Need help troubleshooting no spark condition

[detailer4u]

I have visited this forum so many times in the past and I'm glad I finally signed up. I have a 1996 Astro cargo van that I use for my auto detailing business. I purchased the van almost 10 years ago with only 17k miles on it. I am notw up to 118k miles and looking forward to several hundred thousand more. It is very well-taken care of and I drive it conservatively and take extremely good care of it - and even get 21.9 mpg from the Vortec! Oil changes never get forgotten and being a detailer who loves the business, the exterior looks just like new - this van stands our from all the other Astro cargo vans that get abused as business vehicles.

Two years ago the alternator went bad and I replaced that, the belt and battery.

Last year I replaced the radiator

After hitting the 100k mile mark and STILL going faithfully every time I started it up, I knew it was time for a major servicing because nothing will last forever and I want to stay one step ahead of breakdowns - or at least try. So within the last few months I have installed/replaced the following:

Wheel bearings and brake rotors when the last set of brake pads wore out

Old vacuum lines

All four shocks

Headlights and all exterior bulbs (they were operational, I just wanted new ones)

all 4 oxygen sensors (they weren't bad but should be replaced at 100K anyway)

Spark plug wires

Spark plugs

Ignition Coil

Distributor cap and rotor

Cleaned EGR valve (as I do regularly)

Cleaned Intake Air control Valve (as I do regularly)

Cleaned PCV Valve

Replaced all coolant hoses and the fitting that feeds the heater core hoses

Power steering pump

Transmission filter and fluid change

Oil changes are done about every 3 -4K - no more than 4k. Every couple changes I sub 1 Qt of Marvel Mystery Oil

Air filter is always replaced as needed

Fuel filter

I'm sure I am missing many other little parts I replaced but you get the point. Here's the issue I am currently having: I planned to replace the leaking lower intake gasket with the Felpro upgrade kit and in the meantime I had two lifters collapse (it was loud and obvious) I was out of town and still made it another 350 miles home - no bent push rods, no engine damage. So as soon as I returned home I parked it and stopped driving it and ordered the Felpro kit wich I was glad to see also came with new valve cover gaskets. I replaced ALL the lifters and both push rods from the failed lifters because the push rods had some minor damage from the lifters. While I was in there, I also replaced the spider for good measure - I already had it apart so why not - that's good insurance to not have to open the engine back up any time soon.

After the engine was put back together it started up, ran for a minute and died. It would run, then stall every time. This van has never done this so this was very unusual. I was careful with every electrical connector and actually removed and cleaned the ribbed water seal on every conector with Isopropal alcohol so it would dry quicly and I could reconnect quickly. I have an electronics degree - I know about water and electricity, therefor the IPA choice. I took photos of everything before we took the engine apart and we (my dad and I)had no issues with reinstallation and as always, we had no hardware left over and all tools accounted for.

We discovered the we had the timing off, so we re-adjusted for TDC and got the timing right. From that point on, the engine will crank so the starter is working but I have no spark coming off the (new)ignition coil wire. I don't mind replacing parts on a vehicle with miles on it so I replaced the Ignition control module and the crankshaft position sensor and still have no spark. I tested the new ignition coil just in case and it's still good.

The battery is showing 12.5V and is 3 years old. Just to try, I jumped it to another vehicle while the other vehicle was running - still no spark in the van. The fuel pump was replaced 4 years ago, I can hear it working when I turn the key and we can smell fuel getting to the engine and confirmed that by removing a spark plug that had fuel on it - plus I just installed another fuel filter about 4 weeks ago.

I have checked all the electrical connectors for isolation from ground and they are all good and receiving proper voltage. I have battery voltage at the connector for the ignition coil, camshaft osition sensor, ignition control module and crankshaft position sensor (all 3 parts are brand new), 5V at MAP sensor, etc. I am suspecting the computer at this point. The camshaft poition sensor, as I understand it, will not prevent the engine from starting if it goes bad although I did remove it, clean it and replace it yesterday.

Has anyone had this problem? Scrapping the van is not an option - I have outfitted it specifically for my business so it's a one of a kind that cannot be replaced. I have put too much time and effort in to taking care of it and preserving it and hey, I'm a detailer - it looks like new, inside and out AND the engine bay as well - I actually wax the paint in the engine bay and all non-porous parts around the engine on a regular basis. I love this van and refuse to give up, I'm going to fix it but I need your input.

What else could cause a no spark condition? My dad and I have rebuilt 3 other GM engines (it's all I drive) and do all our own repairs without incident but this one has us stumped. Has anyone heard of a starter operating but shorting internally and preventing spark? This van has been extremely reliable for almost 10 years and has always run GREAT! I need to get it running ASAP - I have customers waiting!!!

Your input is greatly appreciated.

[chevymaher]

Sounds like a no fuel rather than a no spark condition. Check the fuel pressure before during and after start. Sounds like the oil pressure sender or connection there is the culprit.

[detailer4u]

Thanks chevymaher, I have enjoyed reading so many of your posts before signing up. You know what you're talking about and I like your informative lenghty answers. We do have fuel, we can smell it and I pulled plug#1 and it had fuel on it. I am troubleshooting it right now (laptop outside on makeshift desk!) but will look into oil pressure sender connection. I thought about measuring fuel pressure just to confirm - good idea. I have the intermittent ABS light issue so I may pull the computer just to check for cold solder joints. I've been wanting to do that anyway and a new computer isn't that expensive for this thing anyway.......I'm going to keep searching until it's fixed. Thanks for the input.

[detailer4u]

I always have good oil pressure usually around 45lbs, sometimes a little more. What would be the proper way to check/test the connector? Just put a meter on it and have 12.5V (battery V) at the connector both with key in on position and key out.

[detailer4u]

OK, I found out that the oil pressure gauge should peg all the way over when disconnected and when coonnecting the negative connector wire to ground and that's what happened. I suppose we can call that good. I'm geting close to pulling and opening the computer to check the internal solder joints.

I'm running out of things to try...any input is welcome...I'll try it. Thanks!

[Herman Wiegman]

I am not sure your 1996 has the oil pressure switch in line with the fuel pump. I think that was phased out a bit earlier. You can check the number of wires going to your oil pressure sender on the back side of the engine below the distributor.
I think your oil pressure sender will have just one tan colored wire. if this is the case, then there is no oil pressure switch in line with your fuel pump.

How do you know the engine is not producing spark?
Do you have a timing light? or did you put the spark plug on the outside of the block?
Good that you got back to TDC and did the Distributor alignment trick. I also did this and my timing is back to normal.
Can you install the old spark plug wires and the old cap and rotor?
Do you hear any "ticking" noises when it idles? This could be arch flash from a faulty component in the distributor/coil system.

You mentioned that you changed the fuel spider and that you are smelling fuel. (Alarms are going off for me! you should not smell fuel at any time... you could have a leak into your intake plenum.)
Did you change out the two o-rings which go around the two metal fuel lines which connect to the top of the injector assembly? That may be a location for a fuel leak, which is dropping the pressure to the engine's injectors. (the fuel pressure regulator is "down stream" from those two o-rings)
You can check this by removing the dog-house and peeking in that region with a shop light and a dry paper towel.

Did you get all the PCV stuff back together well? Do you hear any air leaks? That could also stall the engine out after a few seconds. note: the PCV hose has two clips which are fragile and you need to push these "in" to disconnect them.

Walk us through a re-start procedure... what happens in which order?

Keep on trying,
Herminator

[detailer4u]

Oil pressure sender is located on the back of the engine on this one.

No Spark: when it wouldn't start I decided to remove plug#1 and hold it outside the engine and tried to start it. No spark. Next I went to the ignition coil wire, disconnected it from the distributor and attempted to start it - no spark from the ignition coil wire. We did have good strong blue spark two days previous.

Yes, I replaced the orings on the fuel lines and coated them with a thin coat of oil per the instructions - those are the supply and return lines with the fittings located under the distributor - driver's side. Where both fuel lines enter the top of the spider connector had "built-in" for lack of a better word deals and they each fit into their respective hole tight and snug. There were two other O rings in the kit but one was way too big and the other way too small to have gone to the top fittings.
You have me wondering about the fuel smell.....I have had the doghouse off for a couple weeks now as I troubleshoot this. I 've had it off before and never smelled fuel but then again it was being combusted. If there is a fuel leak, could the drop in pressure make the computer not send signal to produce spark? I have battery voltage at the ignition coil and control module but no spark coming from there.

Yes the PCV connectors are all back nice and tight. I was very thorough with everything as I always am but I will go back over and double check everything - it certainly can't hurt.

Stand by, I'll send a restart procedure.

[detailer4u]

Basically we replaced all the lifters, two of the push rods and then the already planned manifold gaskets, plus the valve cover gaskets. We removed the lower and upper manifolds separately but for ease of reinstallation, I installed the Throttle Position Sensor, Intake Air Control Valve, etc, for easier re-installation. My dad and I went through about a dozen trail runs with the upper and lowe together before final install. I squeezed a more than sufficient bead of RTV on the front and rear of the block for the RTV to set onto. All surfaces were cleaned with Acetone and any old gasket material removed prior to re-installation. I am a cleaning fanatic so everything was thoroughly cleaned, dried and prepped before we put it back. We got a nice ooze out of the lower manifold and let it sit for 24 hours before attempting to start it. First try it started right up then died. It would start up but then die shortly after. Then we wound up where we are not - no start at all and no spark. I checked all the wires in the harness arouns the back side of the engine for isolation to ground and they are all good and all have their respective voltages. I have done continuity checks on a few components to try to find something out of the ordinary but cannot.
I did try jumper cables from my dad's car to my van to help charge up my battery and tried starting it off his car with engine running - with V drop across the cables I still had 13 - 13.5V on my dash and no spark.
I am about to open up the computer.
Oh and I had a friend who is extremely talented with cars look at it yesterday and he was stumped.
Also, there were three codes but they were from when I had to start it to move it around the driveway during a couple recent sensor swaps and I'm confident they aren't related to this.
There was a P1351 code and I believe that was because we recently tested the Ignition Control Module and it failed the test. There is not a lot of definitive info online about the 1351 code and it's not listed in the manual I have.

You have me interested in where the fuel smell is coming from. I may try to start it to get that smell back and see if I can locate the source - and again, the doghouse is off until it's fixed.

Thanks so much for your input it is much appreciated. Thhis van is very well-taken care of and maintained so it's a little frustrating and shocking - in almost 10 years I've had it, it has NEVER let me down like this - this van is Old Faithful but I need to figure out what's going on. Thanks again.

[detailer4u]

FYI, I have my laptop out in the driveway...will be working on it for another hour or so then I have to stop for the day...will pick up again tomorrow.

[binder]

If you are not getting spark and the coil is OK and it is not a sensor, it is may be the ignition control module. You may have bent a wire or partially disconnected it while doing the valve job? or it might just be starting to go? I think they can behave oddly, in that they sometimes work and sometimes dont, even if they check OK.

Though that it happened after you did the valve job, makes me think some bent wire or connector.

[Leeann_93]

I am not sure your 1996 has the oil pressure switch in line with the fuel pump. I think that was phased out a bit earlier.

That wasn't phased out until '99, so his fuel pump does run through the oil pressure switch.

I'm more interested in the ignition switch. It started, ran for a little bit, then cut off and won't restart. Does the '96 have the Security light on the dash (aka Passlock II)?

[detailer4u]

I've never seen the pass lock or Security light - probably because this one is a cargo version.

I have replaced the ignition coil, ignition coil control module, crankshaft position sensor and the list goes on......most of those were just due to the long list of parts replaced as part of a big tune-up and just trying to stay one step ahead of breakdowns - trying to replace sensors or small parts that could strand me. This van has never given my any grief....this is just weird.

Thanks so much for the input.....keep it coming. I am acting on everyone's input because I may stumble upon the root problem while checking something else.

I was very careful with the wire harness and sub connectors on the back of the engine because of their age and I did continuity checks and they check out OK

I just tried to start it to get some fuel up front to see where the strong fuel was coming from and couldn't really pin it down. There was a very strong fuel smell coming from the exhaust pipe but that's no surprise.
I made sure the connector at the top of the spider was seated all the way up and as far as I can tell it is and I did apply a light coating of oil to that before installation per the instructions.

Still no spark.......Thanks again and keep the ideas coming no matter how crazy they may seem!

[detailer4u]

Oh yeah, I did check all connector pins and they are all straight. No ticking - the distributor cap and rotor have all been recently replaced. Distributor gear is good. Had a little ticking when it initially did start but that was because I replaced all 12 lifters and even though I soaked them in oil for 48 hours before installation, they took a minute to fill with oil and they quieted down quickly.

[Herman Wiegman]

Ok.. the lack of spark is the number one issue right now.
And I second the comments about bending wires and having a potential issue with a break (when it is plugged into the proper place). I know the wires to the top of my ignition coil unit have an awkward bend when they are finally in place.

Your test of a spark plug on the main output of the ignition module (and lack of any spark) seems to indicate that it is not electrically being triggered, or it is unable to produce a spark.
You have checked the low voltage and high voltage coils for continuity (or resistance value), so that seems to indicate the physical coil is ok... but you may want to swap over to a spare unit just for kicks. (the resistance reading may be reasonable, but there could still be an arch path internal to the device which shunts the spark before it goes out to the distributor).

The other critical piece to the puzzle is the hall effect pick up sensor in the base of distributor. The wires and the sensor here are critical to the development of spark. Inspect them carefully.

You could also try starting your engine (with the ignition coil feed wires unplugged, and with the distributor cap off), and see if the rotor is turning.. the drive gear has been known to wear or break.

After you get your spark going, you may still have to solve a fuel leak issue.

Herminator

[detailer4u]

Thanks for your time and input Herminator. We are certainly eliminating potential issues here.

I did check the wires and yes the connector to my ignition coil is tight too - the could have just given us a nother inch or two of wire, you know?!
I checked the wires and they all appear good and I have proper voltage at all the connectors. My dad and I even put a meter on them while checking continuity and wiggled them while I attempted to start the van - no spark.

I have checked the ignition coil and I do have a spare and with both coils - no spark. And of course the ignition control module was replaced on Friday.

We tried to pinpoint the source of the fuel smell before I stopped yesterday. I stuck my nose all over the engine - especially the fuel supply and return fittings on the driver side under the distributor and could not get a strong smell anywhere. I even too a small piece of tubing and used it as a sniffing device for specific areas. I confirmed that the connector/spider top is indeed sealed good. What we did find is a STRONG fuel smell coming from the exhaust pipe and I think the fumes have been coming around and it makes sense because we would always smell it after several attempts to start it. I suppose that's just normal because fuel is getting pumped and not combusted.

I did not check the Hall Effect sensor/wiring. I will do that shortly when I go back out to the van.

The rotor is turning, we took the cap off and did that on Friday

Also, I was wondering, I have a direct connection to ground from the square "frame" around the ignition coil.....does anyone else have that. Unless your dog house is off, I don't think you could test it but has anyone else ever noticed that? I don't think it's an issue because I don't see a short via checks with my meter but I cannot rule anything out at this time.

The Hall Effect sensor is a GREAT idea, I saw that in the manual and we didn't check it yet. We are very careful with any parts and components and were especially careful when the distributor was removed. That's one thing I really like about working on the cars with my dad - like me, he treats parts like they are eggs.

I am also going to re-check all the wires. Keep in mind the van did start several times after we put the engine back together. Then it stopped.

Thank you, Thank you , Thank you for the suggestions. Each idea is one step closer to getting back on the road.

During the day, I run my detailing business and at night I work a full time position as a Lab Tech Specialist in aerospace building and testing telecommunications satellites. We build satellites, for example, for Direct TV, Dish, Sirius/XM and telecommunications/cable companies around the world. Prior to that I worked onclassified space programs for 8+ years. I have plenty of electrical/mechanical experience and training with that and have built custom wire harnesses, I've obtained NASA solder certification (80+ hours of solder training to obtain that) and on and on for satellites and all but man, this issue with my van is making me really think!! LOL, We'll get it - eventually.

Please keep the suggestions coming, your time spent posting and Astro/mechaincal knowledge are greatly appreciated!

[detailer4u]

The Hall Effect Sensor....that's basically the camshaft position sensor, right? It's the 3-wire connector that plugs into the distributor near the 8:00 position, right? I have never had to test one. I'm dong a little research to find out but if anyone has any input/procedure for doing that, your input would be appreciated.

I failed to mention in my last post that both of my ignition coils are new and tested to to be absolutely sure they are not defective new parts. The first one I just replaced when I recently did the spark plugs and wires so it's just a couple months old.

[detailer4u]

Ok, here are some thoughts that came to mind: since I have proper voltage to the connectors (I have measured that several times to triple, quadruple check, etc) would it be a safe assumption that my wires are good throughout all the circuits? I did pull back the flex loom on all the cable bundles on the battery side a few days ago and found no burned or corroded wires or anything that look suspicious.

I have battery Voltage at Distributor connector (Cam sensor I'm assuming), Ignition Coil, Ignition Control Module, Oil Pressuer Sending Unit, 5V at MAP sensor with key in on position.

Also, the Chilton's manual states that if the Camshaft Position Sensor goes bad that the engine will still start but the check engine light will come on. For that reason, I have been eliminating that from the cause of my no-spare issue. We have found a couple things in that Chilton's manual that are not correct.... I just went out and took some measurements to compare with info I get to test it and from the + to - on the sensor I measured 1556 ohms. Should there be resistance across those pins?

[Herman Wiegman]

Yes, the "camshaft position sensor" is at the distributor (which is driven from the cam shaft).
This device needs to be fed 12Volts (pink wire), and two signal wires (brn/wht , drk grn) where one is probably ground referenced, and the other oscillates between logic low and high. These two signal wires go to the Vehicle Control Module.
Check fuse ENG-1, MiniFuse F7 (in the under hood fuse-center) which feeds both the camshaft position sensor and the ignition coil. This pink wire should be 12 Volts with key in "run" or "start" positions. (it also feeds the EGR valve and the O2 sensors, so plenty of reasons for this fuse to blow).

If you can get a volt meter on the ignition control module wires while trying to start the engine, you should be able to cut the diagnosis problem down to size real quick.

The Ignition Control Module has 4 wires...
1) Black (or tan) = ground
2) Pink (Fuse7) = 12Volt feed
3) White = timing signal from Vehicle Control Module (tells when to trigger a spark)
4) Wht/Blk = output to the coil (to generate the spark)

If wire 3 is low all the time, then the culprit is upstream of the Ignition Control Module
If wire 4 is low all the time, and wire 3 is switching up/down, then the issue is with the Ignition Control Module
If both wires 3 and 4 are switching between ground the 12V, then look down stream at the ignition coil and distributor.

(note: the trigger signal may be a very quick pulse to 12V, so the volt meter may only read a very small average voltage signal above ground.. so it is better to put an oscilloscope on if you have access to one... or do a voltage reading before starting and compare against that when attempting to start.)

good luck,
Herminator

[detailer4u]

Thanks Herminator! OK I just came in from some more electrical troubleshooting and probing. I wound up figuring out that the camshaft position sensor was the one on the Distributor.

I have the proper voltage at the camshaft sensor and all other connectors with key in on position.

I have checked ENG 1 fuse and it's good. I actually checked every single fuse in the van just to confirm that something stupid wasn't going on and they're all good and we aren't blowing fuses either.

Having just spend time looking at the wiring diagram I have, I did see that the power wire is indeed connected to multiple other sensors. I just replaced all 4 O2 sensors and part of a big preventative maintenance "campaign" and I cleaned the EGR valve while we had it all apart. I'm done for the night but I will check electical at the connector to the EGR just to make sure everything's good first thing tomorrow am when I'm on it again.

I checked the ignition control module for continuity to confirm that I don't have any broken wires. Ihave continuity from the red all the way to the ENG1 fuse and the black to ground is good as well. Also the white/black signal wire that goes from the ignition coil to the ignition controller has continuity.
I also checked the ignition coil pink power to ENG 1 fuse and have continuity

You saved me a lot of time because I cam inside to look up a proper procedure for how to check the signal to the ignition controller! I will be doing that first thing tomorrow.

I think I may want to test the signal wire from the crankshaft position sensor too. If I have issues, I may pull the connectors at the computer and check for continuity from the fuse box to the computer connectors for the respective wires.

I am starting to seriously suspect the computer. I was going to remove it yesterday but I wanted to leave it in so I could do some more testing and I'm glad I did that. If the bove test fails, I'm pulling the computer. I already disconnected and inspected all the connectors on the comupter a couple days ago and everything was clean and no burn marks - it looked perfect.

I don't own an Oscilloscope but if needed, I know someone who does.

Thank you so much for taking the time to send me all this information. It is a great learning experience and I am learning more specifics about my van (mechanically) that I would not have otherwise discovered. I hope I can return the favor to you and many others on this forum in the future.


I'll post the results tomorrow.

[Jasen]

tossing this out there. we've seen here cases of the coil lead wires corroded without any outward visible signs.