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I think there might be…but it probably requires taking it off… All it does is allow small amounts of idle air into the manifold when the throttle is closed. Typically a plunger that opens when voltage is applied. When you take it off is usually when you will see oil and crud, so generally they just need cleaning.
Replace your spark plugs, wires, distributor rotor and cap if you haven’t already. I think if those components are old, they could be putting excess strain on the igniter.. and ^ check that voltage as well.
Good luck
Replace your spark plugs, wires, distributor rotor and cap if you haven’t already. I think if those components are old, they could be putting excess strain on the igniter.. and ^ check that voltage as well.
Good luck
The fact that it dies when you lift your foot off the gas tells me that the idle air control valve is not functioning properly… Is it part of the throttle body?
Also, have you checked compression in all the cylinders? Have you checked the fuel pressure? Hearing the pump may not be sufficient…Hope that helps!
The fact that it dies when you lift your foot off the gas tells me that the idle air control valve is not functioning properly… Is it part of the throttle body?
Also, have you checked compression in all the cylinders? Have you checked the fuel pressure? Hearing the pump may not be sufficient…Hope that helps!
To check the vacuum, unhook the brake booster vacuum hose from the CHECK VALVE (on or inside the hose between manifold and booster) with engine off, and hook it up to your gauge (don’t want to suck anything in there inadvertently). You should get a steady reading (might bounce +-2 psi B/C of age and worn valve guides. Adding gas will make it drop, and releasing gas should make it pop up high for a second and then get back to normal (15-18 psi i believe). Here are some suggestions for diagnosis:
http://www.gregsengine.com/using-a-vacuum-gauge.html
http://www.mysandman.com.au/forums/showthread.php/5340-Vacuum-Gauge-Engine-Diagnosis-ChartI use a hand vacuum pump, the type you use for bleeding the brakes, and it works like a charm. This is also a much easier method for testing back pressure (clogged catalyst 🙁 ), in which case the vacuum would keep dropping as you keep the throttle open. This would’ve saved you the effort of taking it off 🙁
Oh well.. next time 🙂 … I mean hopefully not…
To check the vacuum, unhook the brake booster vacuum hose from the CHECK VALVE (on or inside the hose between manifold and booster) with engine off, and hook it up to your gauge (don’t want to suck anything in there inadvertently). You should get a steady reading (might bounce +-2 psi B/C of age and worn valve guides. Adding gas will make it drop, and releasing gas should make it pop up high for a second and then get back to normal (15-18 psi i believe). Here are some suggestions for diagnosis:
http://www.gregsengine.com/using-a-vacuum-gauge.html
http://www.mysandman.com.au/forums/showthread.php/5340-Vacuum-Gauge-Engine-Diagnosis-ChartI use a hand vacuum pump, the type you use for bleeding the brakes, and it works like a charm. This is also a much easier method for testing back pressure (clogged catalyst 🙁 ), in which case the vacuum would keep dropping as you keep the throttle open. This would’ve saved you the effort of taking it off 🙁
Oh well.. next time 🙂 … I mean hopefully not…
Thank you! I’m glad its not a loose part from the engine! It didn’t look like anything that should belong in there so I’m glad I asked.
Wish me luck checking the head for major cracks today 🙂
Thank you! I’m glad its not a loose part from the engine! It didn’t look like anything that should belong in there so I’m glad I asked.
Wish me luck checking the head for major cracks today 🙂
You are on the right track, and meanwhile are getting a lot maintenance done :). Did you replace the fuel filter? And you can also check the injectors for dirt/clogging visually. But first i would look at the TPS, did you measure the operational range of the sensor to make sure it goes up smooth and doesn’t jump at some point?
How about intake air Temp (IAT) sensor? if you can swap with a working one to see if it helps id try that. Do you have the stock airbox or CAI? Think about what changed right before this started.. even season wise.. if you have a CAI, was this the first winter with it etc…
Do you have an EGR on that motor? Can you check engine vacuum? the leak could seal a little after warming up, hence the result.. Could be other possibilities, but lets start with that
You are on the right track, and meanwhile are getting a lot maintenance done :). Did you replace the fuel filter? And you can also check the injectors for dirt/clogging visually. But first i would look at the TPS, did you measure the operational range of the sensor to make sure it goes up smooth and doesn’t jump at some point?
How about intake air Temp (IAT) sensor? if you can swap with a working one to see if it helps id try that. Do you have the stock airbox or CAI? Think about what changed right before this started.. even season wise.. if you have a CAI, was this the first winter with it etc…
Do you have an EGR on that motor? Can you check engine vacuum? the leak could seal a little after warming up, hence the result.. Could be other possibilities, but lets start with that