'94 240SX dumping fuel - will almost start but not run

[honeybus]

My '94 240SX is sitting at my mechanic's service station.

He is honest but has only general competency on the 240SX

Problem: Car was running rougher and rougher over 3-5 miles so that I could not get home the extra 7 miles. I left it in a shopping center and had to have it towed to my mechanics.

Diagnosis: My mechanic says it is dumping fuel, and after a short look, he said it is constantly grounding and that is pushing out all the fuel (or words to that effect) he thinks it may be the ECU and would like to try a replacement that I have at home. (I don't think he knows where the ECU is on the '94 auto convertible! I will have to show him.

he did not manually read the codes (I can) because he cannot find the ECU (I can) and I don't think he has a code reader.

* * * * * * *Sceneraio:I took the 240SX convertible to a rec center with the top down. I shut everything off and then decided to put the top up, and close the windows. So I pou the ignition on for that, and then I left the 240SX with the KEY ON!! When i got back 2 hours later, the battery was dead.

After 15 minute wait, the 240SX started up fairly quickly. As I drove it the next 3-5 miles, the 240SX got rougher and rougher and I had to shift into neutral to keep the engine running. Then the shopping center and tow truck...

I mentioned the KEY LEFT ON thing to my mechanic, because on my '78 VW camper, this can cause some problems with the points (runing a current through them if they are closed).

Are there any other things to check other than the ECU?? that may be the cause. If this was my '78 VW camper, I would be suspecting a massive vacuum leak.

He could smell the fuel when we tried it at his service station. I ran a quick check of the resistance on the fuel injectors and they were all the same (I had just replaced #2 FI, and I could easily see that is was out of sync resistance with the other three. Not so this time,,)

Thanks

Barry Burneskis sends

[3Q Jay]

1. find a different mechanic.2. not to insult your capabilities, but my first thought was leaky injector. that's while i'm starting to read. then i get to the bottom and see you've recently replaced an injector.......you are wise to have it towed in rather than really mess it up.

fuel pump is supposed to shut off after a few seconds (key ON, engine OFF). but let's suppose that you've got a leaky lower o-ring on an injector: fuel pump keeps running flooding cylinder.

pull the plugs and let everything dry out real good. if you hydrolock, you can bend a connecting rod with a fresh starter and capable battery.hook in a fuel press gage and observe leakdown rates after turning key off.

fix the leak (i'm assuming). start with pinched o-ring on the replaced injector.

[aaronsnocker1]

I don't know if it will help but my 89 had a similar problem like it was spewing gas out the tailpipe and barely starting after cranking for a long *** time. It turned out I just had a cracked vacuum line going to the FPR. Thats just something easy to check.

[honeybus]

1. find a different mechanic.

2. not to insult your capabilities, but my first thought was leaky injector. that's while i'm starting to read. then i get to the bottom and see you've recently replaced an injector.......

fix the leak (i'm assuming). start with pinched o-ring on the replaced injector.

Thanks. I have been searching for a competent, non-ripoff mechanic for the 240SX for at least three years now.

Mechanic "A" just 3 months ago charged me $195 to tell me I had a bad #2 injector, and would charge another $200 or more to replace it!! I checked all four FIs and it was obvious that #2 was 'bad' per the resistance readings. I took the 240SX and a fuel injector to my Mechanic "Choi" and he R&R the FI in front of me, and said 'no charge', but I gave him a $40 tip anyways

Mechanic "B" had me spend ALL DAY at his shop and charged me $380. I had a check engine light with code 32 (EGR Code) and all he did was replace the temp sensor. I insisted on the old temp sensor back, and after he pulled it out of the trash, I measured it at home at room temp and it was in spec. The check engine light came back on the very next day. Mechanic "Choi" says to just run it like that; he won't even try to figure out the cause.

Mechanic "C" was a real drive away from me, about 80-100 miles. He came recommended as a competent mechanic but when i got to his shop on a Saturday, he had no books or info on a 240SX!! He called around to his peers to ask if they had anything!! We wound up replacing the rotor? and ignition cap because he saw a hairline crack (it was a casting fault, not a real crack) and I paid a hundred plus parts just to get out of there!!

My next mechanic, who I should have towed the 240SX to when the car died, will be Mid Atlantic Motor Sports in Baltimore MD

(2) A year back, my Mechanic "Choi" diagnosed a bad fuel injector (#1 FI) and he replaced it. At that time, I asked if I should have the other 3 FIs replaced, and he said no. So #1 and #2 FIs were replaced

I trust him to recognize a leak anywhere near the fuel rail.

I took two spare ECUs to my Mechanic "Choi" last night, and we will see....

One is my original ECU from my '94 (convetible - automatic) and one is from a clean '92 (non-convertible - automatic).

Will the '92 work in my '94??

Thanks In Advance

[honeybus]

OK, I 'm back from mechanic 'Choi's.

Replaced the ECU.

Pulled the plugs and they are very wet with gas.

Started the car after 15 seconds of cranking and huge white billow smoke out the rear, and a puddle of raw gas comes out of the tail pipe.

The on-site mechanic says the IAC unit, and the head mechanic says a ground is causing the excessive gas.

Not the vacuum line to the FPS. [Sorry - I should have said FPR - Fuel Pressure Regulator. JBB 11 July 2007 edited]

Any other suggesions?!??!


Modified by honeybus at 11:22 AM 7/11/2007

[3Q Jay]

we could guess too. i might even have better guesses from 3000 mi away that the blokes that have your engine in their face.

need data. sorry to have to be blunt, but the data will find the truth.start with fuel pressure and leak down (how long pressure holds up when key is shut off and fuel pump stops).

[honeybus]

Thanks, 3Q Jay, but I don't have hands-on access to the 240SX.

I can stand around and watch while the mechanic pokes around, but they don't want me doing any wrenching.

If these guys cant get t resolved by next week, I will take it to another mechanic, or would the collective wisdom be to just take it to a Nissan dealership and have them poke around??

What 'might' have burned out or grounded out if the ignition was left on until the battery died?? The first guess was the ECU, but that was incorrect

Barry

[xnyc]

did you replace the spark plugs after you swapped the ecu and are you sure the ecu is good? what happens alot of time is water runs down the side over the ecu and shorts out the injector prong. find a friend who has a good running car and put ecu in your car and change the plugs. i think the ecus you swapped in are also faulty.

[honeybus]

did you replace the spark plugs after you swapped the ecu and are you sure the ecu is good?

find a friend who has a good running car and put ecu in your car and change the plugs. i think the ecus you swapped in are also faulty.

Thanks, XNYC . . .

It's kind of hard to find another local 240SX comrade. 'Mike', from Wash DC gave me the name of a mechanic in my Fairfax Virginia area, and I got to see Mike at the mechanic's shop a few Saturdays ago.

Monday I stopped by a few Nissan dealerships' service deptments, and I was truly impressed by the service manager (Gold Team) at Passport Nissan in Alexandria Virginia. He claims to have the kind of mechanic I am looking for: servicing Nissans/Datsuns for the past 30 years, and familiar with the 240SX vehicles.

The Passport Nissan service manager was only at Nissan a few months, but he 'was' a VW aircooled buggy builder and racer with his brother for many years. The VW related people and shops he knows, I also know. He still talks VW terms (leak-down test), He listened to me in detail, and I feel comfortable spending $250 for a good diagnosis ($95/ hour). My previous mechanics are ready to rip me off !!

Last Saturday, mechanic 'Choi' diagnosed my '93 Honda problem as a bad distributor. I went out and got a new distributor and I knew that it was only three bolts and one wire harness plug to replace the distributor. He charged me $50 labor!!!

Three months ago, mechanic 'Merv' charged me $195 to diagose a faulty / failed fuel injector !!! Just the diagnosis was $195.

And mechanic 'Choi' just walks around saying 'ground problem' and won't work on the 240SX anymore...

Well, the tow to Passoprt Nissan is less than 4 miles, so I guess that's my next step tomorrow, Friday.

Thanks all. I will post the results of the Passport Nissan findings.

[honeybus]

we could guess too. i might even have better guesses from 3000 mi away that the blokes that have your engine in their face.

need data. sorry to have to be blunt, but the data will find the truth.start with fuel pressure and leak down (how long pressure holds up when key is shut off and fuel pump stops).

3Q Jay, and anyone else following this LONG series::

After 1 week and $195 diagnosis at Passport Nissan, they said I have a bad batery ($125) and a bad starter ($495) that would need to be taken care of before they could go any farther!!!

OK, I had it towed home the next morning ! ! !

Yes, the battery was bad, so I put in another that I had in the garage. The starter would not turn over at all, even with the hammer and the lead pipe convincers.. So I wen t to the junk yard yesterday and pulled an auto starter ($18). After readimg some on-line instructions on how to remove a starter, it was really a simple two bolts (14mm) and remove the battery wire from the central post on solenoid. No chance to install it yet. I have to get the 240SX inside my garage to work on it. Neighbors, you know

HOWEVER, (1) my gas tank is almost empty, and (2) there is a puddle of FUEL under the engine compatment (left side??) of the 240SX on my driveway. I picked the 240SX up on Saturday and notice the puddle of fuel late Sunday (yesterday).

This was with the battery replaced (Saturday) and the starter not working. On Saturday afternoon, I tried the ignition a few times, but got no action from the starter, so I went to the junk yard on Sunday for a starter. Saturday may be when the gas came out from underneath the 240SX.

There was NO fuel on the ground at Passport Nissan, perhaps because the battery was dead...

Ther WAS a BIG puddle of dried fuel on the ground at mechanic 'Choi's shop, when the 240SX was jumped with an Intestate battery outside the engine compartment.

3Q Jay, I am guessing that (1) there will be NO residual fuel pressure and (2) I will be able to see the fuel drain when I put it up on jacks in my garage.

Stupid mechanics (Sorry, I did not mean to malign the mechanics on this thread, but I really am frustrated. It HAS to be a simple fix, like a broken fuel line or vacuum line or something simple and visual and obvious...)

Thanks for listening.

[alexh]

Guys,

I hate to hijack this thread but the thread starters symptoms seem similar to mine and I have been trying to solve the problem myself for months now. I have posted before about intermittent hesistation. Recently it has become more common and sometimes lasts for several minutes. The symptoms are (91 240SX auto BTW)-

Always is able to idle although sometimes it goes into a mode were it drops to about 500 rpms.

Often has slight to very bad hesitation when accelerating. Sometimes it feels like no throttle. Recently it went into this mode for several minutes and I noticed black smoke (ie. unburnt fuel) coming out of the tailpipe and of course it ran horribly although strangely it was still able to idle.

Also, one time when starting the vehicle it ran extremely rough and again there was lots of black smoke for seveal minutes until it cleared out.

I went through all of the checks in the manual and many, many more.

From what I see here, I should check the following:

ECU- someone mentioned the water problem but I didn't believe it. I thought why would the water always affect just the injectors but apparantly it is possible. Can anyone tell me exactly what to look for?

Injectors - Seems strange that a faulty injector would get stuck in the on mode but I suppose it's possible. I assume there are some resistance specs in the manual which I should check?

FPR - check the hose on the FPR.

Thanks for any help.
Modified by alexh at 2:00 PM 7/10/2007