Continual Idle Problem

smagnotta

smagnotta

SuprSal
Apr 5, 2005
202
0
0
WashPa
Background: Idle problems. I finally resolved the code 51 issue (TPS). Currently, the Super Monitor has no codes (the good).

Car: 87 Supra Turbo with Lexus/550s, Aeromotive AFPR with gauge, Walbro, CT-26 upgraded, HKS boost controller, SAFC Neo.

I have a brand new engine wiring harness, EGR valve, charcoal canister, throttle body, TPS, ISC valve and all the coolant sensors.

Current Problem: Car starts out fine with a higher RPM, and idle and vacuum (around -18) are steady. As the car starts to warm up, the car sputters, the idle fluctuates between 500 RPM to 900 RPMs, the vacuum fluctuates between -12 and -18, it has a miss and the fuel pressure fluctuates (it all happens together). Also, if you accelerate quickly and then release the gas pedal, the car will stall and shut off.

I want to test the Aeromotive AFPR/fuel system. Can anyone step me through it or offer a link? Any other checks I can perform?
 
S

supramad77

supramad
Feb 5, 2006
331
2
18
Dartmouth, Devon, UK
smagnotta said:
Background: Idle problems. I finally resolved the code 51 issue (TPS). Currently, the Super Monitor has no codes (the good).

Car: 87 Supra Turbo with Lexus/550s, Aeromotive AFPR with gauge, Walbro, CT-26 upgraded, HKS boost controller, SAFC Neo.

I have a brand new engine wiring harness, EGR valve, charcoal canister, throttle body, TPS, ISC valve and all the coolant sensors.

Current Problem: Car starts out fine with a higher RPM, and idle and vacuum (around -18) are steady. As the car starts to warm up, the car sputters, the idle fluctuates between 500 RPM to 900 RPMs, the vacuum fluctuates between -12 and -18, it has a miss and the fuel pressure fluctuates (it all happens together). Also, if you accelerate quickly and then release the gas pedal, the car will stall and shut off.

I want to test the Aeromotive AFPR/fuel system. Can anyone step me through it or offer a link? Any other checks I can perform?
Click to expand...

Damm this sounds like my car. Similar mods two. Mine is a auto that is trying to stall on me after i boot it. Only when it's warmed up though.
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
202
0
0
WashPa
supramad77 said:
Damm this sounds like my car. Similar mods two. Mine is a auto that is trying to stall on me after i boot it. Only when it's warmed up though.
Click to expand...

It seems that these cars are very sensitive to any air/fuel/timing changes. I have the 87 TSRM and multimeter so I can test the stock parts but I have a lot of mods. That code 51 was a real pain.

The engine sounds strong and fine across the RPM range -- it's just this damn idle problem. I have had it intermittently since I got this car in 1999. I have done so much to this car and it has so many new parts you would think by now (8 years later) this problem would be resolved.
 
S

supramad77

supramad
Feb 5, 2006
331
2
18
Dartmouth, Devon, UK
smagnotta said:
It seems that these cars are very sensitive to any air/fuel/timing changes. I have the 87 TSRM and multimeter so I can test the stock parts but I have a lot of mods. That code 51 was a real pain.

The engine sounds strong and fine across the RPM range -- it's just this damn idle problem. I have had it intermittently since I got this car in 1999. I have done so much to this car and it has so many new parts you would think by now (8 years later) this problem would be resolved.
Click to expand...
yea i just had a hg rebuild with the apexi safcii fitted and and avc-r boost control. Also have the afpr and 550's with the lexus afm. Mine is showing 51 when revved up. Did have some misfiring the other day but mostly trying to stall after i lift off.
 
mhopemk3

mhopemk3

The CT install SPECIALIST
Jul 13, 2005
762
0
0
52
Jacksonville, FL 32277
With those vac readings you could have a little leak somewhere. Int man gaskets maybe.. You vac should be pretty steady. Mine is -20 on idle no fluctuation. When driving and letting off the throttle I pull 25-26 vac. Check for leaks. When I took my old manifold apart the gasket had cracks all through it. Good luck!
 
jdub

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
1
38
Valley of the Sun
Check your ISCV to make sure it's working. A good cleaning woud be a good idea as well. If the check valve under the ISCV is clogged, replace it.
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
202
0
0
WashPa
With those vac readings you could have a little leak somewhere. Int man gaskets maybe.. You vac should be pretty steady. Mine is -20 on idle no fluctuation. When driving and letting off the throttle I pull 25-26 vac. Check for leaks. When I took my old manifold apart the gasket had cracks all through it. Good luck!
Click to expand...

The car has a new ISC valve, and associated parts. All my new parts function as per the TSRM.

I am leaning on a leak, leak(s) somewhere. I will test for leaks with a boost leak tester on the turbo inlet - where the accordian hose goes.
 
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smagnotta

smagnotta

SuprSal
Apr 5, 2005
202
0
0
WashPa
Will do; I am going to do the boost leak test and then I am going to check the fuel system via the 87 TSRM. At that point, I may start going around the engine again with my multimeter.
 
ImperfectSupra

ImperfectSupra

New Member
May 19, 2007
163
0
0
Virginia Beach
drjonez said:
vac will be lower @ cold idle....
Click to expand...
i have similar problem. my rpm isnt higher then idle on cold starts and the rpm would flutuate between 500 and 700, i have no codes and the car acclerate great, just the exhaust popping when i let off the gas not stalling. any idea, Dr. J or anybody?
 
F_T_F

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
will some one please tell me what the dashpot is and what its function is or even a picture of it. in the contunual idle problem it keeps showing up in my searches and need to verify its working properly
 
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