Still having starting issues, '97 with VQ35
10-08-2005, 10:39 PM
#1
Still having starting issues, '97 with VQ35
I made a thread earlier pertaining to my cold start issue. Here's what's happening after the car has been sitting a while intermittently, or say 9 times out of 10 if the car has not been running for more than 12 hours, I'll start the car the rpms will shoot up to 1000-1100 then bog down to 200 as if the car is about to stall then rise back up to 1000-1100.
It did it tonight after the car had been sitting for over a few hours. I've cleaned the TB, and the IACV thru the hose. I've checked resistance on ECTS (it's good), I also disconnected the MAF and started it, it started up the same but ofcourse threw a code. I also got another code, the code for the front right heated O2 sensor. But that sensor is a brand new aftermarket BOSCH sensor. That sensor is only 2 months old, and the code ONLY came up AFTER the SES light came on for the MAF sensor. I resetted the ECU, started up the car after that no SES light then but then again I haven't driven the car.
I also smell a little bit of fuel when the car seems like its about to stall. But I don't smell anything when it's running, nor after I start it when it's warm. I hear the fuel pump turning on. I doubt it's the injectors because then the problem would be constant. I also doubt it's the FPR because that would be constant as well. There's no vacuum leak that I can hear, and if there was a vacuum leak it would be constant and make my idle fluctuate. My idle after the car has started and warmed up is silky smooth.
My only other guess is the IACV sticking while its opening and closing. Can IACVs only cause cold start issues, and function fine when the car is warm?
I really need to get this fixed ASAP because it's my daily driver and I don't want any problems in the real cold months. Please help.
It did it tonight after the car had been sitting for over a few hours. I've cleaned the TB, and the IACV thru the hose. I've checked resistance on ECTS (it's good), I also disconnected the MAF and started it, it started up the same but ofcourse threw a code. I also got another code, the code for the front right heated O2 sensor. But that sensor is a brand new aftermarket BOSCH sensor. That sensor is only 2 months old, and the code ONLY came up AFTER the SES light came on for the MAF sensor. I resetted the ECU, started up the car after that no SES light then but then again I haven't driven the car.
I also smell a little bit of fuel when the car seems like its about to stall. But I don't smell anything when it's running, nor after I start it when it's warm. I hear the fuel pump turning on. I doubt it's the injectors because then the problem would be constant. I also doubt it's the FPR because that would be constant as well. There's no vacuum leak that I can hear, and if there was a vacuum leak it would be constant and make my idle fluctuate. My idle after the car has started and warmed up is silky smooth.
My only other guess is the IACV sticking while its opening and closing. Can IACVs only cause cold start issues, and function fine when the car is warm?
I really need to get this fixed ASAP because it's my daily driver and I don't want any problems in the real cold months. Please help.
10-09-2005, 06:52 AM
#2
Member who somehow became The President of The SE-L Club
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Harris,
There is a fast idle cam and plunger that opens the throttle slightly when the car is cold. Check to make sure that the plunger that pushes up against the cam and follower is indeed working. It's located under the throttle body just to the left. Follow the throttle linkage and you'll see it. The plunger should be out when the car is cold and push on the cam and follower. There is a scribe mark on the cam and follower that should line up when it's cold as well. Check to make sure that your throttle is slightly opened up first thing in the morning before you start your car. Look closely at the default throttle stop at the set screw, you should see the throttle is pushed off the stop by about 1 or 2 mm. If thats not happening, check the adjustment of the fast idle linkage, or it may just need to be lubricated.
Your cold start should rev up to at least 1500 RPM's then come down a bit as the IACV takes over.
There is a fast idle cam and plunger that opens the throttle slightly when the car is cold. Check to make sure that the plunger that pushes up against the cam and follower is indeed working. It's located under the throttle body just to the left. Follow the throttle linkage and you'll see it. The plunger should be out when the car is cold and push on the cam and follower. There is a scribe mark on the cam and follower that should line up when it's cold as well. Check to make sure that your throttle is slightly opened up first thing in the morning before you start your car. Look closely at the default throttle stop at the set screw, you should see the throttle is pushed off the stop by about 1 or 2 mm. If thats not happening, check the adjustment of the fast idle linkage, or it may just need to be lubricated.
Your cold start should rev up to at least 1500 RPM's then come down a bit as the IACV takes over.
10-09-2005, 08:42 AM
#3
Originally Posted by njmaxseltd
Harris,
There is a fast idle cam and plunger that opens the throttle slightly when the car is cold. Check to make sure that the plunger that pushes up against the cam and follower is indeed working. It's located under the throttle body just to the left. Follow the throttle linkage and you'll see it. The plunger should be out when the car is cold and push on the cam and follower. There is a scribe mark on the cam and follower that should line up when it's cold as well. Check to make sure that your throttle is slightly opened up first thing in the morning before you start your car. Look closely at the default throttle stop at the set screw, you should see the throttle is pushed off the stop by about 1 or 2 mm. If thats not happening, check the adjustment of the fast idle linkage, or it may just need to be lubricated.
Your cold start should rev up to at least 1500 RPM's then come down a bit as the IACV takes over.
There is a fast idle cam and plunger that opens the throttle slightly when the car is cold. Check to make sure that the plunger that pushes up against the cam and follower is indeed working. It's located under the throttle body just to the left. Follow the throttle linkage and you'll see it. The plunger should be out when the car is cold and push on the cam and follower. There is a scribe mark on the cam and follower that should line up when it's cold as well. Check to make sure that your throttle is slightly opened up first thing in the morning before you start your car. Look closely at the default throttle stop at the set screw, you should see the throttle is pushed off the stop by about 1 or 2 mm. If thats not happening, check the adjustment of the fast idle linkage, or it may just need to be lubricated.
Your cold start should rev up to at least 1500 RPM's then come down a bit as the IACV takes over.
10-09-2005, 10:05 AM
#5
Any more details on the fast cam idle plunger is it that thin little rod behind the shift linakages with a plastic piece over it? I don't see any marks, nor a way to adjust it if that is indeed it.
10-09-2005, 12:46 PM
#6
Member who somehow became The President of The SE-L Club
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A picture would be the best way for you to see exactly what and where it is. Unfortunately I don't have any. The Haynes shop manual has a picture and the adjustment procedure. My Haynes is for the 4th gen, your 3.5 might be slightly different.
10-09-2005, 08:02 PM
#7
Senior Member
Join Date: Dec 2004
Posts: 132
can you swap IAC with someone? also wouldnt hurt to clean all terminals on the battery and body.
o2 wont matter on a cold start, it will be in open loop. o2 sensor input is "considered" after the computer goes into closed loop, usually after a few minutes of running.
o2 wont matter on a cold start, it will be in open loop. o2 sensor input is "considered" after the computer goes into closed loop, usually after a few minutes of running.
10-10-2005, 10:55 AM
#8
***UPDATE***
I started it up today first thing as it had been sitting for a little over 24 hours, started up on the first try RPMS shoot up to 1200 or so but the car sounded just a little funny like it wasn't getting enough air, or fuel. But I didn't really smell any fuel, and I'm 99% sure it's not fuel related I'll tell why in a second. Ok so I take out the key start it up again, the first time I started it I only let it run for 5 seconds, the second time it started it stalled. RPMs shot up then it tried to stay on but it stalled. Third time same thing, fourth time it did stay on. So I was like hmmm. I know it's not the MAF, so I'm pretty sure it's the IACV. Now here's the deal after the fourth try, it started up perfectly each and everytime RPMS shoot up to a nice 1400-1500 then gradually came down as the car warmed up. When the car is warm it starts up each and everytime no problem which is why I'm almost positive it's not fuel related because it would then obviously be much more consistent. I'm pretty sure it's not the MAF because I've unplugged it and it started up the same.
I also adjusted the the screw for the TB, the one that has a nut attached to it. I also sprayed some carb cleaner, and silicone cleaner on the throttle linkage. My only guess now is the IACV but I need your guys input. Since this ONLY happens first thing in the morning or afternoon, or when I first start it after it's been sitting a while it leads me to believe the IACV is sticking. Can the IACV ONLY stick the first time the car is being started and not stick for the remainder of the day? Because again once it starts up and has been running it has 0 problems.
I started it up today first thing as it had been sitting for a little over 24 hours, started up on the first try RPMS shoot up to 1200 or so but the car sounded just a little funny like it wasn't getting enough air, or fuel. But I didn't really smell any fuel, and I'm 99% sure it's not fuel related I'll tell why in a second. Ok so I take out the key start it up again, the first time I started it I only let it run for 5 seconds, the second time it started it stalled. RPMs shot up then it tried to stay on but it stalled. Third time same thing, fourth time it did stay on. So I was like hmmm. I know it's not the MAF, so I'm pretty sure it's the IACV. Now here's the deal after the fourth try, it started up perfectly each and everytime RPMS shoot up to a nice 1400-1500 then gradually came down as the car warmed up. When the car is warm it starts up each and everytime no problem which is why I'm almost positive it's not fuel related because it would then obviously be much more consistent. I'm pretty sure it's not the MAF because I've unplugged it and it started up the same.
I also adjusted the the screw for the TB, the one that has a nut attached to it. I also sprayed some carb cleaner, and silicone cleaner on the throttle linkage. My only guess now is the IACV but I need your guys input. Since this ONLY happens first thing in the morning or afternoon, or when I first start it after it's been sitting a while it leads me to believe the IACV is sticking. Can the IACV ONLY stick the first time the car is being started and not stick for the remainder of the day? Because again once it starts up and has been running it has 0 problems.
10-12-2005, 04:49 AM
#13
Member who somehow became The President of The SE-L Club
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Originally Posted by HarrisH
It was the little gold screw that pushes the plunger, the screw that has the (on the '00 TB) 9MM bolt attached to it. It's between the TB and the throttle linkage.
10-13-2005, 02:18 PM
#14
Sounds like the IACV. If it's cold, it can stick. So that would make sense that it only happens when you're first starting the car for the day, it's part of the reason there are coolant lines to the TB. On my wife's Integra, we removed the coolant lines to the TB to run them to the turbo, and that caused terrible cold start issues similar to what you're experiencing, but worse since the IACV never warmed up. It would fluctuate at idle, you would smell fuel, and so on. Ran the coolant lines back to the TB, problem solved.
I would definitely check the IACV.
I would definitely check the IACV.
Originally Posted by HarrisH
***UPDATE***
I started it up today first thing as it had been sitting for a little over 24 hours, started up on the first try RPMS shoot up to 1200 or so but the car sounded just a little funny like it wasn't getting enough air, or fuel. But I didn't really smell any fuel, and I'm 99% sure it's not fuel related I'll tell why in a second. Ok so I take out the key start it up again, the first time I started it I only let it run for 5 seconds, the second time it started it stalled. RPMs shot up then it tried to stay on but it stalled. Third time same thing, fourth time it did stay on. So I was like hmmm. I know it's not the MAF, so I'm pretty sure it's the IACV. Now here's the deal after the fourth try, it started up perfectly each and everytime RPMS shoot up to a nice 1400-1500 then gradually came down as the car warmed up. When the car is warm it starts up each and everytime no problem which is why I'm almost positive it's not fuel related because it would then obviously be much more consistent. I'm pretty sure it's not the MAF because I've unplugged it and it started up the same.
I also adjusted the the screw for the TB, the one that has a nut attached to it. I also sprayed some carb cleaner, and silicone cleaner on the throttle linkage. My only guess now is the IACV but I need your guys input. Since this ONLY happens first thing in the morning or afternoon, or when I first start it after it's been sitting a while it leads me to believe the IACV is sticking. Can the IACV ONLY stick the first time the car is being started and not stick for the remainder of the day? Because again once it starts up and has been running it has 0 problems.
I started it up today first thing as it had been sitting for a little over 24 hours, started up on the first try RPMS shoot up to 1200 or so but the car sounded just a little funny like it wasn't getting enough air, or fuel. But I didn't really smell any fuel, and I'm 99% sure it's not fuel related I'll tell why in a second. Ok so I take out the key start it up again, the first time I started it I only let it run for 5 seconds, the second time it started it stalled. RPMs shot up then it tried to stay on but it stalled. Third time same thing, fourth time it did stay on. So I was like hmmm. I know it's not the MAF, so I'm pretty sure it's the IACV. Now here's the deal after the fourth try, it started up perfectly each and everytime RPMS shoot up to a nice 1400-1500 then gradually came down as the car warmed up. When the car is warm it starts up each and everytime no problem which is why I'm almost positive it's not fuel related because it would then obviously be much more consistent. I'm pretty sure it's not the MAF because I've unplugged it and it started up the same.
I also adjusted the the screw for the TB, the one that has a nut attached to it. I also sprayed some carb cleaner, and silicone cleaner on the throttle linkage. My only guess now is the IACV but I need your guys input. Since this ONLY happens first thing in the morning or afternoon, or when I first start it after it's been sitting a while it leads me to believe the IACV is sticking. Can the IACV ONLY stick the first time the car is being started and not stick for the remainder of the day? Because again once it starts up and has been running it has 0 problems.
10-13-2005, 07:37 PM
#15
Originally Posted by Shadow
Sounds like the IACV. If it's cold, it can stick. So that would make sense that it only happens when you're first starting the car for the day, it's part of the reason there are coolant lines to the TB. On my wife's Integra, we removed the coolant lines to the TB to run them to the turbo, and that caused terrible cold start issues similar to what you're experiencing, but worse since the IACV never warmed up. It would fluctuate at idle, you would smell fuel, and so on. Ran the coolant lines back to the TB, problem solved.
I would definitely check the IACV.
I would definitely check the IACV.
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