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Discussion Starter #1
:8 1st time user
My MDX Touring Navy would not hot start after long or short runs. It cranks over at full, normal speed but does not fire-up. The first 3 different times approx. three months apart it took 4 to 5 tries before starting. 9/19/02 it took about 8 or 9 tries and would not respond in any way. I went back in my house to cool down and came back out ~ 6 min. later and it started right up normally.

The dealer says he doesnt have a clue and " cannot fix without it happening in front of him".
This is the 1st car with fuel injection I have owned, past were GM's, that has done this.
It remindes me of the old carburated/auto choke days.

If anyone can shed some light on this problem please post.
BAFFELED IN BUFFALO (nY)

Thanks, NICK
 

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Nick,
A while ago it was discussed that the ignition key has a security chip in it that metalic objects can interfer with such as a key chain or other keys. This is a long shot but the only thing I have ever seen in the forum that comes close to your problem.
 

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Discussion Starter #5
RAY LAKS is where I purchased my 2001 MDX and is the only dealer in the Buffalo area. Called the Acura customer service and got the same answer- fluff off! Asked to speek with an engineer and case mgr said that that was not possible.
 

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In Pilot too-

Nick, this is an issue that is present in some Pilots as well. I agree with remery in that it might be an immobilizer issue. Try to leave the key in for a few seconds and see what happens-
 

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Nick,
You're a newbie and would not be expected to know that Acura Customer Service is not the first line of defense, your dealer is. Call Ray Laks again and ask if failure of the digtial key signal to unlock the ignition could be your problem as I hypothesized in my previous post. If not, then I haven't seen anything else in this forum that approximates your experience. By the way, Tim from Hondacuraworld is a moderator in this forum and is also the Parts Manager at the Ray Laks dealership.
 

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Earlier Hondas, particularly early to mid 90's Accords, had a hot crank no start problem caused by a bad PGM-FI(main fuel) relay. They're tucked up in the dash, and on hot days, that thing gets heat soaked enough and weakens it.

I've never seen one fail on and MDX though. Seen a few on Integras, and maybe a couple on the newer TLs. But it's always a possibility.

I agree that it's more likely a problem with Imobilizer though. I won't bother posting how to diagnose the Imobi. because you'll need tools that only the dealer has. But the PGM-FI relay operation can be verified by hooking up a fuel pressure gauge to the test port and watching for pressure every time you try to crank.

Rob
 

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Main Fuel Relay

Nick,
I had the same problem with my 91 Accord EX. It would not hot start and if parked in a direction such that it would get direct rays from the sun it would also not start even if the engine was cold. In that case the sun warmed the relay enough that it wouldn't work. They replaced the main fuel relay and never again had a problem. Have to agree with RobSJ on this one.
 

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I have an idea -- next time this happens, take the key out and reverse it so that the teeth that were on the bottom are now on the top. This will change the position of the electronic chip in the key in respect to the sensor in/near the ignition switch. If it works in one position and not the other, then it's an immobilizer problem that might be as easy as giving you another key.

If THAT doesn't do it, try another key, including the valet key; if the other key works and yours is "iffy," then your key is probably bad. If different keys have the same problem, then it could be anything else in the immobilizer system, or a bad relay as RobSJ suggested, or...
 

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Discussion Starter #11
To all that responded to hot start problem. I am taking to Ray Laks friday to have the fuel pump relay changed and willl give him a printout of all of your suggestions.
My thanks to: ByeByeChrysler, remery, MG Pilot, TheRobSJ, R Stevens and frostyra

I will let you know the outcome
 

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If the ignition immobilizer is the cause, I thought the there was an "immobilizer indicator light" on the dash that would indicate the problem [this is from memory, don't look at the light because we don't have the problem].

Specifically, I thought it was supposed to flash if the ignition key didn't "register correctly" [e.g. didn't provide the requisite ID].

Additionally, I vaguely remember the following [don't hold me to this]:

** Other metal [keys, key ring, etc] could effect the operation. I think Acura actually suggested to put the key on a plastic key ring [wonder how many X owners did this? -- Not this one, you can bet on it].

** Other "immobilizer keys" can interfere with the system. I think Acura recommended not to put other immobilzer keys with the X key.

** Heck, now that I am thinking about it ... think Acura actually suggested to put X's ignition key on its very own keychain and yes, I believe that they suggested plastic.

We could start a survey of our X keychains but I can't believe that "all alone on a plastic key fob" is gonna be the big winner!!
 

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Dale, I didn't think of it either (and you and I are two of the engineers in the group!):rolleyes: (edit a couple of minutes later): The '01 manual isn't too specific, but from the schematic on p. 22-201, it looks like the immobilizer disables the fuel pump; I don't spot any connection with the starter.
 

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Well, being the "Village Idiot", I'm also allowed to be wrong.. I just went to my 2001 Service manual.. and the Immobilizer cuts off the power to the fuel pump.. so the engine will trun over.

I guess the thing to do is turn the key to the II position and wait a little while before starting and see if that helps.

Sorry for the misdirection.

Rail
 

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Soooo....

If I hear all this right:

If the MDX is working correctly but the key is the problem, then I think the dash indicator should blink to indicate that the "key is not correct" [or did I read the manual wrong?]. Ooops -- guess the "key reader circuit" could also be messed up here.

If the key is correct but the MDX is not working correctly, then sounds like the fuel pump will be disabled or not enabled [whatever] and the MDX won't run.

Soooo, sounds to me like it shouldn't be to hard to isolate ... either key or "fuel pump circuit".


OK you engineers may now proceed to show me the error in my logic [don't hurt me too much!!].
 

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The dash indicator (that looks like a key) will come on for two seconds when a key is inserted and the ignition switch is turned on. If the key is OK, the light will go out after the two seconds and stay out; when the ignition is turned off, the light will blink five times, once per second.

With a BAD key, when the ignition is turned on, the light will come on for two seconds and will then blink on and off (once per second) as long as the ignition is on.

So saith the service manual, p. 22-200 ('01).
 
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