1997 Safari. won't start. has fuel, spark, compression...

[terhotq]

Hey all,

I have been trying to figure this out for a while. My 1997 Safari won't start. It cranks fine but won't fire. Fuel pressure is good, compression cold was around 120 psi, and will not start with starting fluid or carb cleaner. It seems like an ignition issue. I get spark to all 6 cylinders, and it looks like a strong spark. A brand new AC Delco cap was put on. I can get the motor to sputter if I hook the coil directly to a spark plug wire. This would seem to indicate an ignition timing issue. Mechanical timing seems to be on (crank damper mark at tdc, ignition rotor point at #1).

What can cause ignition timing to be off? What can cause too weak of a spark? There were no fault codes, and the coil resistance checked out OK.

My guesses are bad plug wires, bad coil or bad crank position sensor. I really don't want to be guessing though. Any help would be appreciated.

[Blue Bowtie]

Do you have a timing light at your disposal?

[terhotq]

Originally Posted by Blue Bowtie

Do you have a timing light at your disposal?

Yes, and I tried to verify the timing while cranking. When #1 is at tdc, it is impossible to see the mark on the crank pulley, so I set #2 to tdc, highlighted the timing mark on the crank pulley, and noted where it lines up in relation to a certain location on the block. The timing light would flash very near this point when I cranked. It seems like the timing should be very close. I have also removed the clamp from the distributor and rotated it while cranking.

The only way I ever got it to even sputter was by joining the coil wire and one plug wire together and then cranking. This worked on every cylinder. Apparently I am getting fuel and have enough compression. Could it just be a very weak spark? Spark at the plugs look decent when a plug is pulled though...

This has me pretty stumped...

[Airjer_]

I think it would be a wise investment to purchase a variable gap spark tester. This will eliminate the guess work on whether or not you have enough spark. If the spark is week than the two things I would suspect is the ignition module (just had one last week with weak spark) or the coil.

[terhotq]

Originally Posted by Airjer_

I think it would be a wise investment to purchase a variable gap spark tester. This will eliminate the guess work on whether or not you have enough spark. If the spark is week than the two things I would suspect is the ignition module (just had one last week with weak spark) or the coil.

Does the CSFI motor from 1997 have an ignition module? If it does, where is it located and how can it be checked?

I check the coil resistance per the Haynes manual, and it checked out OK.

A friend of mine has a variable gap spark tester. I will see if I can borrow it from him.

[terhotq]

Originally Posted by Airjer_

I think it would be a wise investment to purchase a variable gap spark tester. This will eliminate the guess work on whether or not you have enough spark. If the spark is week than the two things I would suspect is the ignition module (just had one last week with weak spark) or the coil.

Does the 1997 CSFI motor have an ignition module? If it does, where is it located and how can it be tested?

The coil passed the resistance checks per the Haynes manual.

A friend of mine has a variable gap spark tester. I'll see if I can borrow it from him...

[drew300]

Just a suggestion - replace all the plugs, hopefully with known good ones. (Like good used ones - I always keep a used set around)
I did a tune up years ago only to find that all 4 new plugs were bad in a 4 cylinder car.

[terhotq]

Originally Posted by drew300

Just a suggestion - replace all the plugs, hopefully with known good ones. (Like good used ones - I always keep a used set around)
I did a tune up years ago only to find that all 4 new plugs were bad in a 4 cylinder car.

I did put brand new plugs in as well; I forgot to mention that. Can new plugs ever be junk, depending on the brand? The plug wires I have are not in good shape, so I may try that next.

I like the idea of keeping a good used set around.

[Airjer_]

The module is in the distributor under the rotor.

[drew300]

Well, you've got spark to the plugs, and it won't run on starting fluid. Something's stupid.
When I get stupid problems I look for stupid answers.
I've bought a total of 10 plugs from 1 company, and 8 where bad.
A friend, with the same make of plugs had them work fine until he flooded the engine ONCE, then it wouldn't start on those plugs after. Old plugs solved the problem.
If it ran on the old plugs you know those work. It's a cheap try, if a bit of work.
"when logic doesn't work, think stupid"
And new parts have a warrantee, in case they're bad.

[Blue Bowtie]

Since the timing is apparently close to correct, there is a source of fuel (starting fluid, or whatever), there is compression, and there is apparently spark, it must be running and you're just not noticing.

The timing light and fact that there is compression should reveal the condition of the timing chain.

I'd be somewhat suspicious of the spark energy at the plugs. A gap type spark tester might be a worthwhile investment, or perhaps you can borrow one.

[57Vette]

Install a new coil, and solve your problem.

[kenz65]

terhotq...did u figure out the problem with ur safari ?

[terhotq]

Originally Posted by kenz65

terhotq...did u figure out the problem with ur safari ?

Yes. It turned out to be a bad ignition control module. It is located next to the ignition coil on top of the passenger side of the intake manifold. IIRC, they share a bracket.