Cold starts take long, every start after fires right up (350TPI)
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Re: Cold starts take long, every start after fires right up (350TPI)
Sorry for the delay getting back with you. Ive been busy at work today. I agree you need to check for vacuum leaks. The best thing to use is aerosol brake cleaner. Its cheap and non flamable and it will reveal a leak quite well. The difference in the TB gasket looks strange I know but if you look closely, they really do seal just the same. The one has the triangle opening where the other just has an open area. You cant put the gasket on backwards because it only goes one way. If your IAC was blocked off, the car wouldnt idle.
I really wish you had access to a scanner right now. Integrator and Block Learn will show you how lean you are running. You do have a volt meter though. Use it to monitor O2 voltage by disconnecting O2 sensor and attaching volt meter + lead to sensor side of connector. Youll see the voltage rise or fall with fuel mixture. In this mode, BLM and integrator will go neutral with the sensor disconnected. The voltage you see is the uncorrected fuel air ratio. This test works well for finding lean or rich conditions.
Another thing to look at, did you reset the fuel adaptives after changing injectors? Reset adaptives by disconnecting batt- for 30 seconds. Stealth mentioned IAC setting. You cant actually set IAC or TPS since they are both non adjustable. You can however set base idle. This can have a significant effect on fuel correction. Your manual should have instructions for setting idle.
In case your manual doesnt have the procedure. Here's a quick run through. In order to set base idle, you first need to access throttle stop screw. If the plug is not already out, you need to remove it by piercing it with a sharp awl or drill. Then pop it out by carefully prying it. Set base idle in the following manner: jump terminals A & B of the ALDL, disconnect the timing connector, turn the key on and wait for 45 seconds, disconnect the IAC, then remove jumper from ALDL. Start the engine and allow it to go into closed loop, set idle to 450rpm. Turn off key, reconnect timing connector, reconnect IAC, reset ECM by disconnecting batt- for 30 seconds.
I really wish you had access to a scanner right now. Integrator and Block Learn will show you how lean you are running. You do have a volt meter though. Use it to monitor O2 voltage by disconnecting O2 sensor and attaching volt meter + lead to sensor side of connector. Youll see the voltage rise or fall with fuel mixture. In this mode, BLM and integrator will go neutral with the sensor disconnected. The voltage you see is the uncorrected fuel air ratio. This test works well for finding lean or rich conditions.
Another thing to look at, did you reset the fuel adaptives after changing injectors? Reset adaptives by disconnecting batt- for 30 seconds. Stealth mentioned IAC setting. You cant actually set IAC or TPS since they are both non adjustable. You can however set base idle. This can have a significant effect on fuel correction. Your manual should have instructions for setting idle.
In case your manual doesnt have the procedure. Here's a quick run through. In order to set base idle, you first need to access throttle stop screw. If the plug is not already out, you need to remove it by piercing it with a sharp awl or drill. Then pop it out by carefully prying it. Set base idle in the following manner: jump terminals A & B of the ALDL, disconnect the timing connector, turn the key on and wait for 45 seconds, disconnect the IAC, then remove jumper from ALDL. Start the engine and allow it to go into closed loop, set idle to 450rpm. Turn off key, reconnect timing connector, reconnect IAC, reset ECM by disconnecting batt- for 30 seconds.
Last edited by tagta3; Oct 16, 2010 at 08:31 AM.
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From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: Cold starts take long, every start after fires right up (350TPI)
Setting base idle will not affect base timing. TPS may be changed and should be checked after idle is set. Remember, intake air leaks(vacuum leaks) are your main concern here. I think you must be getting unmetered air to cause a lean condition with the new injectors. Besure to check your O2 sensor if no leaks are found.
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Joined: Apr 2010
Posts: 4,337
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From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: Cold starts take long, every start after fires right up (350TPI)
I never thought to ask. Is your car MAF or speed density? If its MAF, be sure that your air duct is not leaking between the TB and the MAF. Be sure that your PCV system is sealed as well.
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Re: Cold starts take long, every start after fires right up (350TPI)
Setting base idle will not affect base timing. TPS may be changed and should be checked after idle is set. Remember, intake air leaks(vacuum leaks) are your main concern here. I think you must be getting unmetered air to cause a lean condition with the new injectors. Besure to check your O2 sensor if no leaks are found.
Last edited by tagta3; Oct 17, 2010 at 02:08 PM.
Supreme Member
Joined: Apr 2010
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From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: Cold starts take long, every start after fires right up (350TPI)
Youll have a higher idle with a manual trans. Even at idle, the TC places a small load on the engine. Im glad your engine is running better. Good news. If you ever get tired of shifting gears, Id be glad to take the T56 off your hands. Lol. How difficult was the swap for you?
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Re: Cold starts take long, every start after fires right up (350TPI)
Youll have a higher idle with a manual trans. Even at idle, the TC places a small load on the engine. Im glad your engine is running better. Good news. If you ever get tired of shifting gears, Id be glad to take the T56 off your hands. Lol. How difficult was the swap for you?
Last edited by tagta3; Oct 18, 2010 at 07:30 AM.
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From: Crestview, Fl
Car: 87 GTA
Engine: tpi 350
Transmission: 700r4
Re: Cold starts take long, every start after fires right up (350TPI)
I said Check/adjust.
That is a little misleading, I agree. You can check and adjust the TPS. You can't adjust the IAC. WHat I should have said was Check/adjust the minimum air setting and the TPS.
edit: By the way, glad you got it fixed.
That is a little misleading, I agree. You can check and adjust the TPS. You can't adjust the IAC. WHat I should have said was Check/adjust the minimum air setting and the TPS.
edit: By the way, glad you got it fixed.
Last edited by stealth908; Oct 18, 2010 at 01:31 PM.
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Joined: Apr 2010
Posts: 4,337
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From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: Cold starts take long, every start after fires right up (350TPI)
Witha manual trans you can idle the motor wherever its comfortable for you. With an auto, the TC limits idle speed. As engine speed increases above 600 with the OE TC stall point of about 1,800RPM, the pull on the car's drivetrain becomes uncomfortable. And shifting from park to reverse becomes a little unsettling. With a manual trns this is a non issue. For a stock cam TPI, 600 is about right. If you ran a setup like mine, you'd probably want more like 800-900.
Supreme Member
Joined: Apr 2010
Posts: 4,337
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From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: Cold starts take long, every start after fires right up (350TPI)
500-1000 rpm is a little low for power production anyway. I wouldnt expect even a TPI to start pulling much below 1,200.
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Re: Cold starts take long, every start after fires right up (350TPI)
While I agree with you, it felt different (more torquey between 500-1000rpm) before the injector swap, but then again even though they are 22lbs/hr, they probably behave differently for a given pulse width when compared to the original Mutel's. I would think they would behave better because the Bosch III's really atomize...Everyone thanks for your help and support! It was greatly appreciated.
Last edited by tagta3; Oct 21, 2010 at 09:04 AM.
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Joined: Jan 2004
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From: So. Ohio
Car: 88 Camaro
Engine: L98 350
Transmission: 700r4
Re: Cold starts take long, every start after fires right up (350TPI)
Glad to hear you've got it straightened out. One good suggestion is to buy a scanner. With this you can scan the IAC counts and tell if there is a vacuum leak that is causing problems. With a high idle and counts down to zero that's a sure sign of a leak. Useful for many other things too. I have an old Auto Xray XP240 that I use. Pulls codes, does a scan and freeze of sensors, memory for later recall, and does a real time readout of the various sensors. Probably have to find a used one these days, be pretty cheap though. Don't spend a lot of money on what they call code readers, no real help on the OBD1 cars as you can pull codes with a paperclip. This is the scanner I use, probably others out there just as good:
http://www.fuelinjection.com/autoxray.html
http://www.fuelinjection.com/autoxray.html
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Re: Cold starts take long, every start after fires right up (350TPI)
That's it I'm buying a scanner. I was thinking about the moates XtremeALDL for $80... http://www.moates.net/aldu1-and-cabl....html?cPath=64
Can someone recommend an affordable hand-held scanner for me? So far ASEdoc recommended a Snap-On MT2500 scanner going for over $400 on ebay. tom3 recommends Auto Xray XP240, not sure where to buy them though? Any more recommendations?
Can I use Equus 3120 or 3140 for live data?
Can someone recommend an affordable hand-held scanner for me? So far ASEdoc recommended a Snap-On MT2500 scanner going for over $400 on ebay. tom3 recommends Auto Xray XP240, not sure where to buy them though? Any more recommendations?
Can I use Equus 3120 or 3140 for live data?
Last edited by tagta3; Oct 21, 2010 at 10:53 AM.
Supreme Member
Joined: Apr 2010
Posts: 4,337
Likes: 29
From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: Cold starts take long, every start after fires right up (350TPI)
The problem with the AX240 is the same problem with the MT2500. Neither has factory support as they are both discontinued. The advantage to the MT2500 is its proven durability. Thats why I recommend it so strongly. These machines have bee around since the 80s and they just dont die. The cable they use is the same cable used by the newer MODIS.
However, if youre looking for something less expensive thats not so obsolete, I would probably go with something PC based like the Xtreme ALDL. The only hardware youre buying is an interface cable. The rest of it is just software and it will allow much more flexability and upgradability. Most of the repair industry, including the OE is going PC based.
However, if youre looking for something less expensive thats not so obsolete, I would probably go with something PC based like the Xtreme ALDL. The only hardware youre buying is an interface cable. The rest of it is just software and it will allow much more flexability and upgradability. Most of the repair industry, including the OE is going PC based.
Thread Starter
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Joined: Mar 2004
Posts: 69
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Re: Cold starts take long, every start after fires right up (350TPI)
The problem with the AX240 is the same problem with the MT2500. Neither has factory support as they are both discontinued. The advantage to the MT2500 is its proven durability. Thats why I recommend it so strongly. These machines have bee around since the 80s and they just dont die. The cable they use is the same cable used by the newer MODIS.
However, if youre looking for something less expensive thats not so obsolete, I would probably go with something PC based like the Xtreme ALDL. The only hardware youre buying is an interface cable. The rest of it is just software and it will allow much more flexability and upgradability. Most of the repair industry, including the OE is going PC based.
However, if youre looking for something less expensive thats not so obsolete, I would probably go with something PC based like the Xtreme ALDL. The only hardware youre buying is an interface cable. The rest of it is just software and it will allow much more flexability and upgradability. Most of the repair industry, including the OE is going PC based.
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From: Menifee, California
Car: 1988 Pontiac Trans Am GTA
Engine: L98 TPI 5.7L 350
Transmission: 700R4 Automatic
Re: Cold starts take long, every start after fires right up (350TPI)
Sorry for the delay getting back with you. Ive been busy at work today. I agree you need to check for vacuum leaks. The best thing to use is aerosol brake cleaner. Its cheap and non flamable and it will reveal a leak quite well. The difference in the TB gasket looks strange I know but if you look closely, they really do seal just the same. The one has the triangle opening where the other just has an open area. You cant put the gasket on backwards because it only goes one way. If your IAC was blocked off, the car wouldnt idle.
I really wish you had access to a scanner right now. Integrator and Block Learn will show you how lean you are running. You do have a volt meter though. Use it to monitor O2 voltage by disconnecting O2 sensor and attaching volt meter + lead to sensor side of connector. Youll see the voltage rise or fall with fuel mixture. In this mode, BLM and integrator will go neutral with the sensor disconnected. The voltage you see is the uncorrected fuel air ratio. This test works well for finding lean or rich conditions.
Another thing to look at, did you reset the fuel adaptives after changing injectors? Reset adaptives by disconnecting batt- for 30 seconds. Stealth mentioned IAC setting. You cant actually set IAC or TPS since they are both non adjustable. You can however set base idle. This can have a significant effect on fuel correction. Your manual should have instructions for setting idle.
In case your manual doesnt have the procedure. Here's a quick run through. In order to set base idle, you first need to access throttle stop screw. If the plug is not already out, you need to remove it by piercing it with a sharp awl or drill. Then pop it out by carefully prying it. Set base idle in the following manner: jump terminals A & B of the ALDL, disconnect the timing connector, turn the key on and wait for 45 seconds, disconnect the IAC, then remove jumper from ALDL. Start the engine and allow it to go into closed loop, set idle to 450rpm. Turn off key, reconnect timing connector, reconnect IAC, reset ECM by disconnecting batt- for 30 seconds.
I really wish you had access to a scanner right now. Integrator and Block Learn will show you how lean you are running. You do have a volt meter though. Use it to monitor O2 voltage by disconnecting O2 sensor and attaching volt meter + lead to sensor side of connector. Youll see the voltage rise or fall with fuel mixture. In this mode, BLM and integrator will go neutral with the sensor disconnected. The voltage you see is the uncorrected fuel air ratio. This test works well for finding lean or rich conditions.
Another thing to look at, did you reset the fuel adaptives after changing injectors? Reset adaptives by disconnecting batt- for 30 seconds. Stealth mentioned IAC setting. You cant actually set IAC or TPS since they are both non adjustable. You can however set base idle. This can have a significant effect on fuel correction. Your manual should have instructions for setting idle.
In case your manual doesnt have the procedure. Here's a quick run through. In order to set base idle, you first need to access throttle stop screw. If the plug is not already out, you need to remove it by piercing it with a sharp awl or drill. Then pop it out by carefully prying it. Set base idle in the following manner: jump terminals A & B of the ALDL, disconnect the timing connector, turn the key on and wait for 45 seconds, disconnect the IAC, then remove jumper from ALDL. Start the engine and allow it to go into closed loop, set idle to 450rpm. Turn off key, reconnect timing connector, reconnect IAC, reset ECM by disconnecting batt- for 30 seconds.
Thread Starter
Junior Member
Joined: Mar 2004
Posts: 69
Likes: 0
Re: Cold starts take long, every start after fires right up (350TPI)
The problem with the AX240 is the same problem with the MT2500. Neither has factory support as they are both discontinued. The advantage to the MT2500 is its proven durability. Thats why I recommend it so strongly. These machines have bee around since the 80s and they just dont die. The cable they use is the same cable used by the newer MODIS.
However, if youre looking for something less expensive thats not so obsolete, I would probably go with something PC based like the Xtreme ALDL. The only hardware youre buying is an interface cable. The rest of it is just software and it will allow much more flexability and upgradability. Most of the repair industry, including the OE is going PC based.
However, if youre looking for something less expensive thats not so obsolete, I would probably go with something PC based like the Xtreme ALDL. The only hardware youre buying is an interface cable. The rest of it is just software and it will allow much more flexability and upgradability. Most of the repair industry, including the OE is going PC based.
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From: Kansas City
Car: LT4 C4, LT1 CE, 95' Dyno Air
Transmission: ZF S6-40, 4L60E, sprockets
Axle/Gears: 3.45, 3.07
Re: Cold starts take long, every start after fires right up (350TPI)
Almost sounds like the FPR vacuum line is temporarily collapsing?
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Re: Cold starts take long, every start after fires right up (350TPI)
OK guys, I could use your opinions again please. The hesitation is still there so I decided to do the following. With the car in neutral when I blip the throttle you can actually hear and see the engine hesitate for a second everyt ime I rev, but just the initial part of the rev.
I wanted to make sure that every injector was working while idling, so I unplugged each injector while it was running, one at a time, and the one that did not change the idle or exhaust note in any way would be the one malfunctioning. All the injectors checked out fine. Is that a valid way to check? (I don't think they should have a problem because the car has power after 1000rpm).
While I was doing this test I noticed a very slight ticking on the passenger side and everytime I rev it there is a single louder tick sound after the rpm's drop, it does it everytime. Why is there always just one louder tick after the rpm drops after I rev, is that a spark arc discharging somewhere after spark energy accumulates after the rev? I think I have a spark plug wire arcing somewhere, what do you guys think? It only hesitates like I said before between 500-1000rpm or just the first blip of throttle.
I wanted to make sure that every injector was working while idling, so I unplugged each injector while it was running, one at a time, and the one that did not change the idle or exhaust note in any way would be the one malfunctioning. All the injectors checked out fine. Is that a valid way to check? (I don't think they should have a problem because the car has power after 1000rpm).
While I was doing this test I noticed a very slight ticking on the passenger side and everytime I rev it there is a single louder tick sound after the rpm's drop, it does it everytime. Why is there always just one louder tick after the rpm drops after I rev, is that a spark arc discharging somewhere after spark energy accumulates after the rev? I think I have a spark plug wire arcing somewhere, what do you guys think? It only hesitates like I said before between 500-1000rpm or just the first blip of throttle.
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From: Kansas City
Car: LT4 C4, LT1 CE, 95' Dyno Air
Transmission: ZF S6-40, 4L60E, sprockets
Axle/Gears: 3.45, 3.07
Re: Cold starts take long, every start after fires right up (350TPI)
Try misting water at the plug wires in the dark to see if you have something out of the ordinary going on with the ignition. Sounds odd maybe, but you could easily have an erronious arc.
Also, check for play in the throttle shaft where it enters the TB by the butterfly on the DS. My 87 had a hesitation like you are experiencing because of this. If you find an issure there I recommend upgrading to a newer style TB with the progressive linkage (you have to swap the cable from the pedal to TB as well); much more linear power delivery for powersliding.
Also, check for play in the throttle shaft where it enters the TB by the butterfly on the DS. My 87 had a hesitation like you are experiencing because of this. If you find an issure there I recommend upgrading to a newer style TB with the progressive linkage (you have to swap the cable from the pedal to TB as well); much more linear power delivery for powersliding.
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Re: Cold starts take long, every start after fires right up (350TPI)
Try misting water at the plug wires in the dark to see if you have something out of the ordinary going on with the ignition. Sounds odd maybe, but you could easily have an erronious arc.
Also, check for play in the throttle shaft where it enters the TB by the butterfly on the DS. My 87 had a hesitation like you are experiencing because of this. If you find an issure there I recommend upgrading to a newer style TB with the progressive linkage (you have to swap the cable from the pedal to TB as well); much more linear power delivery for powersliding.
Also, check for play in the throttle shaft where it enters the TB by the butterfly on the DS. My 87 had a hesitation like you are experiencing because of this. If you find an issure there I recommend upgrading to a newer style TB with the progressive linkage (you have to swap the cable from the pedal to TB as well); much more linear power delivery for powersliding.
Usually when a car hesitates from idle can also indicate incorrect timing. Even though it is at 6 degrees should I try playing with it. Some of my friends are telling me that 6 degrees may no longer apply with a high mileage engine (130k). The new plugs and wires, distributor cap, rotor, and msd ignition coil will be here on Monday. If replace those and there is still no change, what should my next move be? This is driving me nuts. It's like it's so simple but I just can't figure it out.
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From: Kansas City
Car: LT4 C4, LT1 CE, 95' Dyno Air
Transmission: ZF S6-40, 4L60E, sprockets
Axle/Gears: 3.45, 3.07
Re: Cold starts take long, every start after fires right up (350TPI)
Sounds like the plugs are fine.
While you are rehabing the ignition you had might as well go for a new pickup coil and ignition module.
While you are rehabing the ignition you had might as well go for a new pickup coil and ignition module.
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Re: Cold starts take long, every start after fires right up (350TPI)
Could these be causing an issue only from idle? Could a CTS (coolant temp sensor) do this only at idle?
Last edited by tagta3; Nov 6, 2010 at 05:56 PM.
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Re: Cold starts take long, every start after fires right up (350TPI)
Can anyone please help me here I'm getting desperate. I replaced the spark plugs, wires, cap, rotor, coil and it is still surging on me. To recap, say I start it from 2nd gear and the RPM is at 600 when I press the gas the car hesitates a lot until it gets to about 1000-1200rpm and clears up. This all happened after I replaced the injectors to Bosch III's. I checked the coolant temp sensor and it's reading 450ohms at about 130 degrees Fahrenheit, does that sound right? Can anyone please help me? If you want we can talk over phone too.
Last edited by tagta3; Nov 11, 2010 at 08:33 PM.
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Re: Cold starts take long, every start after fires right up (350TPI)
OK here's an update. I put the old injectors back in and the car is back to normal. I don't know why my car didn't agree with the Bosch III's but I'm glad she's back to normal.
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