I just got done replacing all the plugs, wires, dist. cap and rotor and now the engine won't fire. All I get is some popping and an occasional loud bang. I check plug 1 for spark and didn't get anything. Would there be no spark if the rotor is 180 deg off? It's my '85 TPI Z28. Thanks

Is the firing order back on right? how about the rotor?is it seated right? is the button in the center of the cap making contact with the rotor? is the coil plugged in? how bout your spark plugs, did ja gap them right?

Double checked the firing order a few times, rotor is seated right, the button is making good contact with the rotor, coil is plugged in, gapped spark plugs at .035. The only thing I'm not sure about is if the rotor is in the right position. The car was running when I took everything apart.

Try and disconnect the battery maybe the computer has a glitch. That happened to me one time. i disconnected the battery for a bout 20m minutes after that it fired right back up. just a suggestion

Ok, unhooked battery and rechecked the firing order. Took coil off and checked the wires, put coil back on and checked firing order again. Hooked battery back up and gave it a try. Still nothing. Checked for spark on all eight cylinders and all are getting good spark. So, checked fuel pressure, 38 psi. Still no fire, just a slight hesitation and occasional backfire. Does anyone have a firing order diagram for TPI? I thought it was the same as any other small block chevy. Any other idea's?

here's the firing order,

Should be the same as every other SBC. Sounds like your firing order is off or rotated. Pull #1 plug, rotate your engine til its on TDC COMPRESSION stroke. and then take the dist. cap off and make sure the rotor is pointing to the wire that goes to #1 spark plug. Rotor should only go on one way...But your condition sounds like when the distributor is 180 off...

he probably put the wires onto the distributor counter clockwise as apposed to clockwise OR got the wrong point on the distributor as number 1 and consequently set the whole thing off

i agree that's what it sounds like to me too

that would definitely do it.

When you replaced the wires, did you change them one at a time? Or did you pull them all off and then replace?

If you did them one at a time, and did not remove the distributor, that leads me to the rotor.

You can't install the rotor improperly and still get the cap on right, so at this point, I would take the rotor out, and check it for a carbon burn. Occasionally, a defect in the rotor allows the spark to burn through to ground, and this will result in symptoms like yours. If this has happened, you will see a black burn spot near the center of the rotor.

ey did you ever solved the problem im having the same exact problem replaced the plugs and cap and rotor and now it will just crank but no start and pops

sounds like your wires are not in the right order

Get a socket for the balancer bolt. Breaker bar, rotate the engine by hand till timing mark is @ 0.

Now put a piece of tape on the dist cap, across the distributor base, right near where #1 wire is in the cap. Cut the tape cleanly, and pull the distributor cap. The rotor should be just AFTER the tape, OR, exactly 180 degrees away in the other direction.

If not:
Get spec timing advance. Rotate crankshaft to that degree. Loosen distributor holddown fork, and rotate distributor to get the rotor directly on the tape. Tighten the distributor.

IF SO:

Set the cap back down, and follow the next wire to #8, 4, 3, 6, 5, 7, 2 cylinders respectively.

This is called static timing test.

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Wrench Wizard OUT!!!

igot the car running again now the problem its having shuts off wile putting it in drive the car is great in neutral but once set in drive or reverse shuts off.i have also noticed when removing the MAP sensor vacumm the car happens to run but times still shuts off what can it be.icheked egr it seems fine

Read
https://www.thirdgen.org/forums/tech...formation.html

If we had some idea of what car you owned, it would go a long way to you getting accurate help

sorry about that its a 90 camaro 305 tpi manual transmission

Just a heads up for future people who change the cap and rotor and find their car won't start after. The diagrams that show 1,8,4,3 etc are correct. But the diagram is a bit skewed compared to what the cap terminals are.

Say you're standing at the front of the engine. The #1 and #8 on the cap would seem to be 5 o'clock and 7 o'clock respectively on the cap. I spent an eternity tracing wires (not easy with black wires on stock manifolds) and everything was lined up in the correct order.

Turns out that everything was off by one. The #1 on the cap is really more like 4 o'clock when you're standing at the front of the engine. I only noticed this because the old cap I'd taken off had a purple line drawn where #1 goes. Moving all the wires one spot over and voila.

Would be a better choice to replace the plugs and wires one at a time, then this wont happen!

I couldn't get the cap off without removing the wires. There is zero extra slack on my spark plugs wires.

So the red mark on this was yer #1 ?