Stalls, won't hold idle, need help. Searched.
11-28-11, 12:33 AM
#1
Stalls, won't hold idle, need help. Searched.
Alright, i've been searching the forum and google for a few weeks now trying to solve this myself, but i'm at my wits end. Hopefully someone can give me some insight into my problem.
It started a few weeks ago when I had a stuck injector and the motor was constantly flooding. I thought it might be bad plugs or wires etc, so I did a tune-up (oil, plugs, wires, etc). I finally found some old NA injectors I had lying around and sent them off to get cleaned and after installing them it cleared up my flooding issue. The car would now start on the first try instead of pulling the egi fuse and cranking it over.
When it had the bad injector the car would constantly stall, not hold an idle, and get less fuel mileage (around 200 miles per tank. I usually get 300-330).I thought this would go away when I fixed the injector issue, but it did not. I still had to drive the car to to work so I did everything I could to keep it running i.e. searching for gremlins.
The car when started cold will rev up to it's normal 1500 rpm's and hold there for a moment, then die. I can start it up again, but it will do the same thing. If I hold the gas in and let it warm up a bit it will idle, but be bouncing from 1k to 1.5k (I set it high to help it from dying at lights). The car will also operate OK with partial throttle, but will then sort of lag or feel like someone put 300 lbs in the back until I give it more throttle. Basically, if I am accelerating I am ok. If I am trying hold a speed, say on the freeway, it will occasionally feel as if I am losing power. The car will also shudder while under acceleration, and not with my foot off the gas.
The tps is set up correctly and is only a few years old ( yes, i shelled out for a brand new one a few years back. ugh). The timing is spot on and set per the FSM. The injectors have just come back from service. Just cleaned the air filter. New NGK plugs as of today. I have new sparkplug wires, but I think they might be defective. I got cheap ones instead of NGK wires like normal. Also, replaced all the fuel lines past the fuel filter. I also did a block test (those things with the blue liquid) and it did not change color. I did it to a car with blown head gasket and it changed extremely fast.
What i'm thinking is that there may be a substantial vacuum leak, but when taking off the upper intake manifold to replace the injectors I did not see anything that seemed to be broken. The hoses were pliable and not brittle. I bought all new vacuum lines to replace them all the other day, but was given the wrong size.
From searching the last few weeks i've seen others say that I could be TPS, timing, plugs, wires, bad compression, BAC, and etc.
I do have a compression tester, but haven't gotten around to testing it yet.
Sorry for the wall of text. I'm trying to put as much info as possible to help with a diagnosis.
Thanks
It started a few weeks ago when I had a stuck injector and the motor was constantly flooding. I thought it might be bad plugs or wires etc, so I did a tune-up (oil, plugs, wires, etc). I finally found some old NA injectors I had lying around and sent them off to get cleaned and after installing them it cleared up my flooding issue. The car would now start on the first try instead of pulling the egi fuse and cranking it over.
When it had the bad injector the car would constantly stall, not hold an idle, and get less fuel mileage (around 200 miles per tank. I usually get 300-330).I thought this would go away when I fixed the injector issue, but it did not. I still had to drive the car to to work so I did everything I could to keep it running i.e. searching for gremlins.
The car when started cold will rev up to it's normal 1500 rpm's and hold there for a moment, then die. I can start it up again, but it will do the same thing. If I hold the gas in and let it warm up a bit it will idle, but be bouncing from 1k to 1.5k (I set it high to help it from dying at lights). The car will also operate OK with partial throttle, but will then sort of lag or feel like someone put 300 lbs in the back until I give it more throttle. Basically, if I am accelerating I am ok. If I am trying hold a speed, say on the freeway, it will occasionally feel as if I am losing power. The car will also shudder while under acceleration, and not with my foot off the gas.
The tps is set up correctly and is only a few years old ( yes, i shelled out for a brand new one a few years back. ugh). The timing is spot on and set per the FSM. The injectors have just come back from service. Just cleaned the air filter. New NGK plugs as of today. I have new sparkplug wires, but I think they might be defective. I got cheap ones instead of NGK wires like normal. Also, replaced all the fuel lines past the fuel filter. I also did a block test (those things with the blue liquid) and it did not change color. I did it to a car with blown head gasket and it changed extremely fast.
What i'm thinking is that there may be a substantial vacuum leak, but when taking off the upper intake manifold to replace the injectors I did not see anything that seemed to be broken. The hoses were pliable and not brittle. I bought all new vacuum lines to replace them all the other day, but was given the wrong size.
From searching the last few weeks i've seen others say that I could be TPS, timing, plugs, wires, bad compression, BAC, and etc. I do have a compression tester, but haven't gotten around to testing it yet.
Sorry for the wall of text. I'm trying to put as much info as possible to help with a diagnosis.
Thanks
11-28-11, 12:58 PM
#3
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I'd check for a vacuum leak around the lower intake manifold. Did you throughly remove the old gasket and install a new one when you pulled the intake off to get to the fuel injectors? I had a similar problem and found to be a vacuum leak at the gasket. If you have one, it's obvious when you spray carb. cleaner around the area while idling. The seal there has to be perfect.
11-29-11, 01:36 PM
#5
Did a compression test, but I might have done it wrong. I hooked it up and left the release valve in and got 55psi on each pulse. Either I have amazing compression or I did it wrong. I'll look into it before I go to sleep.
I sprayed carb cleaner around the whole engine and the only time it revved up (more than normal. the idle is still pulsing) was when I sprayed a bit into the air filter and the egr.
I also unplugged the BAC and it did nothing.
On the bright side I did find a pinhole leak on a heater hose while I was searching.
I sprayed carb cleaner around the whole engine and the only time it revved up (more than normal. the idle is still pulsing) was when I sprayed a bit into the air filter and the egr.
I also unplugged the BAC and it did nothing.
On the bright side I did find a pinhole leak on a heater hose while I was searching.
11-29-11, 05:22 PM
#6
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You said you set the tps, but might want to check that again. Did you set it after you reinstalled the UIM? Also check your throttle cable and make sure all of the vacuum lines are connected (especially behind the UIM).
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12-01-11, 07:36 PM
#14
Out of curiosity, why are you replacing the EGR valve? If it's not working, that's one thing, but if it's just the gasket blown out, replace the gasket.
I'll even stop the question before you ask.
Get a mityvac. Find the vacuum line going to the egr valve and apply vacuum to the egr valve. Does it hold vacuum? If so, then move on to the next test. If not, replace.
Start the car. Let it warm up fully. At idle, apply vacuum to the egr valve. Around 6" should open it fully. If the engine stumbles or dies, then the EGR valve is working properly and does not need to be replaced.
A mityvac is a great tool to have around, especially if you're going to be working on your car now.
I'll even stop the question before you ask.
Get a mityvac. Find the vacuum line going to the egr valve and apply vacuum to the egr valve. Does it hold vacuum? If so, then move on to the next test. If not, replace.
Start the car. Let it warm up fully. At idle, apply vacuum to the egr valve. Around 6" should open it fully. If the engine stumbles or dies, then the EGR valve is working properly and does not need to be replaced.
A mityvac is a great tool to have around, especially if you're going to be working on your car now.
12-02-11, 01:40 PM
#16
Out of curiosity, why are you replacing the EGR valve? If it's not working, that's one thing, but if it's just the gasket blown out, replace the gasket.
I'll even stop the question before you ask.
Get a mityvac. Find the vacuum line going to the egr valve and apply vacuum to the egr valve. Does it hold vacuum? If so, then move on to the next test. If not, replace.
Start the car. Let it warm up fully. At idle, apply vacuum to the egr valve. Around 6" should open it fully. If the engine stumbles or dies, then the EGR valve is working properly and does not need to be replaced.
A mityvac is a great tool to have around, especially if you're going to be working on your car now.
I'll even stop the question before you ask.
Get a mityvac. Find the vacuum line going to the egr valve and apply vacuum to the egr valve. Does it hold vacuum? If so, then move on to the next test. If not, replace.
Start the car. Let it warm up fully. At idle, apply vacuum to the egr valve. Around 6" should open it fully. If the engine stumbles or dies, then the EGR valve is working properly and does not need to be replaced.
A mityvac is a great tool to have around, especially if you're going to be working on your car now.
@Matt I'll probably just come get it since I wanna check out your build anyways.
12-05-11, 04:14 PM
#19
Not yet. We did find a fuel leak on the line coming from the fuel filter to the top of the block, but after fixing it we did not notice any change. At least that's one less thing.
I got out my multi-meter and checked the BAC and the AFM and they checked out OK. I applied 12v to the BAC and it made a clicking noise as specified in the FSM so i'm guessing it's working.
I cleaned up the contact on the CAS and restabbed it a few times to no avail. I'm assuming there is a major vacuum leak that I cannot see and am going to have to change all the vacuum lines. I got sick over the weekend and was not able to do much troubleshooting aside from that.
I got out my multi-meter and checked the BAC and the AFM and they checked out OK. I applied 12v to the BAC and it made a clicking noise as specified in the FSM so i'm guessing it's working.
I cleaned up the contact on the CAS and restabbed it a few times to no avail. I'm assuming there is a major vacuum leak that I cannot see and am going to have to change all the vacuum lines. I got sick over the weekend and was not able to do much troubleshooting aside from that.
12-05-11, 07:25 PM
#20
Noticed last night when I fixed the fuel line that the pressure seemed lower than normal. I've pulled off a fuel line even after depressurizing it and the pressure was still rather high. As in "explodes everywhere". When I pulled the line off last night it was more like "dribble". Could the fuel filter possibly be due for a change? The car stumbles and chokes unless you floor it, then it's ok'ish.
12-11-11, 01:42 AM
#24
Changed the fuel filter. I did a little bit, but did not fix the issue. Still dies when it is cold and will surge between 750-1000 rpms when warm. Feels really weak and will still die at stoplights. The idle is turned as far as it can go, the CAS has been restabbed and the timing is right, TPS was reset as it was off just a hair, no fuel leaks, and just that air leak on the EGR. I'm going to swap a known good one in and a new gasket and see what that does.
