4g61t.org

hi again guyss, i was wondering if anyone has ever come across my problem...
my 4g63t engine has lately been stalling frequently after letting off the throttle.
Also in morning after you start the idle is too high and takes about 15 mins to go down to the normal rev range.
This has been happening since i have had the mass air flow sensor rewired into the harness as the wiring to the senser had been cut out of the harness,as first it was working perfectly but about a month later the staliing and high idle started happening.
the funny thing is the engine ran for about 9 months without the senser and never ever stalled and idle was perfect.
does anyone have any idea on this problem??

Any Check engine lights? Check for vacuum/boost leaks by pressurizing the system.

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89 Mirage Billet 20g 63t 12.4@120 417whp 400wtq @ English Racing.
89 Colt GT E316g
06 Silverado SS
07 ZX6R

no engine check lights........i dont have the colt/mirage/gsr dash,my harness is wired to the original dash of the car which was 4g15 engined so no engine check lights because it doesnt have them:(

Check the wiring that was just installed to the sensor, again. Double check it.

What RPM does it start at?
When the RPM finally falls, what does it sit at?
Does the RPM/idle bounce up and down once warm?

Check the wire going to the switch that is contacted by the wheel on the throttle shaft. The switch will have an ugly rubber cover on it with a zip tie for the wire holding it in tight.
That switch is only for idle, helps on decel too but I think you have a larger issue.

As stated above, if you can shoot brake cleaner spray around the throttle body, intake manifold gasket to head area, vacuum hoses, intake snorkel hose to the throttle body, basically anywhere air can escape, we are looking for a leak. The RPM should rise when you get a leaky spot where the brake cleaner is pulled in. You will have to try this hot with the RPM as low as possible.

Wondering if there also might be a leak internal to the TB where the Fast Idle Air Valve resides. To check that means removing the TB, whether to install the block off plate or re-install after a cleaning and inspection. The large flat plate with all the phillips star shaped screw heads, is the FIAV cavity.

Starts at about 1800 then goes down to about 1100 but aftet about 12 to 15 minutes.
When it goes down it is stable

Your RPM range seems reasonable but should drop quicker than that. Malta cannot be that cold right now, is it? Below freezing?

Check you wires to the coolant temp sensor (2 wire) connection on the thermostat housing. Excessive corrosion causes the ECU to think it is really cold out, maximum -40 C if unplugged = infinite resistance, and so it could be compensating with an extra rich mixture. Check those two terminals for green death. Should be a thick rubber boot over those wires. Go from there ...

Tempetature is about 10 degrees celsius.I'll check the wires but wod thar have anything to do with the stalling??It stalls mainly when suddenly coming off the excellerator and shifted into neutral.

Sounds like a sticky IAC, take that off and clean it up. Check the continuity as well.

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Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

Just saw this now. As Mechacode stated, a sticky or clogged IAC port will cause a stumble when the engine returns to idle, as it has a hard time compensating with enough air as the engine settles. The Idle Stop Switch is also incorporated into this equation, as the ECU does need to see, "off throttle" or between 7-11% on the TPS also. Later models (95+) incorporated the Idle position into the TPS (Throttle position sensor) with a fourth wire.

You can confirm that the idle stop switch works without the wire in place, by putting a test light to battery positive and using the terminal on the ISS as the ground. Open the throttle and it should turn the light off. Circuit to ground is verified and you can look at the wiring if that was ever suspected to be an issue. Check your ISC controller and go from there.

You forgot the fiav. Unless it is blocked off alwhile your coolant lines are bypassed you will have this issue.
Also, make sure biss screw is set right. The o ring hardens and doesnt hold it put any longer. Replace o ring and reset.

The idle stop switch needs to be set correctly and wired it to work as well.

All three of those will make the car idle well of you have no other vaccuum leaks.

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If speed kills, then i shoulda been dead awhile ago. There is no such thing as "Too Much Power". There is no excuse for a lost race. Do you view the rev limiter as a fun limiter?or as a shift point? And we all know, more boost=more fun.

Can you explain exactly where the iac is..not that much of sn expert.

It is on your throttlebody on the bottom. Top image is your throttlebody, bottom image is the IAC. You remove the screws holding it on, then check for debris inside the hole and any carbon buildup on the plunger of the IAC. If it is clean, follow the instructions for testing it on this page: http://www.dsm.org/how-tos/tttt/tttt3.html

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

Thanks for the help so far..would someone by any chance have a link ti
o a wiring diagram for the mas air flow sensor,idike to be sure that it is wired correctly

Have you checked the IAC? I'm 95% sure that's your problem.

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

Yes, totally forgot about that section.