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distributor

lazydragon

NAXJA Forum User
Location
Buena Park, CA
Replaced distributor in 1989 cherokee laredo 4.0 i'm pretty darn sure I did everything right, but now I can't get it to start. it turns over normally, but won't fire. any suggestions?
 
True - but bear in mind that there are two TDC positions in a cycle - TDC Exhaust (actually, both valves are open - the intake is opening, and the exhaust is closing) and TDC Compression (both valves firmly shut.) Since the TDC mark on the HD up front only references #1 TDC (and not which TDC...) it's quite easy to get the two confused. It's worth checking.

Hell, I've gotten them crossed myself a few times, and I've been doing this for about 25 years...
 
it turns over strong. no blow back or rough noises. sounds completly normal, just won't fire up. could it be that the spark gap is wrong? they are at 035. what about a broken plug wire? i did spray alot of intake cleaner, but it's been two weeks since that was done.
 
Remove the air tube from the throttle body, hold your hand about an inch over the top of it, and have a helper crank the engine for a moment - that checks for air.

Remove a spark plug, crank the engine, and see if you have a fine mist shooting out of the hole - that checks for fuel.

Take the spark plug, put it in the distributor end of the ignition coil lead, and hold the shell against the engine. Crank the engine and watch the plug gap. This checks for spark.

If you're getting air, fuel, and spark; then it's a timing issue. If you're not getting one (or more!) of the three, correct that issue first.
 
5-90 said:
Remove the air tube from the throttle body, hold your hand about an inch over the top of it, and have a helper crank the engine for a moment - that checks for air.

Remove a spark plug, crank the engine, and see if you have a fine mist shooting out of the hole - that checks for fuel.

Take the spark plug, put it in the distributor end of the ignition coil lead, and hold the shell against the engine. Crank the engine and watch the plug gap. This checks for spark.

If you're getting air, fuel, and spark; then it's a timing issue. If you're not getting one (or more!) of the three, correct that issue first.

Damn that sounds so simple it should be in an FAQ!!!!!!!:greensmok Nice post 5-90!

If it is off by 180 degrees he could just set the rotor to 10 O'clock (by reseting the engine to tdc), pull and reinstall the distributor after turning it 180 degrees (minus a tooth or two for the rotation during installation) so that it ends up in the 4 O'clock position right? That way he does not need to mess with actually pulling spark plugs and finding TDC Exhaust versus TDC intake. Or just mark and pull the distributor, and reinstall it with the rotor pointing 180 degrees in the opposite direction.

By the way, I thought the final setting was closer to 5 O'clock on renix 4.0's, Is my memory faulty? As I recall you start at the 4 o'clock position and as the gear ingages and rotates it ends up at the 5 o'clock position. OK, I checked, I have an alldata DIY print out for Renix that confirms the final position to 5 o'clock and the initial position to be 4 o'clock.
 
Ecomike said:
Damn that sounds so simple it should be in an FAQ!!!!!!!:greensmok Nice post 5-90!

If it is off by 180 degrees he could just set the rotor to 10 O'clock (by reseting the engine to tdc), pull and reinstall the distributor after turning it 180 degrees (minus a tooth or two for the rotation during installation) so that it ends up in the 4 O'clock position right? That way he does not need to mess with actually pulling spark plugs and finding TDC Exhaust versus TDC intake. Or just mark and pull the distributor, and reinstall it with the rotor pointing 180 degrees in the opposite direction.

By the way, I thought the final setting was closer to 5 O'clock on renix 4.0's, Is my memory faulty? As I recall you start at the 4 o'clock position and as the gear ingages and rotates it ends up at the 5 o'clock position. OK, I checked, I have an alldata DIY print out for Renix that confirms the final position to 5 o'clock and the initial position to be 4 o'clock.

Don't know - I always make a fresh mark when I pull a dizzy anyhow. Comes from working on so damn many different engines once upon a time - I just set it to TDC, mark the dizzy where the rotor is, and make another small mark for where you should be setting the rotor to account for the helical drive gear.

Don't assume, and the manual isn't always right. Especially when you're dealing with automatic transmission valve bodies...
 
Thanks everyone for your help. I went throught the entire procedure again and i finally got the cherokee to start, but now it's back firing like crazy and the engine is smoking. What the heck am i doing wrong?
 
lazydragon said:
Thanks everyone for your help. I went throught the entire procedure again and i finally got the cherokee to start, but now it's back firing like crazy and the engine is smoking. What the heck am i doing wrong?
When the engine is at TDC, on the compression stroke, is the rotor pointing at the number 1 spark plug wire on the cap, which should be at the 5 o'clock position when facing the block on the passenger side?
 
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lazydragon said:
Looking at the picture, several things in the photo look a little bit different than our distrubutors (as I recall). A lot of the description is the same, but the 84 to 90 jeeps (Renix) the distributor looks a little different, and that photo looks like it shows the rotor pointing bewteen 5 and 6 o'clock, not at 5 o'clock, maybe its just the angle, I am not sure, Hmm???? Seems like the wires on mine come out more to the front than the side. I will take a look see tomorrow.

Maybe some one can post a photo of the renix distributor with it installed and set at TDC????
 
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