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greggbrat

EA82T starts and then stops immediately

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Its a 1987 RX with an EA82 Turbo motor.

 

I just finished putting in new intake manifold gaskets.....hence I removed intake manifold and then reinstalled. More than likely I caused the problem during my intake manifold removal and installation.

 

Now the cars starts (after about 10 seconds of cranking the starter) but then shuts down within 5 seconds.......as if it has run out of fuel. It runs great in that 5 second duration. If I let it idle it will run longer than if I rev the engine.........which seems to indicate the fuel delivery is just not happening.

 

I know that the fuel pump is working when I turn the key.....I disconnected the fuel line from the fuel filter and watched it spurt out a good healthy stream of gas for the 2 second duration that the fuel pump primes the gas lines. I ran out of daylight to perform any other checks.

 

Here are some of my thoughts.....

 

Did I put the vaccum lines on incorrectly? I was reading that the fuel pressure regulator has a vaccum line attached. Would the wrong line cause it to shut down?

 

Are there some wires that I may not have reconnected? Or wires that came loose?

 

Thanks,

Gregg

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check the hose that comes from the bottom of the intake plenum(between the MAF and throttle body),its easy to knock off and not notice

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mass airflow sensor,it comes off the air filter box and has a wire harness attached to it(measures intake air volume and signals fuel delivery rate accordingly)

 

look at the aluminum pipe that says "turbo 4x4".On the under side in the middle you will see a 5/8 hose.Make sure both ends of it are attached to their respective fittings

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I do know that the 5/8" hose is connected to the aluminum duct and the other end goes pretty much straight down and slightly back towards the rear of the vehicle to a connection.

 

I dont recall disconnecting anything from the air box.......with the exception of the large hose (3 or 4 inch diameter) going to the turbo.

 

I actually installed the new intake manifold gaskets without disconnecting any of the fuel lines.......so I know all the fuel lines are still correctly attached. And I only disconnected 2 electrical connections. They were both sensors (looks like a spark plug with a single wire attached). One was on the top of the motor behind the intake manifold and the other was under the motor next the oil filter.

 

What about the fuel pressure regulator? Could I have mucked up a connection on that?

 

If I did muck up the connection to the MAS would that explain the motor only running for a few seconds (and having to crank the starter for 10 seconds to get it started)?

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I recently had the same problem,and it was that hose I mentioned,but for the love of god,that sensor behind the in manifold,thats your knock sensor,and they get very fragile and expensive!I dont know if a failure of that sensor would screw up your startability that much,but try to stay away from that from now on($325 can,approx$200 us)

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there is also a little hose that connect to the air intake tube. (the 3" round black one.)

 

it sits facing the front of the car into the fuel rails.. check this one..

 

also check the one that comes off the passenger side valve cover and goes to that 3" round black tube..

 

any one of these off, would cause it to loose vacuum and suck air..

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Meeky Mouse,

 

I will check those hoses but the problem seems much more dramatic than just a vaccum leak. I think if it was a vaccum leak it would run rough, cough, sputter, etc. My car starts after about 10 seconds of cranking the starter and then runs fine at idle for about 5 seconds (less if I rev the engine).

 

Logic seems to indicate that its not getting any fuel except for the 2 second burst of gas the fuel pump provides when the key is first turned on. I also noticed that if I do not turn off the key it wont start again......which implies that the only fuel is provided by the 2 second burst provided by the fuel pump when I turn the key on.

 

I am going to do some investigative work today. I am thinking of hardwiring the fuel pump (just as a test) and see if it will run.

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I have read that some vehicles use the signal from the oil pressure sending unit to activate the fuel pump. Does the EA82T use this design?

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my turbo just did the same thing, and it was because I forgot to plug in the electrical connector to the MAF.......

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I don't know if the turbos work the same way, but I can tell you on a non-turbo '91 Loyale, if the hose to the Idle Air Control isn't on (or not on right), it will do pretty much what you describe.

Mine will start, run normally for a few seconds and then drop dead.

Hope this helps.

Good Luck!

-Louis-

'91 Loyale 4wd 5spd Wagon

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Originally posted by greggbrat

I have read that some vehicles use the signal from the oil pressure sending unit to activate the fuel pump. Does the EA82T use this design?

 

Not that I am aware of.. blieve its signal come from the disty via the ECU... if the disty stops spinning, (or if something senses its not spinning) the fuel pump stops working.

 

 

i'm with mick on the train of thought that something like th MAF isn't plugged in .

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I never did unplug the MAF to begin with. I checked it this morning. The MAF is plugged in......all the hoses are connected.......none of the electrical connections are loose.

 

The fuel pump is working in a steady stream. I unplugged a fuel line and ran the gas into a jug to check. The fuel pressure regulator is hooked up via vaccum line.

 

UGGHHH!!!

 

I definitely know that fuel is getting to the injectors......and the injectors are at least giving enough fuel to let it run for a few seconds.

 

I also wanted to make sure that I didnt have another coolant leak from the intake manifold pouring into the cylinders so I drained the coolant.........no change......it still only runs for a few seconds.

 

Any other ideas?

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i smell a vacuum leak too. make sure your oil cap is on tight. check your ECU codes too. maybe a jammed open choke or something?

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greggbrat, just wondering if you found the solution to this problem as i am having the exact same issue... im still searching for my gremlin...

 

RllyWgn

87 GL Turbo Wagon *intercooled*

5 lug conversion

exedy clutch

No mud... damn desert

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I replaced the entire intake manifold (from a junkyard) since I thought perhaps I cracked the intake.............after I put everything back together I had the exact same problem. The motor starts.......runs for a few seconds and then dies. Does anyone have any ideas??????

 

Thanks,

Gregg

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Maybe a bad fuel pump relay or worse a bad ECU :(

 

the fuel pump is controlled by the ECU, when you crank the engine over the ECU will run the fuel pump for a specified amount of time then it expects to receive a ignition pulse single, if it doesn’t receive the signal it stops the pump.

 

Try back probing the relay and see if power is shutoff to the pump before or after the engine dies.

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The fuel pump is working correctly. It cycles on for about 2 seconds when I turn on the key and then runs continually while the engine is cranking. I pulled off a fuel line and pumped gas into a jug to check the operation.

 

Any other ideas? The vehicle ran fine before I replaced the intake manifold gaskets.........so I am assuming I broke it somehow.

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unless you have a internal leak or stuck closed fuel pressure regulator it will run with or without the vac. hose connected. it makes the presure rise a bit.

 

the MAF sensor is what tells the car how much air is coming in. If air is getting in somewhere else it will be confused and not regulate the mixture correctly.

 

important things I would look at.

the temp sensor on the manifold. (2 wire)

the TPS on the throttle body.

make sure the fuel pump is running like sugested. you can check this at the serial monitor connector(13 pin connector) blue with brown wire.

make sure all connectors by the battery are hooked up ok to eng. harness.

 

good luck

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I checked a few more things

 

The engine runs fine if I spray fuel right into the throttle body. While it was running (with me spraying fuel into the throttle body) I watched the fuel pour into a container from the fuel filter. This tells me my fuel pump is working just fine.

 

So the following works.

 

Fuel pump

all electrical ignition components

 

Apparently my engine is fuel starved. What would inhibit the fuel from getting into the cylinders given that the fuel does get through the fuel filter?

 

What I dont know is if the fuel injectors are actually firing. How can I tell/check?

 

And how can I tell if the fuel regulator is working as it should? I dont think its the fuel regulator because I just replaced the entire intake manifold assembly. The only thing I reused from the old intake manifold assembly was the wiring harness.

 

 

Any more ideas?

 

Thanks,

Gregg

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are the fuel lines hooked to the right connections?

 

the hose from the fuel filter should go into the middle fuel rail..

 

the return hose should go into the fuel rail that runs from the pressure regulator..

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Update

 

I checked the fuel lines and they are all hooked up correctly. As stated earlier in the post I didnt even disconnect the fuel lines when this problem started happening.

 

I just pulled a fuel injector and watched it spray gasoline.......apparently the injectors are getting power.

 

This is the most confusing problem.............

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hmm did you unplug the spark plug wires from the distributor cap? if so sheck the fireing order again.. it goes counterclockwise, not clockwise.. (had this issue, but my RX started and ran on 2 cylinders)

 

double check and make sure the knock sensor is plugged in as well.. i know if the wire/plug gets bumped they like to break off..

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I didnt disconnect the plug wires from the distributor........and I labeled them all at the spark plug side.

 

Would a bad knock sensor (or disconnected knock sensor) cause this problem?

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