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EA81T miss, stumble and no start.


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Hi all just as the title says i have a 1984 ea81 turbo coupe 3at 84k miles been sitting for 6 years. it originally had bad gas, drained put in premium withh new filter. car would start and die immediatley. new cap and rotor and now car runs but has a small miss at idle. plugs are okay, if i step into the gas it sputters and stumbles and i have to either let off or push in harder until it accelerates. today it was pretty warm, the car would not start back up it would just crank and crank. then i kicked the fuel pump bracket and rattled the pump and it started and died. hit it again and now it runs again. Im thinking the fuel pump is causing this. only code i have had is a code 22. Pressure or vacuum switch. but it hasnt came back. any input would be great. also not sure what fuel pump to get. replacements seem to be either 3-4 psi or 70-90. i think i need i need a 40-50psi pump? thanks for any help.

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Thanks for the help everyone. I got a new one ordered today. Decided to go with the airtex. Plugged in the test connectors and after a while I got a code 32 oxygen sensor or circuit. And 34 which is the vaf I believe. Didnt get these codes before. And they went away. I guess I'll get the diagnostic trees from all data and test to confirm they have an issue. Any more input would be great. Thanks all. Love usmb.

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With the new fuel pump the car will start but runs badly and dies. eventally will not start at all until you clean the fouled plugs and open up the throttle all the way while cranking. then dies once plugs are fouled again. its running way rich. obviously way to much fuel. I hooked up the pump just like the old one was. so nothing is different besides the pump. any ideas? it ran before would have no starts at times but it didn't run rich like this, it seemed to be running  lean before because it would ping and cut out if I tried to accelerate. I tested the coil and I had 1.1 ohms primary and like 10.12 k ohms secondary I think that's right. anyway any help would be great. its getting frustrating.

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Going to install an adjustable fpr after the fuel filter with a pressure gauge. I think ny regulator failed and is letting to much fuel pressure to the injectors. Obvoisley there is no replacement other than aftermarket. I will try this and see if I can get it to run. I post what the verdict is. Any more input would help a lot.

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If it has been sitting for six years I would very carefully go over all the EFI electrical connectors and make sure they are clean and tight because a bad connection will cause problems and it seems you have a car throwing up different codes but not necessarily any real problems, Have you had the injectors serviced and flow tested fuels go off and gum up things like your Fuel pump but as well there are small basket style filters in the top of each injector they can become blocked stopping the correct amount of fuel being injected ,

That will cause a miss or stumble much like you are experiencing, But as with Carburetors remember most "Fuel System" problems are in fact Ignition related make sure all of the Ignition system is up to scratch, Dissy cap Rotor leads plugs connections earth points for both the Engine and Coil and Module in the Distribution as corrosion can and will cause bad earths and problems as well there,

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The regulator passed the vacuum test but that does not mean it couldnt be stick open/closed I still ordered the adjustable fpr with gauge to hook it up anyway so I always know what I am running. Also replacing old fuel lines as I have the metal fpr/fuel line unit off. Which is a massive pain to remove on this ea81t. Ive been inspecting grounds wiring etc. Thanks for the input all I will check out all the things you have suggested.I will fix this stubborn little subie. Just waiting for the rain to subside. Will update soon.

Edited by SoobDood05
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So I replaced all the old fuel hoses and cleaned out the metal fuel lines. made sure all wiring was correct got everything put back together with a fuel pressure gauge on it. it started right up this time. the fuel pressure is at 28- 30psi at idle. and raises with rpm. so I would say at this point the regulator or return line are not the culprit. it is running a little better. im getting a good burn on the plugs but there is still a miss at idle. and it still stumbles when I am driving after a bit of driving. I tested the tps, it does not have a clean sweep of voltage. from the green/red wire backprobed and black lead on batt neg, it starts out at 4.9v and once it goes to almost half open open the voltage drops right to 0.3v. I cant get to any specs for the tps at the moment. but this is where I am at as of now.

Edited by SoobDood05
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I spoke too soon lol right after I posted it would not start again. just my luck! I had just installed brand new ngk platinums. the coil tests out okay but there is a little bit of oil leakingout where the plug boot fits in. I cleaned it with alcohol and it started but runs like garbage and cuts out bad. still chasing gremlins lol

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Used an inline spark tester and I'm getting spark. And the spark plugs have fuel on them so I have fuel. Anyone have specs for the ea81t cts this thing is very strange. Getting like 10 ohms at 50-60 degrees. That seems wrong to me. I took it off and it isnt even submerged in coolant it just uses an air passage? The movable peice doesnt change the resistance values either.

Edited by SoobDood05
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So it looks like the component I was checking was the auxiliary air control valve. something of an electronic thermo switch to control idle. I found the cts from alldata and its reading about 4.5k ohms at around 41 degrees f. wich is about right. spec is 2-3k ohms @ 68 deg f, and 7-11.5k ohms @ 14 deg F. The battery is starting to die down from so much cranking so I need a charger. im pretty sure the timing is right. the rotor is Pointing just before number one with the TDC mark lined on the crank pulley. the rotor is lined up with the arrow on the back stamped into the distributor wich I feel is correct.I have even rotated it 180 out just to be sure but no dice .Not sure if I am getting fuel/spark at the wrong times, or spark is getting blown out. im wondering if I have a bad ecu but I cannot find another and am low on funds.  someone has been all over in the wiring in this car. I have been searching it all to make sure is all okay. any extra help would be great.

Edited by SoobDood05
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thinking back to Tweety and his EA82 spfi conversion to an EA81. Had all sorts of problems and some may have been related to a not so healthy engine it would seem on tear down. The rebuild did not see any fuelie stuff other than an inlet manifold so the spfi did not a get a chance to prove itself.

 

I hauled a near 9 year sitter home, tried to start it on that old fuel. Did all sorts of things and eventually got it going real nice on fresh fuel. What then got me was letting it sit another six months. Next start was difficult and ran like crap. Tear down was needed and found shiny wet like black sticky gum stuff that whiffed of stale fuel :( on inlet valve stem and a bent push rod to explain the no compression on that pot #3. I also accidentally found same on same position inlet valve #4 on the other head. I suspect the fresh fuel dissolved the barnacles on the inside of the tank and released them into the fresh fuel and gummed up my valves.

 

So, moral of story may be, efi needs better more even compression radings to perform nicely - how is your compression ?

Edited by jono
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All the plugs fouling evenly?

Compression test is always a good idea.

 

I would:

 

Make sure the spark is strong enough to jump a lenghty gap

Pull or back probe(You can use the check connrector plugs under the dash instead) the ECU plug and recheck the CTS resistance there,

Ditto for the airflow signal-flap open,flap closed

Ensure the 1psi boost switch on the rh strut tower is not shorted,

Make sure the injectors hold presurre after shutdown.

Check for unmetered air leaks in the intake tract even though the motor seems rich.

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Okay. just got the compression test done. I have 120-122psi across the board. and they all hold very well. I used a different type of spark tester( Gap jump type) and it seems there is no spark there now. wich there was before so this is weird. if I put the spark tester inline with the coil I can hear it zapping but it wont jump the .040" gap. I don't think I have a good enough connection. but atleast I know spark is coming from the coil. but anything after the disty I cant get anything. wich I did have spark last week when I chacked And yes when the plugs do foul they all foul evenly. now I just have fuel soaked plugs. so I guess its time to find out where my spark went. I will check the other stuff you guys suggested as well. I was curious if the injectors were varnished. but I haven't pulled them yet to see. its cold and raining so once I get the chance I will further diagnose the ignition system.

Edited by SoobDood05
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Pickup coil test out good. 158 ohms. spec is 130-190. air gap is .010" wich spec is .08-.016" wich is the nippondenso disty. looks like its ben replaced before. has part number written on the back of it. and the plastic cover over the ign module and pickup are chipped from someone trying to pry them off.

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Ummm...

EA-81Ts should have a Hitachi 4 wire Hall effect ignition module.No pickup coil.

It sounds like the distributor was replaced w/one from a carbed car.

 

I think the turbo coil is a little lower resistance than the carbed one.

Maybe the ND disty could not handle the turbo coil.

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Really? Thats interesting. I have the nippondenso disty. Has pick up coil 2 wires go to ignition module, then two wires out to harness. Harness has two extra female connectors that have no wires going to them. Could someone maybe give me an picture of there ea81t distributor and wiring?

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Dude thankyou that helped me tons. i am saving that manual for sure. it looks like this car definatley has the incorrect distributor. explains why it would always ping and never go fast because there was no knock control. looks like i need to look into getting a new one. rockauto has a few. i wondered why the parts store gave me the wrong cap and rotor for this thing.

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