1994 Ford Thunderbird LX 3.8L EFI
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1994 Ford Thunderbird LX 3.8L EFI
Replaced distributer cap, wires, plugs, rotor, distributer itself actually (yep from un-related problem) IAC, air filter, coilk, cleaned intake valve, replaced a couple of semi-obvious worn vacume hoses, and it still "sputters" when in gear at a stop light with the foot on the brake?
What the heck could it be if all the above has been replaced? At the shop on a diagnostics test ($90) it said IACV. OK, replaced simply myself, and now the same problem??? The car will almost die at a stop light, but yet it only has 57k original miles on it??? (former friend of the families vehicle). Would appreciate some straight experience talk on this vice "buy another wasteful $20 manual that doesn't answer the basic questions."...tired of the crickets.
What the heck could it be if all the above has been replaced? At the shop on a diagnostics test ($90) it said IACV. OK, replaced simply myself, and now the same problem??? The car will almost die at a stop light, but yet it only has 57k original miles on it??? (former friend of the families vehicle). Would appreciate some straight experience talk on this vice "buy another wasteful $20 manual that doesn't answer the basic questions."...tired of the crickets.
#2
Ford has a poor track record with EGR valves.......
If the valve doesnt seal when commanded to close, It leaks vacuum. This can vary in intensity from a Mild stutter at idle, to a no start situation.
Pop it off..... Clean out the ports in the valve itself, and the intake. The "Blow into it test" can be used to check for leaks after youve cleaned it out. Bolt it back up and try it.....Cheap and easy, and you can do it yourself without spending Your Green...
If the valve doesnt seal when commanded to close, It leaks vacuum. This can vary in intensity from a Mild stutter at idle, to a no start situation.
Pop it off..... Clean out the ports in the valve itself, and the intake. The "Blow into it test" can be used to check for leaks after youve cleaned it out. Bolt it back up and try it.....Cheap and easy, and you can do it yourself without spending Your Green...

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Didn't get to it unfortunatelyt due to some other pressing projects. Popped the hood and sort of took a look for it. Is it that round vacumn pump looking thing on the firewall side of the throttle body just below the IAC?
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This tells you all about it "para nada"
AutoZone.com | Vehicle Selection - Year
In regards to the IAC the code for it is telling you the little jobby isn't doing it job of regulating the idle air. The problem could be in the vacuum source to the valve or the circuitry to the IAC.
AutoZone.com | Vehicle Selection - Year
In regards to the IAC the code for it is telling you the little jobby isn't doing it job of regulating the idle air. The problem could be in the vacuum source to the valve or the circuitry to the IAC.
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Well I just finished taking it all apart. I cleaned up the round vacume (EGR?) looking thing, and I did a little suction test just using my mouth and it seems to function okay. I'm going to run up the road and just buy a new one since I have it all apart (exhaust line was a biotch to get off).
Aside from that where would the vacume "source" come from in terms of checking next. Not that the problem is critical, but it is extremely annoying and now I have my sleeves rolled up willing to tackle it....depsite the slight drizzle happening outside.
Aside from that where would the vacume "source" come from in terms of checking next. Not that the problem is critical, but it is extremely annoying and now I have my sleeves rolled up willing to tackle it....depsite the slight drizzle happening outside.
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does the engine actually sputter or is it just trying to die at idle, few things you might try is if its only when you apply the brakes, are you sure the booster isnt leaking when they leak you can usually hear them but it can cause a large vacum leak , if you pinch off the vacum line to the booster and see if you notice any difference, dont recomend driving the car with the vacum line pinched off as your brakes will not be to good. the other thing to try at idle in park with all accessories off and the engine warmed up disconnect the idle air bypass valve and see if the engine stays running or dies if it dies you may need to clean the throttle plate. actually kind of doubt the problem is related to a vacum leak.
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Took the EGR valve off and cleaned. When using my mouth on it, it seems to function well. Put a vacume pump on it and looked to see if the valve worked and it did. So I put tit back on and the same problem is there. I disconnected the vacukme frim it while idling and felt for vacume. There only a barely noticeable bit of vacume? and the idling never changed. Disconnected the plug on the unit nearby where the vacume lines originate and nothing changed either? It's a annoying problem as the car continually acts like it wants to die at a traffic light including when I put it in neutral. So I guess i need to work backwards from the EGR? But where?
I will also check the boost pump vacume on the next go around. Raining & cold today.
I will also check the boost pump vacume on the next go around. Raining & cold today.
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Continuing problem. I notice lately that when I first start it the motor suddenly races fast. Sometimes when I stop and put in park, the motor will once again race high RPM before settling down? Sitting at a light in gear, foot on brake, it will chug or sputter. At the light with foot on brake, move it to neutral, it will idle okay though not exactly perfect, but snmoother? Not sure where or what to look at from here. Again not a dire circumstance, but extremely annoying.
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On the big round power assist that the brake master cylinder mounts to, there's a fairly large vacume hose attached. It looks like it can just be pulled out of it's rubber grommet. Is that true or no don't just tug it out I'll screw it up?
As mentioned in the previous post my messing around with hoses has somehow coincided with the car when first started up it races at unusually high RPM. Even when sitting in neutral it will race up, then come back down, race up come back down after it's warmed up. All I really did was twist that vacume hose a little I mentiond on the power assist trying to ascertain if it just comes out? Almost like doing that upset the balance of vacume somehow.
Could it be the "NEW" IAC valve is getting false signals as well?
As mentioned in the previous post my messing around with hoses has somehow coincided with the car when first started up it races at unusually high RPM. Even when sitting in neutral it will race up, then come back down, race up come back down after it's warmed up. All I really did was twist that vacume hose a little I mentiond on the power assist trying to ascertain if it just comes out? Almost like doing that upset the balance of vacume somehow.
Could it be the "NEW" IAC valve is getting false signals as well?
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it should pull out of the rubber grommet but if the grommet gets damaged wich occasionaly happens you can buy just a new grommet for the booster.
if you cant find any vacum leaks would check codes maybe check the tps you can check it with a voltmeter probed into the middle wire by slowly moving the throttle with the key on to see if the voltage ever drops or is erratic. as it could cause the iac valve to vary the idle speed.
just curious what type of plug wires did you put on the vehicle are they stock or atleast stock replacement?
if you cant find any vacum leaks would check codes maybe check the tps you can check it with a voltmeter probed into the middle wire by slowly moving the throttle with the key on to see if the voltage ever drops or is erratic. as it could cause the iac valve to vary the idle speed.
just curious what type of plug wires did you put on the vehicle are they stock or atleast stock replacement?
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Plug wires were stock replacements gotten from Advance Auto. Didn't really need to replace them and actually done that last summer. The problem I'm experiencing now though worse than before, has been there since I bought it in 2004. I had since, done all the basic replacements including serpentine, anti-freeze, and tranny fluid. The distribor/shaft was replaced last year with a new one in the shop. It's been on a scanner that only showed IAC code hence my replacing that with no change. Then like I said it has gotten a little worse with the racing up stuff.
I've been traveling and busy lately and have set it aside for th eitme being. But as soon as I re-focus on it i will definitely try the TPS wire read suggestion and see what I get.
I've been traveling and busy lately and have set it aside for th eitme being. But as soon as I re-focus on it i will definitely try the TPS wire read suggestion and see what I get.