Granddaddy of no start issues? Experts please come inside...

[machinegun]

I would agree sounds like a signal loss of some sort somewhere.

Where it is is the issue.

So where are you located? Anyone near you have a scanmaster, direct scan or OTC?

I would ike to know if there are any weird tach readings at the ECM. It seems weird that it all dies but the pump is still running.

Something you could try, get a noid light install at a place you can see. Start the engine and see if when the car dies does the noid stop flashing?

Another item, have you brought the engine speed up some before the engine stops and if so dies it hesitate or just die?

Does it restart immediatly?

One more item, have you checked the ECM socket and Engine wiring harness plug for an loose wires, connections, pins or corrosion?

 

[Attype]

Have you checked the fuel quality yet? How old is the fuel?

 

[need boost]

pull the intake hose off in FRONT of the maf, look inside it . The screens that are there make sure they have not turned and the clip is holding them flat. If so take them out and look into the maf to make sure there is not a bug or such on the inside. I know that sounds stupid but LOOK. Mine did almost this exact thing and my clip had popped loose and the screens turned touching the inside of the maf. Was making mine go crazy! If that is all good grab your cam sensor and try to turn it just a hair either way. My bolt had worked loose on mine one time also and it doesn't take much to throw the timing off crazy. Also unplug the cam sensor and look inside the plug for corrosion on the plug ends. If clean put a little dielectric grease on it and push it back together.

 

[Jerryl]

Did you figure this out?

 

[turbo39151]

Sorry, no... Been out of the loop for a while. Flew home to see about ill family member. Should be back next week and the fun will begin all over again.

Don't worry, I'll be back complaining in no time and will not let this thread die without resolution. (I hate when people don't follow up)

Hope everyone has a great turkey day.

 

[turbo39151]

OK, I'm back.....

Got back a few days ago. Finally had time to get back into the car today.... Decided to start over and re-trace my steps...

Pulled the new cam sensor. Checked and double checked my TDC and 25* and re-installed the old cam sensor (It was fine).

Re-checked all the sensor connections.

Installed plugs.

Tried to crank - Same as always. FP still great.

Swapped some new Taylor 10.5 wires I got from Brian at g-body--- still no start and now, finally, a dead battery! (can't win)

Gonna try and find a battery charger tomorrow and am gonna sit down with the "boss" later and see if we can start tracing all the wires using the GM Service manuals and schematics when she has some time... (She was ASC Certified in Auto Electronics a few years ago--- Just a matter of having time..)

Still considering the power logger but not sure if spending $265 for this is going to get me any further.... If anyone has input on the tool, please advise. I've always used the scan master with great success and really hate to spend more money if it's not going to be very useful for my application.

I'm also wondering more and more if this is just a matter of weak spark. I had some credit with Nos4gn so I ordered a new coil pack- Pulled my old one apart from the ignition module (It's the original 86 part). One of the screws broke off in the ignition module. Sheared right off just short enough I can't grab it. Considering that that unit is original equipment, I've been thinking it might be a safe bet to buy a new module... What do you guys think?

As always, any and all input is welcome...

 

[TurboBuRick]

Did you replace the crank sensor yet?

 

[turbo39151]

Yup. Put a brand new one as one of the first things to diagnose...

 

[Gnology]

Im interested in what's happening at the injector. I would try turning the key to prime the pump, before cranking unplug the fuse to pump. Try cranking, this should limit the amount of fuel "dumped" into the cylinder. If it runs then dies, try again and have someone plug the fuse in after it starts. Next i would listen for the injectors clicking during cranking. Another thing I would try would be cranking while holding the pedal at 1/4 to 1/2 throttle to introduce some air into the equation.

 

[turbo39151]

Gnology: Thanks for the input. I'll be checking that next.

Battery had died. Finally got a good charger and discovered a bad cell. Battery only at 11.85v.
Swapped out battery for brand new one 12.66v. Tried cranking just for gee whiz and still the same symptoms.

Starting to get frustrated with this issue. Might need to bring in a fresh set of eyes- before I throw something.

 

[TurboBob]

I want to go back thru the whole thread, but..

When we were working on the new ignition system, we discovered a wierd failure mode.

If the bypass signal from the ECM does not work properly, the ECM will shut off the injectors after running for a second or so.

So, it might be worth checking.

Bob

(We are building diagnostic trouble codes into the new ignition system to detect stuff like this along with sensor issues.)

 

[turbo39151]

turbobob: Thanks for the input. I will see if that is something I can check. Sending you a pm...

 

[machinegun]

Hey if you are near me you are welcome to my direct scan.

If not I can ship it to you so you can use it.

I can send the hardware, application for you.

You will need to find a laptop that you can boot to dos mode to run it.

Let me know.

 

[turbo39151]

machinegun: Thanks for the generous offer! I have contacted a local guru who will be stopping by my place next weekend. I hear lots of good things about him and have spoken with him as well... I think just getting a fresh set of eyeballs on this will help alot. It is probably something stupid that I have overlooked and continue to overlook... Makes me crazy to not be able to find the problem myself but sometimes you just need to know when to ask for more help.... Thanks again for the offer, if I need it, I will get in touch with you.

 

[Rafs-T-Type]

The suspense is killing me! I can't wait to hear what the problem is.

 

[jimski]

Does the chip have anti theft in it? It is probably disabling the car

 

[turbo39151]

theraf8100: suspense is killing me too! LOL
jimski: Just a standard TT chip, no anti-theft that I know of...

 

[Razor]

A few years ago I helped a buddy with a no start and on his the wires where pulled on the crank sensor. The copper was broken below the insulation and not allowing continuity.
Triple check that plug and wiring to it

Julio

 

[SloGN]

Just cause the coil checks good by ohming it out . It can still be bad. Try swpping it out on another car

 

[TurboBob]

...........Kind of like if you were to turn the key on, have the engine sort of start and then you turn the key off... Problem is that it seems to catch and kind of start but won't... I have not seen or felt the key come back to off. I may have to look at the ignition switch...(However, it has started, albeit briefly, while doing some of these tests...)

.......

A quick video might be helpful here. Most of the times I hear "no start", I assume the car is just cranking with no fire. But in your case it sounds like it fires briefly and then shuts back off.

So its more of a no-run situation, than a no-start. About .5 sec after "starting" then ECM switches things from "cranking mode" to "Run mode". Cranking mode delivers fuel from a very basic calculation. Run fuel is delivered based on airflow. Cranking spark is controlled within the ignition module, run spark is controlled by the ECM (the ECM sends trigger pulses to the ignition module)

Did you check continuity and ground on the EST and Bypass wires from the ECM to the ignition module yet? Since you have swapped every module and sensor, you need to start verifying that wires are not broken or grounded. I believe a grounded EST wire will cause this exact symptom.

Bob