ok hello ...i was working on my 88 duke today swapping plugs..no biggie.right?then while removing one plug it broke.got thru that then while pulling a plug wire, i left the little terminal thingy..thats supposed to be insidethe boot..well its still on the spark plug..ok mnow i went to the "i really dont know anything bout your duke sir" parts store..but this time i got some accel yellow wires {for a 350 chevy}well i got it all back together and all was well for a little bit i let it idle till the fan turned on then i went to the street.stood on it and it pulled nice all the way to 3000 then bang..backfire throo the t/b...it seems to have a miss while free revving and really goes bang with a load on it....so did i just mix up the firing order or what ?...

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fun is rowin throo my 5-speed

Petition the Ogre. Or at least read his articles.

i already went throo the caves and did not find the info i wanted like,how are the cyl numbered and what side of the motor does the count start from ?is no.1 on the trans side or the acc. side? thanx though

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fun is rowin throo my 5-speed

Cyls are numbered 1-2-3-4 starting from the A/C side going toward the trans

Yes, the cylinders are numbered starting at the pulley side as 1 and the tranny side is 4. Firing order is 1-3-4-2, although this engine is probably a DIS with coil packs rather than a distributor. Sometimes, the cylinder number is labeled on the coil pack.

If the plug wires appear to be routed correctly, then check to make sure you're getting good connections with the plug wires. Especially since these wires are not really for that engine.

Check for fit at the coil pack and at the plug. Maybe they don't fit tight enough? Maybe one is not pushed on all the way?

Hopefully you gapped the spark plugs properly. You can't just take them out of the box and slap 'em in. You need to gap them with a plug gauge.

The coil packs are 1/4 and 3/2 if that helps any.

Phil

I had a problem when I changed my plugs too. I have a GT though so I cannot personally help. Here is the thread I started this should help alsoif you have a hayes book look in it. https://www.fiero.nl/forum/Forum2/HTML/024228.html

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If it runs to 3000.... the firing order is ok.

Actual Firing and Cyl layout is not relevant on this motor. 1&4 go to the bottom coil, 2&3 go to the top. It doesn't matter what end you count from or which way each pair goes on the coil. It only matter that the correct pair is on the correct coil.

The first things to check over is vacuum leaks, EGR, and PCV. Make sure the vac lines are all routed right.

It's ok thru higher RPM... Assuming your bodged wires and plugs aren't a problem, you could have a bad coil or crank sensor. You did gap the plugs to .060??????

Allot of people have had trouble with Bosch Platinum plugs, so if you used those you might want to pull them out and use regular Autolite or AC.

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11-Sept-01, The day the world as we knew it ended.

ok well i have great news.......i fixed it.
it all came down to a crossfire condition between the plug wires down by the coils...a couple of wire seperators and not a problem no mo...i feel alittle dumb.
oh ya i only use delco plugsand the gap is correct at .060.... my bosch wires NEVER did this.but these damn accel 8mm yellow wires really do need to be seperated.thanx for the help and info gentelman
big rob...( impressoins felt )