New Member...need help please....;

DgLK4

Registered
Hello To all !

I heard thru a mechanic at a car show about this site, I have read thru alot of the threads and find it very interesting and see all the love for the MRK VIII.

Anyways I have a small somewhat small problem with the Mrk that I bought for my daughter about 2 weeks ago.

It's a 1993 blk/blk with 160,359 miles on it. Although the high mileage the car ran great and belongs in a showroom...one owner.

Daughter drove to school like any other normal day. Came out 4 hours later only to find that it will not start. Cranks over strong..

Had the car towed back to the house and has been sitting for 3 days now.
At first i thought that maybe she had a frozen gas line so i put in a bottle of gas antifreeze. the car has a little over half a tank of gas in it.
the temp here in MA is in the teens. but it was also in the teens the week before and didn't have a problem.

A neighbor mentioned the fuel pump. But there was no indication of it going bad, as far as the typical hum that i assume you would here before it goes.

I not a mechanic by all means. But i pressed the valve on the fuel rail to see if gas would squirt out because, I figured that if the car is fuel injected, there would be pressure in the rail. well it didn't gas only dribbled out.

What else would there be that I can check before having it towed to a mechanic, I need my truck back for work, that's she's driving to go back and forth to school.

sorry for the long post, just trying to get a get description of the problem..

Thanks in advance to member that could find me a solution and the keys back to my truck ..

Tom/MA
 
Welcome! :)

Fuel, spark and air. That's what is needed to start and run.

Fuel.

The fuel pump is first to test. You do test it at the schrader valve on the fuel rail. It is best to use a fuel pressure gauge. 39 psi is normal. When you turn on the ignition, the pump should run for a second or so and build pressure enough to be ready to crank. You can make sure you have adequate pressure by cycling the key on and off a few times forcing the fuel pump to cycle and build pressure. Usually once the fuel pump dies, it is forever. If the problem is intermittent, most likely the fuel pump is not the problem even though it may be weak.

The cam sensor is responsible for fuel timing. It is a common malfunction in these cars for either the cam sensor or connecting harness to go bad with age. This problem usually begins intermittently and worsens with time. Sometimes it will start and sometimes it won't. The cam sensor is located behind the power steering reservoir. Do a 'wiggle' test and see if the connection is good. The sensor may need replaced and/or a new harness connector may need to be spliced in. An odd fact with the cam sensor is the car cannot start without it but often can run without it once started.

Spark.

Typical maintenance items are the spark plugs and wires. You can pull the plugs and check the gap, replacing if necessary. The spark plug wires are also suspect if age is a factor. The coil packs while generally reliable may also be suspect.

The more common cause in a disabling spark condition is the crank sensor. The crank sensor is responsible for spark timing. Many times the connector plug is corroded and simply unplugging the connector and hooking it back up will get you back up and running. This can also be a frustrating intermittent condition. The crank sensor is located on the front bottom passenger side of the block, slightly behind the AC compressor. Again, a 'wiggle' test on the connector may prove helpful and the sensor may need replaced and/or a new harness connector may need to be spliced in.

Air.

A metered amount of air is required to start and idle. Since normally, the accelerator is not depressed during the start cycle, the IAC(Idle Air Control) valve is responsible for the correct amount of air through the throttle body. If you are comvinced you are getting fuel and spark, the engine may actually be flooding during extended cranking if the malfunction is IAC related. If so, depressing the accelerator to the floor and cranking will often relieve the situation and allow the car to start with some coaxing of the throttle. Be aware the IACV on the early Mark VIIIs(gen 1) is a PITA to replace due to its' location.

Hope this helps. :wink2-green
 
Great post. Good topic for our newsletter.
When you first turn the key, you should hear the fuel pump cycle/hum in the rear for a second or two.
 
Thanks for the info Driller, and Scottie....just got in and I found the sensor behind the steering res., but had a really hard time finding the crank sensor....
Anyways my daughter had one of her girlfriends boyfriend come by the house and could not hear the fuel pump at all humming.

Now i thought that if a fuel pump hummed then that would mean that's it on it's way out. but I guess i was wrong and it's the other way around.

He told me that with the mileage on the car that there was a very good chance that it is the original pump..

So now the hunt is on for a fuel pump...any suggestions for a good cheap pump....and also is the pump in the tank or is it located outside of the tank so that maybe it's something I could do myself ??

Thanks in advance !

Tom/MA
 
Check for fuel pressure first with a gauge!

The fuel pump is inside the tank. Do not buy a factory fuel pump unless you have extra money to burn.

Look for a Walbro 190 or 255. One of our sponsoring vendors, SuperCoupe Performance, can set you up with what you need.
 
Now i thought that if a fuel pump hummed then that would mean that's it on it's way out. but I guess i was wrong and it's the other way around.

Tom/MA

Increased humming indicates the pump is getting worn out...zero humming means the pump is jammed. Time for new one. But do what driller said first...check your pressure. It's cheap and easy.
 
If the fuel pump is just starting to go, you can usually "fix" it temporarily by banging on the fuel tank with a hammer.
 
If the fuel pump is just starting to go, you can usually "fix" it temporarily by banging on the fuel tank with a hammer.

I would second that...as strange as it sounds (contrary to his avatar, Dave is not a wacko) , it does work as a short term fix.
 
Does this mean I should replace my 167,000 odom with a walbro before it goes posterior up?I am doing rennovation work.
 
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Does this mean I should replace my 167,000 odom with a walbro before it goes posterior up?I am doing rennovation work.

at 150,000 miles my original pump died at the dragstrip.

when 300,000 miles rolled around I replaced the OEM pump that I put in at 150,000 miles with a 255 walboro pump.

I didn't want to give an OEM pump a second chance to leave me stranded, so I changed the 150,000 mile pump in a pre-emptive strike against getting stranded again.

At 160,000 I would say you are on borrowed time my friend.

First time doing it, it will probably take 3-4 hours...without a lift
after doing 4 or so, I've narrowed it down to about 2 hours, not rushing. taking my time.
 
Driller, thanks for the link, one of my daughters friends brought this to my attention.. Do you or anyone here think this is the same and would work on her car ? http://cgi.ebay.com/ebaymotors/NEW-...010QQitemZ200048732131QQrdZ1QQsspagenameZWD1V

Thanks for all the quick response's

I mention the other night over dinner to my daughter about your web site and all you guys with the ideas of what it could be, her comment was are they good looking ?.....typical 19 year old !
 
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