1985 Z28 with 350/auto. Car was running fine then began to sputter and backfire. Now it will not start. Even with starter fluid there is no start. Parts I've thrown at it: New plugs, wires, distributor cap, rotor, throttle control unit. I had the engine control module(? half-moon shaped deal with 2 contacts on each end under rotor) bench tested at O'reilly's. Fuel pump is new Bosch unit and I have about 40 lbs at rail. Even the starter is a new OEM Delco unit. What am I missing? How do i trouble shoot this issue? I tested spark with a tester set at 30K and it showed no spark. Any help would be greatly appreciated.

 

I think I would start by checking timing. The backfiring is most often a timing issue. Its pretty easy to do and takes a couple min to do so its a good starting point. With 40 at the rail, and if you have confirmed there IS spark AT the plugs there isn't too much else that could cause this problem. I don't recommend "ear" timing because there's too much room for error and you will never get it right. Make sure you disconnect the timing connector by the a/c condesor on the fire wall when trying to adjust timing!

 

Thanks, but the first issue I believe that needs to addressed is that there is NO spark.

 

Oh, I missed where you said no spark- sorry. How many times did u have the icm (ignition control module) bench tested? You can't just have it tested once, I always have it tested at least 5 or 6 times. If it fails intermittantly it may not fail the first few but chances are it will by the 5 or 6 time.

If you have no spark at any plugs there's a number of things it could be, what I would do is start by checking to make sure you have power to the coil. I'm not sure how far you have diagnosed it but I would start by doing this, then working your way thru the distributor, making sure you have power to and from each part. The most common supects in this case are pick up coil, coil, icm, and possibly esc.

 

LEAVE THE TIMING ALONE!!!

It doesn't just all the sudden out of the clear blue for no particular reason, just UP and WACK itself out into the ozone BAD ENOUGH to cause that.

All that you will accomplish by messing with it is, you'll have JUST ONE MORE THING you'll have to go back and fix, once you find THE ACTUAL problem.

You have some sort of electrical problem. I'd suspect, at this point, from your description, pickup coil.

 

To replace pickup coil one has to remove the distributor correct? Can the pickup coil be tested before pulling distributor? I'm going to replace the control module just because it should be changed. Is it a good idea to just replace the entire distributor? I have never done this procedure, but what the He//, I want this car to run. If I pull the distributor I might as well replace for a better/newer unit, right? Any suggestions for a replacement?

Is there a procedure to trouble shoot the system on the site? I'm not very experienced so a guide would be helpful. I'd hate to give in and have it towed to a shop. Just because!

 

I think I need to replace the connectors inside the distributor. Can anyone tell me where to order replacement connectors?

 

Yes, to replace pickup coil dizzy must come out.

As far as replacing it with an entire aftermarket unit, that's your choice. If it were me, i would just buy a quality (msd, accel, mallory, ect) cap rotor 8 or 8.5mm wires high performance coil and new plugs (obviously a new pickup coil) and call it a day. Its probably cheaper to buy that way if you shop around than if u buy a new unit altogether.

 

You can check the pickup coil's resistance (should be a few hundred ohms, maybe between 600 & 1500 or so with most of em around 750 - 800), but there's more that can go wrong with it, that doesn't show up that way.

If you can trace the problem to the dist, and that's a likely culprit, replacing it whole is probably as good an idea as any.

THere's not many connectors in there... you can get the one with the pink/blk/brn wires at the parts store, and maybe the one with 4 wires that goes to the computer, but all the others are part of something else.

 

How hard is swapping out the distributor? Any special tools needed? Any tips or tricks I should know? Also please recommend a good replacement. I don't need super expensive racing equipment, but wouild like a good solid replacement.

 

before changing the dist I would highly recomend the ignition coil be tested . this is a more comon problem than the dist. I hate to say it but I have to agree with foamy dude this time this is a very familar sounding issue . happened on a few of my camaros.

 

I replaced the coil with no results.

 

why would you buy aftermarket? he doesn't need that stuff. Stock ignition products are fine. Listen to sofakingdom.

 

Why not? I guess if your not looking for a little better performance stick with stock. Stock does work fine. I always try to do a little better than stock when possible. If you have the money and don't care for better parts, better performance and better fuel economy stay with stock. Your choice-your car. I hope you get your problem fixed.

 

I say that because, he has nothing to back up the need for higher voltage or better ignition parts. Most cases I have seen, the car ran better with the stock stuff.

 

So the consensus is that I should stay with a stock system? The ignition system is not something I'm knowledgable about, but I see all these offerings of higher voltagesystems. What would be the benefit if any? Thanks again for the input.

 

https://www.thirdgen.org/forums/afte...ox-advice.html
Here's an example. I personally would save the money for other stuff. At a basically stock vehicle, I wouldn't really bother.

 

check the codes first!!!!