Please help with no start concern

[DMCSPRINT]

Help with no start



Hello, was wondering if anyone has experienced this type concern or may have further suggestions on what to look for. To sum it up vehicle had been running fine drove it on about an hour trip each way , when coming back vehicle started to buck and battery light flickered on then ran okay then vehicle cut off at a light, I was able to get it to restart drove it about 5 miles cut off again as I was entered my development. I pushed it to my drive way and tried junping it with jump box, multiple times, used another vehcile with cables multiple times, finally vehcile started and i pulled it up into the garage and parked it. The next morning started it up fine , went to drive it , vehicle cut off again and could not get it to restart. I finally towed it to my work last week , and had a tech check it out, there seems to be no spark. I replaced the ignition resistor and still no start, no spark, put a new Bosch coil, same thing, even to be safe replaced the battery all still exact same results. The tech states the distributor is giving off impulse and working.
I have power at the plus side of the coil with key on
I have checked the impulse coil with a meter on omes and it does 0 out when checking
i have checked and there are 12 v going into the ECU when you checked the connectors
I have checked there appears to 1 v of power going out of the ECu with key in on postion(when checking the harnesses that plug into the ECU).
The tech states all the fuses/relays are good
Fuel pump is working
Battery light does come on when going to start vehicle
I have been told a possible impulse coil could be the problem but my tech states it working and other think maybe the ECU is bad. Appreciate any help yall can give as this is becoming pretty frustrating ( and expensive, ha) as I said the wierd thig is the vehicle drove fine until the bucking started and it cut out. I have bene lucky I guess and this is the first real/weird problem I have had with the vehicle since owning it. Thanks

[Jonathan]

Could you post a couple photos here of:

- the ballast resistor on the driver's side of the engine bay.
- the coil and bulkhead connections (with cover removed) in the passenger side corner of the engine bay.

Some other areas to check or confirm:

- wiring connections on top of idle speed motor, cold start valve, and warm up regulator (or any others not looking good and snug, like the vacuum advance solenoid)
- if you think you and your tech have everything checked out in the engine bay, you might start looking elsewhere like perhaps at the ignition switch. Not saying this would be likely, but if one or more of those connections up and under the steering column got loose, it could perhaps intermittently cut out the engine when everything else looks fine. Check on the inertia switch too while you're under there.

- did you get a bad tank of gas maybe?
- any goo coming out of your alternator? Could be it's on it's way to giving up the ghost and causing these problems.

[DMCMW Dave]

Help with no start

I have been told a possible impulse coil could be the problem but my tech states it working and other think maybe the ECU is bad. Appreciate any help yall can give as this is becoming pretty frustrating ( and expensive, ha) as I said the wierd thig is the vehicle drove fine until the bucking started and it cut out. I have bene lucky I guess and this is the first real/weird problem I have had with the vehicle since owning it. Thanks


I've seen dirt in the tank do this, it will plug up the input screen. Shut the car off a while and the dirt falls out and it will run again. Long shot in your case but worth looking at. This is the screen in the bottom of the tank.


How has he tested the impulse coil? It's an unusual failure but does happen. ECU failure is even more unusual. Also, and this is important, if the ECU or impulse coil has failed you will usually also see it as a fuel pump failure as the RPM relay, tach, and idle ECU are all driven by the ignition ECU. If it fails dead the tach will not move as you crank the car, and the fuel pump will either not startup at all or will "prime" and then drop out with continued cranking.

I'd be looking for a bad connection at the coil or ballast resistors to start.

[Kherns]

Maybe take a look at relay 102. Dirty connections on it can make you no start also.
First big metalic one with big brown and big white wire.

[Bitsyncmaster]

Usually the impulse coil will fail when hot but now you have problems cold so that may not be the problem. You would get about one volt out of the ignition ECU with the engine not running. That ECU drives the "-" side of the coil to ground.

Does your tach move when your cranking the engine and it does not start? If it moves (about 500 RPM) then your ECU is probably working.

How do you know it is not getting spark?

[Rich]

Agreeing with Dave and Dave in that it could be a fuel problem.

A pair of quick tests to check spark and fuel - you will need a helper for both of them:
1. Pull the coil wire off the distributor, hold the bare end 0.5in/12mm from a good ground, then look for a series of sparks across that gap when cranking.
2. With the coil wire back on and the air cleaner box off hold the air flapper valve/disk open a bit with a rod or other tool in one hand and spray some starting fluid into the intake while cranking. Start spraying just after cranking starts then crank for 5-10 sec while spraying. If it catches stop spraying. Wear safety glasses in case of backfire event.

Test 1 will verify indicate ignition OK (if spark will jump that gap) or not.
Test 2 will indicate fuel delivery problem upstream (if engine will run on starting fluid, then stop)

The tests start you on the right track. If you are sure your mechanic was correct about spark then try #2 first.

Try the factory Engine-Will-Not-Start chart if you like:

LINK: dmctalk.org....Factory-Troubleshooting-Charts-Engine-Will-Not-Start (http://dmctalk.org/showthread.php?3142-Factory-Troubleshooting-Charts-Engine-Will-Not-Start)

[DMCSPRINT]

Thanks I will post some pics next week. I am actually heading out of town for the week but will let my tech know all of your suggestions . I really appreciate the info.

[David T]

Agreeing with Dave and Dave in that it could be a fuel problem.

A pair of quick tests to check spark and fuel - you will need a helper for both of them:
1. Pull the coil wire off the distributor, hold the bare end 0.5in/12mm from a good ground, then look for a series of sparks across that gap when cranking.
2. With the coil wire back on and the air cleaner box off hold the air flapper valve/disk open a bit with a rod or other tool in one hand and spray some starting fluid into the intake while cranking. Start spraying just after cranking starts then crank for 5-10 sec while spraying. If it catches stop spraying. Wear safety glasses in case of backfire event.

Test 1 will verify indicate ignition OK (if spark will jump that gap) or not.
Test 2 will indicate fuel delivery problem upstream (if engine will run on starting fluid, then stop)

The tests start you on the right track. If you are sure your mechanic was correct about spark then try #2 first.

Try the factory Engine-Will-Not-Start chart if you like:

LINK: dmctalk.org....Factory-Troubleshooting-Charts-Engine-Will-Not-Start (http://dmctalk.org/showthread.php?3142-Factory-Troubleshooting-Charts-Engine-Will-Not-Start)

A quick and "dirty" way to confirm spark is to shoot a LITTLE BIT of Ether into the mixture unit and see if it runs even a little. A very quick and simple way to test for spark. If it runs at all that would confirm spark and send you down the fuel trouble tree. This sounds like a fuel problem except for the statement that you confirmed spark. I would be inspecting the fuel pump area too. It is a very neglected area UNTIL you have problems!

[Jacko]

A quick and "dirty" way to confirm spark is to shoot a LITTLE BIT of Ether into the mixture unit and see if it runs even a little. A very quick and simple way to test for spark. If it runs at all that would confirm spark and send you down the fuel trouble tree. This sounds like a fuel problem except for the statement that you confirmed spark. I would be inspecting the fuel pump area too. It is a very neglected area UNTIL you have problems!

My car has symptoms similar to DMCsprint's and runs fine until I accelerate. It spits and sputters and backfires. No one
above has mentioned a possible vacuum leak. I have convinced myself that is whats wrong with mine. I haven't had time to look at it but that's where I'm gonna start.