Car :   1986 EA82 TBI 3sp Auto.

 

Symptoms:    1.   Hard or No start when hot.  (have to wait 30-45 min to re-start)

                      2.   Stalls upon idle, or low rpm. once warmed up.    (have to wait 30-45 min to re-start)    

                      3.   Stumbling at highway speeds.  (no backfire)

 

 

Cure:    Well I'm thinking it's the fuel pump,  but the hard/no start when hot  issue makes me think possibly the Air or Coolant temp sensor.

 

Any thoughts????       

I would say it sounds like the symptoms of a bad fuel pump. check that your'e fuel pump is getting the tools it needs to do its job while the issue is happening. pwr and ground without any unwanted resistance with a voltmeter.. you can also check fuel pressure to confirm it is an issue.. not sure what the spec is for tbi. 

Coolant temp sensor could do those. I had one go bad, did all sorts of odd stuff. Except the stumble at highway speed.

situation has gotten much worse.

 

Car died 2 times on the commute home last night, Very violent stumbling , then engine dies.  Still starts up after sitting for 30-45 min.  While waiting to re-start during the cool-down, I turned the ignition on and felt the fuel pump, no buzzing or movement.   I ordered a new fuel pump, and have taken the car off the road until the part arrives. 

 

Usually a fuel pump works or does not.   Not used to one intermittantly not working, that's why I am suspecting other issues.  

 

I guess I will find out for sure when the new pump arrives this weekend.

The fuel pump on your car shouldnt run with the key on engine off, unless in diag mode. The symptoms you describe could be faults of the CTS MAF CAS fuel pump, fuel tank venting, and ignition sys (or as mentioned a grounding/wiring issue for any of these components)..... You get the idea. Ide open up the FSM and get out the ohm meter.

check the coils tower for any corrosion crusty powder in there - also sounds like an intermittent coil problem.

 

has anyone ever installed a fuel pressure gauge to their collection - as in a permanent fixture to compliment the other gauges ?

I reckon any efi car should have at least an idiot light type pressure switch so if not maintain say 30 psi - light on ,,,,,i

Update:  

 

new fuel pump  = did not fix problem.

 

coil swap  =  did not fix problem.

 

 

Symptoms have gotten worse. Now it will only stay running for a few minutes , then stumbles and dies.  will not re-start (until sits for a few hours)

 

Thinking of swapping the AIC valve next, or put a new fuel filter on it. 

Car died 2 times on the commute home last night, Very violent stumbling , then engine dies. 

 

This type of behavior is a good indication of a fuel problem.  Electrical problems are usually sudden death without the hurt dance.  Mechanical problems are accompanied by lots of noise, smoke or vibration.

 

Usually a fuel pump works or does not.

 

Not necessarily.  My experience was a slow progressive development of no start problems accompanied by the engine sputtering out while driving down the road.

 

That being said, if you have replaced the fuel pump then it can be eliminated as a cause.  I would look downline in the fuel system to see if there was another cause for a fuel interruption.

F'd up ecm maybe? On a ea81t i had, the ecm would not run the pump sometimes and other times it would. I replaced the fuel pump since it only worked the first time i started the car after it sat 7 years. When it did run it ran rough and almost acted like it was missing with that ecm. The car came with a spare one so i put it on and she purred like a kitten and ran like new with 136k.

Get a fuel pressure gauge. Make up a tee and put it in the line. See what it does during normal and failure modes...

Well had a little time to tinker on it this weekend. The symptoms have gotten much worse as the car is now sitting.

 

Currently The car will crank, but no start at all.

 

popped the dizzy cap, found the screw holding the rotor laying on the cover plate (????)  Re-connected screw, cleaned up all contacts.

 

Made no difference, car still no start.

 

I have noticed the fuel pump is only buzzing when the ignition key is turned past the on position (when the starter is engaged) not buzzing when ignition in ON position.

 

 

On a side note:  Before any of these problems started the alternator was over charging (high volts) , this was going on for months before the current problems.

 

                           The day before the symptoms started, I got stuck in a snow drift and had to really rev the crap out of the motor to get unstuck.

 

Hopefully I will get some more free time to solve this mystery.

Fuel pump runs in start position. For a short burst when switch set from off to run. Or when the engine is running

Clean the spark plugs.

Quite likely they are fuel fouled from the faulty rotor,

Break out an ohmmeter and test youre pickup coil in the disty., check wiring for hot spots or melting in ignition system. i agree with checking fuel pressure. check for spark, and how strong it is if you have it. and check plugs as well. you need three things to run. fuel, spark and compression. so once you know you have all three, you can diagnose from there. don't overlook the easy stuff. we all tend to do it.

Had these symptoms with ej 22. Would pinch fuel line when hot so no fuel pressure. Ended up replacing the fuel reglator and one injector. Seemed to be flooding. Helped, but what it ended up being was both temp sensors. 

 

i agree with the earlier reply. They fake the engine and can flood. Try the pinching inbound fuel line while someone starts. If it starts you are flooding. Fuel pressure reg or temp sensors. ECU last resort and only if you have a swap.

Fuel pump pressurizes at ignition on and stops. Turns back on when ignition is running signal. A test is take the return fuel (if ea82 have those) and remove at firewall. Put the hose in a liter bottle and start car. Run very temporarily as fuel will quickly fill the bottle. It is amazing how much unused fuel goes to the injectors that is not used and returns to tank. 

 

it really sounds like temp sensors...

So I checked the codes.

 

It is flashing 1 long , 1 short   =   11   crank angle sensor circit (dizzy problem)

 

its also flashing   1 long  , 7 short   =    17  ???????   (WTF)  ??????

 

I have a bunch of old dizzys to try swapping out.  

17 is for the starter switch.

Either the ECU never sees 12V from the starter solenoid or it sees 12V all the time.

I am not sure why 86s have 3 different codes for the starter switch.

 

Not sure about 86s,but,my 84 will show code 11 anytime the engine is stopped.

Based on the the description of over charging and revving, you may have taken out the ecu for any circuits that are involved. I think it is the crank angle sensor signal that tells the fuel pump relay to turn back on. 

 

ecu will also check temp and control injector. 

 

Usually ecu is pretty cheap at salvage yard. Hard part about troubleshooting OBD 1 subes is the funcky led's. This is where a good manual that talks about input signals on early ecu cars is helpful. I eventually went to a obd2 with codes. You can do an ohm check on the temp sensors or they might be open.

I guess my next plan of action will be to replace the alternator and the ECU.   I have another ECU from a 1988 ea82 3spd auto. that i know is good.  

I think its normal to see a code 11 when the car isnt started, key in on pos., because it wont see a pulse from the ignition to fire the injector unless the engine is running. if youre getting it while running then i think you should be concerned. on mine i get code 11(ignition pulse) and 12*(starter switch open i think) when not running every time. but mines an 84 w/mpfi.

Well I found another spare hour to tinker on the car.

 

Replaced the Alternator and the ECU.  

 

Still no start.

 

Going to try swapping the dizzy next.  I also have some new spark plugs stashed somewhere 

 

Here is my list of parts that I have replaced so far.

 

Coil

Fuel Pump

Alternator

ECU

If you havent replaced the fuel filter yet i would try that any time i have any running issues thats the first thing i do there cheap and easy

Did you ever resolve the issue? temp sensors ? 

It is on the back burner, been running my brat and coupe.    I have thrown a new set of plugs at it the other weekend.  Still wont start.  Hopefuly I can get a spare hour or so to tinker with it.

I found a spare dizzy that I will try next.