4A-GE MK1 Engine Silvertop high idle

IkoIKo · 11-08-2009, 06:17 PM

My silvertop idles at 2,100 rpms and is running rich. I've set the timing to 10 BTDC, replaced plugs, wires, cap, rotor. I tested the ISCV and it works off the car. Tested the water temp sensor and it's OK. Prior to replacing the tune up parts it ran rich but idled rough and unstable around 1,000, sometimes it would die.
The swap wasn't done by me and some of the work is suspect. Where should I spend my time? Tracking down wiring to be sure stuff is correctly wired, fuel pressure regulator, throttle position sensor, or something else I've completely missed?

mr220v · 11-10-2009, 03:56 PM

A vacuum leak would be the first thing to look for. Aside from that, checking for error codes is a must.

If the wiring is really bad, I could make you something that would put you on solid ground as far as that's concerned.

IkoIKo · 11-15-2009, 07:00 PM

Sorry for the long post. I'm trying to see if any of my observations are useful to anyone else.
Following up on MR220V;
I found a bad vacuum line and replaced that.
Using the blacktop manual I checked the codes and found none.
I did some checks at the ECU and so far it looks good (I could still do more I suppose)
I drove around a bit last week and noticed the temperature drop to below 1/4 on the gauge. I replaced the thermostat and now it idles better and runs better overall.
I drove around today for 45 minutes - high and low speed, fast and slow acceleration. It is still running rich (smell and occasional popping in the muffler on deceleration). It idles at 1200 now and is smoother than it was last week at 2000. I did notice that sometimes it'll idle at 1200 and other times at 1800 or so even after it is warmed up.

Now to my question, this engine doesn't have an air temperature sensor. Is the missing air temperature sensor a problem and causing this engine to run rich and have a high, and inconsistent, idle?

BTW on my drive today the clutch master cylinder lost it's fluid. No obvious leaks so I have another thing to track down...

11-08-2009, 06:17 PM	#1 (permalink)
IkoIKo No Skills Join Date: Jun 2009 Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (2/100% )	Silvertop high idle My silvertop idles at 2,100 rpms and is running rich. I've set the timing to 10 BTDC, replaced plugs, wires, cap, rotor. I tested the ISCV and it works off the car. Tested the water temp sensor and it's OK. Prior to replacing the tune up parts it ran rich but idled rough and unstable around 1,000, sometimes it would die. The swap wasn't done by me and some of the work is suspect. Where should I spend my time? Tracking down wiring to be sure stuff is correctly wired, fuel pressure regulator, throttle position sensor, or something else I've completely missed?

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11-10-2009, 03:56 PM	#2 (permalink)
mr220v Beams Owners Group Join Date: Mar 2006 Posts: 2,529 Thanks: 13 Thanked 176 Times in 147 Posts iTrader Rating: (11/100% )	A vacuum leak would be the first thing to look for. Aside from that, checking for error codes is a must. If the wiring is really bad, I could make you something that would put you on solid ground as far as that's concerned.

11-15-2009, 07:00 PM	#3 (permalink)
IkoIKo No Skills Join Date: Jun 2009 Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (2/100% )	Sorry for the long post. I'm trying to see if any of my observations are useful to anyone else. Following up on MR220V; I found a bad vacuum line and replaced that. Using the blacktop manual I checked the codes and found none. I did some checks at the ECU and so far it looks good (I could still do more I suppose) I drove around a bit last week and noticed the temperature drop to below 1/4 on the gauge. I replaced the thermostat and now it idles better and runs better overall. I drove around today for 45 minutes - high and low speed, fast and slow acceleration. It is still running rich (smell and occasional popping in the muffler on deceleration). It idles at 1200 now and is smoother than it was last week at 2000. I did notice that sometimes it'll idle at 1200 and other times at 1800 or so even after it is warmed up. Now to my question, this engine doesn't have an air temperature sensor. Is the missing air temperature sensor a problem and causing this engine to run rich and have a high, and inconsistent, idle? BTW on my drive today the clutch master cylinder lost it's fluid. No obvious leaks so I have another thing to track down...