No start issue
08-08-2019, 11:06 AM
#32
Addict
Rennlist Member
Rennlist Member
so as far as you can tell, you have spark and you have fuel. Like Tom said, something should happen. Help eliminate a fuel issue by putting a squirt of starting fluid in the intake. Any difference? A nice cheap test and maybe eliminate one possibility. My car is nearly back together and I'm starting to get real nervous about it starting back up.
08-16-2019, 08:03 PM
#34
Racer
Thread Starter
Still no go
Alright guys, here’s what I’ve done and am still looking for help...
Spark plugs are firing. Pulled plug wire on #2 cylinder, inserted new plug, grounded the plug, cranked and a spark jumps the gap. So we have spark.
Coil is firing from DME. Test light connected to green wire side and grounded, we have pulsing.
Rotor and Cap are secure.
Fuel injectors are firing. Pulled the fuel rail again, I held the rail while it was being cranked and all injectors are firing/pulsing.
Rebuilt DME attached with my stock chip, no change.
AFM connection cleaned, tested 5V signal coming to AFM from DME.
Have not tested AFM, but may pull it tomorrow and do the tests as described on Clark’s with a 9V battery.
Ref/Speed sensors - tested continuity and voltage coming into DME at the DME side of the wiring harness. Tested within spec according to ECU doctors video.
Timing - T-belt right on the mark at the crank with the crank at its own mark. Since this is an interference engine, I’m really careful here and just replaced belts/rollers/water pump with a front engine reseal.
Battery - fully charged and holding 12.65 volts.
Any ideas? Anyone know how to test the wiring harness from AFM to DME?
Spark plugs are firing. Pulled plug wire on #2 cylinder, inserted new plug, grounded the plug, cranked and a spark jumps the gap. So we have spark.
Coil is firing from DME. Test light connected to green wire side and grounded, we have pulsing.
Rotor and Cap are secure.
Fuel injectors are firing. Pulled the fuel rail again, I held the rail while it was being cranked and all injectors are firing/pulsing.
Rebuilt DME attached with my stock chip, no change.
AFM connection cleaned, tested 5V signal coming to AFM from DME.
Have not tested AFM, but may pull it tomorrow and do the tests as described on Clark’s with a 9V battery.
Ref/Speed sensors - tested continuity and voltage coming into DME at the DME side of the wiring harness. Tested within spec according to ECU doctors video.
Timing - T-belt right on the mark at the crank with the crank at its own mark. Since this is an interference engine, I’m really careful here and just replaced belts/rollers/water pump with a front engine reseal.
Battery - fully charged and holding 12.65 volts.
Any ideas? Anyone know how to test the wiring harness from AFM to DME?
08-16-2019, 08:47 PM
#35
Rennlist Member
What's the status of the fuel? Did you collect any of the fuel that came out of the rail. Can you (safely) get its fumes to burn at all?
Did you check for spark on the actual plugs in the motor? If you have fuel and spark in the same cylinder, it may not run, but the gas will normally at least pop or backfire or sputter of something. Only think I could guess if everything you say is true and the gas is ok, is that your flooding so badly it can't ignite, maybe. Someone suggested trying some starter fluid -- I'd second that. Maybe pull the injctor connectors off completely and see if you can get starter fluid to fire. If so, I'd be inclined to put the connectors back on, crank it for 1 or 2 seconds, then remove the connectors again and see if you get any ignition from the fuel that's in there. Temp sensor is another thing that can trick it full rich -- might be worth a quick check too.
The rotor can spin on the end of the cam and still seem very tight and secure. Did you confirm BOTH little set screw bolts are in their holes and secure?
Did you check for spark on the actual plugs in the motor? If you have fuel and spark in the same cylinder, it may not run, but the gas will normally at least pop or backfire or sputter of something. Only think I could guess if everything you say is true and the gas is ok, is that your flooding so badly it can't ignite, maybe. Someone suggested trying some starter fluid -- I'd second that. Maybe pull the injctor connectors off completely and see if you can get starter fluid to fire. If so, I'd be inclined to put the connectors back on, crank it for 1 or 2 seconds, then remove the connectors again and see if you get any ignition from the fuel that's in there. Temp sensor is another thing that can trick it full rich -- might be worth a quick check too.
The rotor can spin on the end of the cam and still seem very tight and secure. Did you confirm BOTH little set screw bolts are in their holes and secure?
08-16-2019, 08:55 PM
#36
Rennlist Member
You have spark and fuel, do you have air? When you did all that work did you put towels into intake holes and forget to remove? Check for air, you need air in, air out and compression.
08-16-2019, 10:53 PM
#39
Racer
Thread Starter
Hey Tom, no just check #2, figured if it fired its likely they all fire. I’ll check every spark plug lead tomorrow, all plugs are new Bosch copper. Fuel should be fine, at least it was 3 weeks ago. I don't let this car sit. Love it too much.
Yup, maybe I’ll pull the rail again tomorrow, pull the fuel pump fuse, squirt start up fluid in each cylinder and give it a try.
Id really like to test the AFM and sad to sad I’ll probably pull the speed and reference sensors and look at them physically.
Running out of ideas.
Yup, maybe I’ll pull the rail again tomorrow, pull the fuel pump fuse, squirt start up fluid in each cylinder and give it a try.
Id really like to test the AFM and sad to sad I’ll probably pull the speed and reference sensors and look at them physically.
Running out of ideas.
08-17-2019, 01:07 AM
#41
Three Wheelin'
OK, the fact that you are getting some sort of spark and fuel means that the speed and ref mark sensors are working, so you can likely rule those out.
Now you are getting into the no man's land of whether the spark is strong enough and/or occurring at the correct time, and if the fuel pressure/mixture is sufficient for cold engine startup.
Is the engine sputtering or in any way trying to start, or is it a pure crank and no start as shown in the short video from the first post?
As others have suggested make sure the distributor rotor hasn't come loose. Check physical ignition timing with a timing light to see if it is occurring at a reasonable point (say 5-10 degrees BDC on #1 while cranking).
Also check fuel pressure, could be very low and not enough to start a cold engine (though in that case I would at least expect it to cough or sputter).
Check the resistance of the DME water temp sensor (blue plastic connector) and compare to specs. Also make sure the AFM flapper isn't stuck.
Now you are getting into the no man's land of whether the spark is strong enough and/or occurring at the correct time, and if the fuel pressure/mixture is sufficient for cold engine startup.
Is the engine sputtering or in any way trying to start, or is it a pure crank and no start as shown in the short video from the first post?
As others have suggested make sure the distributor rotor hasn't come loose. Check physical ignition timing with a timing light to see if it is occurring at a reasonable point (say 5-10 degrees BDC on #1 while cranking).
Also check fuel pressure, could be very low and not enough to start a cold engine (though in that case I would at least expect it to cough or sputter).
Check the resistance of the DME water temp sensor (blue plastic connector) and compare to specs. Also make sure the AFM flapper isn't stuck.
08-17-2019, 11:59 AM
#43
Rennlist Member
You're getting good advice from people who have been there and done that, including from some who do it for a living. I'd leave the speed and ref sensors alone for now. The spark plugs and injectors would have no way to pulse if those sensors aren't working. If you pull them out, you add a variable going forward that you don't need yet. I'd say here are many more logical tests to try before looking for long-shots like that. Pull the connector off the AFM and try starting it. Try starting it with your foot to the floor. Check the DME temp sensor with a multimeter. Check the gas for signs of water. Check the fuel pressure. Post a video of your spark test if unsure whether is a strong clean spark. Try starter fluid with the connectors removed from the injectors. Run a compression test. Keep in mind the possibility of flooding and all it entails. Once flooded, a motor needs time to dry out before it will start. So don't just keep cranking and cranking after trying things. Also plugs can foul if flooded, so you might try different plugs as you go along. Keep at it, you'll find it eventually. 
08-18-2019, 07:32 PM
#44
Racer
Thread Starter
OMG. I am such a dolt.
I decided I was going down a complicated path (thanks GPA) so I went down the banana in the tailpipe path (thanks Humboldt). So I worked backwards on everything I touched when I was fixing that small leak at the gooseneck which is when it wouldn’t start.
I found that I did not reconnect the engine temp sensor (it was on but not snapped in) ... headslap.
So, after perusing all the “no start” threads on Rennlist, Pelican, etc. - we now know that it will create a “no start” if it’s not connected and sending information to the DME.
Many thanks to all of you...I’m now confident that I can chase a no start should it happen again.
I decided I was going down a complicated path (thanks GPA) so I went down the banana in the tailpipe path (thanks Humboldt). So I worked backwards on everything I touched when I was fixing that small leak at the gooseneck which is when it wouldn’t start.
I found that I did not reconnect the engine temp sensor (it was on but not snapped in) ... headslap.
So, after perusing all the “no start” threads on Rennlist, Pelican, etc. - we now know that it will create a “no start” if it’s not connected and sending information to the DME.
Many thanks to all of you...I’m now confident that I can chase a no start should it happen again.