Ea81 starts but only runs for 10 seconds

[JRD]

I pulled an 87 EA81 out of an 82 wagon. Car had been sitting for 3 years or so due to an accident. Anyway, I took a look at it checked fluids and connected a battery, after a short amount of cranking it fired up. I ran it for a few minutes, and besides needing the valves adjusted I didn't notice anything else wrong with the run. So I thought i'd pull it out of the wrecked wagon and put it in my 81 wagon as a temp till I finished rebuilding the EA81 on the bench. Took a few hours to pull, install and swap the intake wire bundle. Get everything hooked up fire it up, and she fired right up, then died 10-15 seconds later. Took a look at the install, oh missed a couple vacuum lines, reconnected them fire it up again and the same thing. Tried a couple more times just to make sure I didn't miss anything else, no luck.:-\

 

I did a quick search but only found threads where the motor would run for several minutes then quit, and then refire and quit after several minutes. These were told to replace the rear fuel filter. I was thinking a fuel pump issue, but with the 87 motor the intake has less connections on the harness than the 81. The 81 has a couple extra sensors in the intake that the 87 doesn't have, I kind of think this may be part of my problem.

 

Any help would be greatly appreciated. Thanks,

 

John

[hatchsub]

Sensors in the intake will not keep it from running. I have a weber and threw out every single stupid sensor under the hood of my car. Do i get a check engine light? Yes lol. Do i care...nope. I know what its coming on for.

 

An engine needs three things to run..fuel, air, spark. If its running for a few seconds and dying we can rule out air and spark. I think you have a fuel problem. I would check the pump as well as the lower fuel filter as you said. That would be where i start. Dont worry about the sensors on a EA81 vehicle. They will not keep it from running.

[Crazyeights]

Don't the early EA81 cars only get power to the fuel pump if the alternator is working? It's been a while but you might check for power to the fuel pump. Good Luck!

[987687]

An engine needs three things to run..fuel, air, spark. .

 

And the 4th is correct timing. Did the disty get bumped and mess up the timing when you swapped it over? May as well check it. Plug wires on in the correct order?

[JRD]

Don't the early EA81 cars only get power to the fuel pump if the alternator is working? It's been a while but you might check for power to the fuel pump. Good Luck!

 

I was looking at the alternator last night and noticed the wiring has a ground connection that the newer alt does not have. But was thinking, why would it start if the fuel pump wasn't working? If I'm not getting fuel, shouldn't get light off (in theory). I'm also going to look at the fuel return line , as well as changing the rear filter.

[ettev]

I believe the EA81's fuel pump is feed from the fuel pump relay, which get's its signal from the distributor, not alternator.

 

Don't the early EA81 cars only get power to the fuel pump if the alternator is working? It's been a while but you might check for power to the fuel pump. Good Luck!

[hatchsub]

And the 4th is correct timing. Did the disty get bumped and mess up the timing when you swapped it over? May as well check it. Plug wires on in the correct order?

I didnt bother saying this because if it was the distributor it would run like absolute crap. He didnt say anything about it running poor. Just that it would run for 10-15 and then die.

[987687]

10-15 secs isn't really enough to determine if it's running very well or not though... it obviously isn't running well or it would run more than 15 secs.

[doobieryan]

But 15 seconds is long enough to figure out if it spits and sputters when you hit the gas which would tell you timing is off

[JRD]

Car doesn't miss a beat when it is running for those 10-15 seconds, but also doesn't have enough time to come out of high idle. The engine was running fine (except for the valve ticking) in the the other vehicle earlier in the afternoon, the day I did the transplant. I'm still on the hunt for the rear fuel filter, today hopefully.

[GeneralDisorder]

You didn't, by chance, forget to hookup the tach signal wire did you? It's the yellow one off the negative coil terminal. It also runs the fuel pump control unit - which runs at key-on and would fill the float bowl then cease to run after being started (with no tach signal) and the engine would die after the bowl empties.

 

GD

Edited August 24, 2010 by GeneralDisorder

[JRD]

You didn't, by chance, forget to hookup the tach signal wire did you? It's the yellow one off the negative coil terminal. It also runs the fuel pump control unit - which runs at key-on and would fill the float bowl then cease to run after being started (with no tach signal) and the engine would die after the bowl empties.

 

GD

 

I will look at that, but I'm pretty sure I did. What your describing sounds exactly like what's going on though. I've been waiting for your input, you always seem to have a good answer for trouble with these Soob's.

[JRD]

GD- Just thought of this after I posted the last reply. Would I need to swap the coil over as well? I thought I've read on here (somewhere) that certain motors need the correct coil or they won't run (or run well). I didn't swap the coil, just hooked up the 87 motor to the 81 coil.

[ettev]

I've been waiting for your input, you always seem to have a good answer for trouble with these Soob's.

 

Yep, he's the man, especially on these EA81's.

[JRD]

Ok, changed the filter by the tank. Still does the same thing. Is there a wire that I need to connect to some thing on that 87 carb? or a vac line that needs to be plugged? The carb has way more stuff than the 81 style carb. I have a tach signal, and connected the ground for the alt to a stud on the back of the alt. Any ideas?

[GeneralDisorder]

Hhhmmm - the coil should at least run the engine in the short-term. I wouldn't worry about that just yet but eventually you should get the correct coil for the distributor you are using.

 

On the carb there is an anti-diesling solenoid that cuts off the idle circuit fuel supply. Make sure you have power to that.

 

Other than that - plug in an inline spark tester and see if you are losing spark - if you are, verify that you are getting +12v to the coil when the spark dies and if you are then the distributor module is probably shot.

 

GD

[JRD]

Does it matter that the engine was running prior to pulling it out of the wrecked car? would the ignition module go bad that quick? The only thing I changed was the harness with the wires for the duty solenoids and sensors on it. I'll do the checks you talked about GD. I'll ask more questions that are on my mind if these checks don't pan out. Thanks.

[JRD]

Ok, I got it figured out. The alternator went kaput. So now it runs but the carb has issues. I'm going to put that in another thread if my search doesn't get me the results I'm looking for. Thanks for the assistance, guys.