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milesengineer2

New Member
Joined
Aug 24, 2002
Messages
122
Got my new motor back together and finally tuned out right. Take it for the maiden voyage and it runs great!!! Get it back into the driveway and put it in park and let it idle back down. All of the sudden it just dies. Tried to restart it as I was previously having a problem with it doing this and that turned out to be a bad maf. It just cranks and cranks. Pulled the wire off and checked spark, none. Figured the crank sensor went so I put a new one on, still nothing.
So I start the diagnosis per gnttype and check the orange wire from the battery to the computer, 12.8 volts, the pink and black wire to the ign module, 11.8 volts and all the fuses. Everything was fine.
Then I replaced the ign module with an AutoZone one, same results. Dont flame me just trying alternatives.
Next I checked the injectors to make sure they are getting power. Nothing. Key on no power, cranking it no power.
This has narrowed it down to a few things, crank sensor, ign module, ECM or cam sensor (maybe). My question is, Is there anything that I missed checking. What about the ESC, does it have anything to do with the no spark and no injector pulse? Would any of the fusible links cause this, I thought they killed all power when they burnt.

Sorry it is so lengthy, but wanted to make sure I covered all the steps I have taken to check this problem.

Thanks
 
Saved this
This was posted by Jimmy Da Testa the other day...rather than try to tell you how to look...I am going to let you read Jim's write up as it is more logical than most of the stuff I write and cuts to the chase. Read point # 3. (the second # 3) LOL By the way, most parts places have a noid light for about 7 bucks...




<<<<<<Hmm...are you the guy that IM'd me about a noid light blinking but no start?

OK, to diagnose ANY car, you need to find what you have and dont have. The way *I* usually go about it (which might not be right to some people, but its methodical and consistant so I stick to it.

1) Note the check engine light (if EFI). If its not on, STOP and find out why. Listen to how it cranks. I can pick out compression problems doing this. If you are in tune to your car, you can too. Listen to the starter as each cyl comes up on compression stoke. You'll hear the starter slow down a little at that point. You bight hear deerdeerdeerdeer, where a dead cyl m ight sound like deerdeeeeedeerdeer (great sound effects huh?)

2)Depending how accessible the intake is, I'll shoot 3 or 4 seconds of carb cleaner into the plenum. Either thru the throttle body, or the brake booster vacuum port. If its a lack of fuel problem, the car may start, it may simply kick. If it does either, its time to look to fuel system (usually, although enrighening can bring out a low sec output problem too, so dont take my suggestion of fuel as law)

3) If the car kicked, I'll put a FP gauge on it. If fuel pressure isnt in spec, now you need to see why. Fuel pump, filter, resticted line, bad reg, low batt voltage, bad relay, blown fuse etc. If FP is in spec, its time to hook up a noid light and verify our injectors are getting pulsed. If youre not getting a pulse you will want to hook up a scanner and look for RPM during crank. If you are getting RPM signal, check for spark. If you're getting spark and no fuel, although there is a commanded PW (see below) you probably have a bad ECM. How fast it cranks isnt as important as the fact you get a RPM signal. Next you'll look at Coolant temp to see if it coincides with ambient )if the car is cold), and verify TPS isnt shorted to Vref which will put the car in clear flood and cut off fuel. If these all look OK, you'll want to take a look at commanded PW.

3) If the car didnt kick, I'll yank a plug wire and see if I got spark. If I got no spark, then I'll check also for inj pulse using a noid light. If I have neither its usually due to a dead crank sensor. If I have no spark, but I have injector pulse, its usually a module.

See, its pretty cut and dry when you go back to basics of what the car needs. Air, fuel, spark, and compression. If any are missing, the car wont run. The hard part I guess is finding out what you DONT have, then finding out why. I guess I take my experience for granted, maybe it is difficult. Kinda like Me trying to learn or diagnose a Linux problem (Right Jeremy?)


Turn the key on. Look and see if the SES light is on.

If yes, listen for the "3 second" fuel pump prime.
With the key still on, bump the starter. Do NOT crank, just bump it. The fuel pump should prime for three seconds everytime.

If it does NOT prime, probably the cranksensor. MOST the time No spark/no injector pulse/no fuel pump prime (by bumping the starter) is cranksensor.
If you have a aftermarket tach crank the engine to see if the tach is reading. If the needle is moving it IS getting a ref pulse from the cranksensor. If no movement it is not (again usually cranksensor).
This will work with stock tachs also, but they are not accurate and hard to read this way.
__________________
A broken timing chain wont crank normally...see thats where listening to your car comes in.

You need to find out if you got no spark/inj pulse. Like Steve said, get a noid light and keep it in the toolbox.

Typically:
No start - no spark, has inj pulse -> Module
No start - has spark no inj pulse -> ECM / cam sensor prob
No start - no spark OR inj pulse - crank sensor or module

Oh, and if the module is dead, I suggest putting a coil pack on it as well as most of the module failure are caused by an overheating or arcing coil.
A broken timing chain wont crank normally...see thats where listening to your car comes in.

You need to find out if you got no spark/inj pulse. Like Steve said, get a noid light and keep it in the toolbox.

Typically:
No start - no spark, has inj pulse -> Module
No start - has spark no inj pulse -> ECM / cam sensor prob
No start - no spark OR inj pulse - crank sensor or module

Oh, and if the module is dead, I suggest putting a coil pack on it as well as most of the module failure are caused by an overheating or arcing coil.
Turn the key on. Look and see if the SES light is on.

If yes, listen for the "3 second" fuel pump prime.
With the key still on, bump the starter. Do NOT crank, just bump it. The fuel pump should prime for three seconds everytime.

If it does NOT prime, probably the cranksensor. MOST the time No spark/no injector pulse/no fuel pump prime (by bumping the starter) is cranksensor.
If you have a aftermarket tach crank the engine to see if the tach is reading. If the needle is moving it IS getting a ref pulse from the cranksensor. If no movement it is not (again usually cranksensor).
This will work with stock tachs also, but they are not accurate and hard to read this way.
 
My check engine light comes on, and I have good fuel pressure. I have searched the topic many times and it all points to either the crank sensor or the ignition module. Having replaced both I wonder if I picked up another one that was bad.

Thanks
 
Originally posted by milesengineer2
My check engine light comes on, and I have good fuel pressure. I have searched the topic many times and it all points to either the crank sensor or the ignition module. Having replaced both I wonder if I picked up another one that was bad.

Thanks

Did you put the crank sensor in the correct notch?
 
Actually I installed it properly and it didnt work. Listened to a procalimed Buick guru and installed it his way and it still didnt work. So I have tried it in both grooves still to no avail. I do know that the first groove, farthest from the plug is the right window though.
 
Tried a few things today. Checked the injectors with a noid light and nothing. No pulse at all. Still no spark. Hooked up my oil pressure switch. Still nothing. Are there any ways to test the ecm to make sure it works? Same question about the ign module.

I guess the next step would be to find a known working ecm and ign module and go from there.



Thanks
 
How did you check for power at the injectors? If a test light or voltmeter and you had no power there under any circumstances, I'd check the FP/INJ fuse as it probably blew when the injector harness burned by the EGR riser :-)

I am not positive, and am not looking at a woring diagram right now, but I THINK the FP/INJ fuse is also power for the crank and cam sensors. Dont quote me, and dont shoot me if I'm wrong, but I seem to remember it being so... (I'm gonna check it now)

Very common, and I didnt see you mention checking it anywhere.

<edit> Looks to be the ECM/IGN fuse which is the hall effect power supply, so maybe I was wrong. The INJ fuse shouldnt cause no spark, BUT the ECM/IGN WILL as its the modules power for the crank/cam sensors.

Here is the schematic for checking powers and grounds:
http://www.gnttype.org/techarea/images/wiring_images/ecm_turbo.jpg
 
Thanks Jim, actually fuses were the first thing that I checked, sorry I didnt mention that. All of them were good.

There is a no start schematic that was given to me in a previous post and that is how I checked everything.

Still lost, been screwing with it now for a couple of hours. I need to get ahold of some locals here and get a known good ECM and cp/ign module and see if that cures it.


Thanks
 
Update

Alright, tried an ECM and Ign Module/Coil Pack, (thanks Red Regal) and still no injector pulse or spark. So far I have changed the ecm , coil pack ign module, crank sensor and battery. Still same problem. Does anyone else have any ideas? I have tried the no start diagnostic on gnttype and everything pointed back to the ccci module or ecm and changed them still to no avail.
Does anyone know what wires are supposed to be hot to the ecm? I checked every wire on the harness and none have power, key on and off. I think this could be part of the problem.

Thanks

Lee
 
Re: Update

Originally posted by milesengineer2
Alright, tried an ECM and Ign Module/Coil Pack, (thanks Red Regal) and still no injector pulse or spark. So far I have changed the ecm , coil pack ign module, crank sensor and battery. Still same problem. Does anyone else have any ideas? I have tried the no start diagnostic on gnttype and everything pointed back to the ccci module or ecm and changed them still to no avail.
Does anyone know what wires are supposed to be hot to the ecm? I checked every wire on the harness and none have power, key on and off. I think this could be part of the problem.

Thanks

Lee

So you're saying your check engine comes on at key on, and you have 12v and ground at the cam and crank sensors? And still no spark or injector pulse? Hmm, time to start pinning out the harness I'd guess.
 
other than the crank sensor all voltage is fine, i'll check that later. is there supposed to be 12 vts at the computer?
 
Problem Solved

After some investigating, probing and obsenities I finally have the T-type running again.
Problem turned out to be three problems. The first was the computer was getting intermittent power from the battery due to a loose lead in the harness. Second was the connector on the battery to the ecm power wire was broken and loosing power when under a load.
Third and most importantly I went through three crank sensors to find one that worked. Two Wells and one delco. None of them worked. Finally got a known good one and the car started and sounds great.

Thanks to all of those that responded, I appreciate all the help. Especially thanks to Brett and his father, without them dissecting a running car to help me with the voltage reading on plugs I would still be chasing my tail. Good to know there are still helpful people out there.


Lee
 
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