a stop the engine idles at around 10,000 to 11,000 rpm. If I give the gas pedal a quick stomp it goes to 700 rpm.
I replaced TPS and set idle per instructions suggested on this site. Checked for vacuum leaks but can not find any. Air filter, plugs, wires, cap, rotor, EGR, AIR - all new.
I am thinking about purchasing a new TB from Performance or BBK. Would this maybe solve the problem?
Thanks
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Check TB spring to see if it is binding and holding TB blades open. Assume that you have keyed in to many "0's" for RPM. IF your at 10,000 to 11,000 your engine would fly apart. L98 maxes out about 5,5000-6,000 RPM at red line.
Thread Starter
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Joined: Oct 2014
Posts: 82
Likes: 0
From: Marietta Georgia
I have already removed the cruise cable.
Car ran high idel at lunch and then perfect 600 to 700 on way home from work.
Thread Starter
Advanced
Joined: Oct 2014
Posts: 82
Likes: 0
From: Marietta Georgia
A bit confused. High idle until yesterday. I went to lunch got back in car and it had a hard time starting. It seemed starved for fuel. Once it started I drove to work. When I came out of work several hours later the car started and ran perfectly. Idled at 600 to 700 rpm at home at all red lights. Got up this morning and It runs perfect - all stop lights 600-700 rpms.
I don't want to look a gift horse in the mouth but what would make it suddenly start running right? If it goes back to idling high at stops what could I look for?
Could it still be my throttle body if it is now running right.
The only thing I have yet to replace is the Throttle Position Sensor TPS
Any input appreciated.
I don't want to look a gift horse in the mouth but what would make it suddenly start running right? If it goes back to idling high at stops what could I look for?
Could it still be my throttle body if it is now running right.
The only thing I have yet to replace is the Throttle Position Sensor TPS
Any input appreciated.
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
The throttle plate shaft gets gummed up from dirt and debris over the years and sometimes will stick in a slightly opening position. The next time it happens, pull over and open your hood. Move the throttle linkage to it's closed position and if the idle goes back down to normal, that is your problem.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
It could be what Daniel is saying above , or it could be the shaft that runs through the Throttle blades has enlarged the holes in the throttle body causing binding. ...After many years of use the shaft will enlarge the holes on the sides of the throttle body which causes the throttle blades to bind in their openings.. ...What makes me think this could be the problem is you said when you kicked the gas pedel the idle went back to normal...This is the way they act with this problem..There are a few repair companys that put bushings on the shaft to center it in the TB, doing this stops the blades from binding....WW
Last edited by WW7; Jan 21, 2015 at 01:08 PM.
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Oil Producer
Joined: Apr 2014
Posts: 9,360
Likes: 2,732
clean our tb housing, take it right off, get in there like your digging for gold.
all passageways.
might as well do the cigar smoke test on the your vacum system but i doubt its that. sounds mechanical as the boys above have said.
might as well do the cigar smoke test on the your vacum system but i doubt its that. sounds mechanical as the boys above have said.
