im working on my s4 gxl to get it going again, a while after i did the engine swap in january, one day on my way home my tach stopped working, the rtek still showed me rpm though. when ever i reved it past 5k it would start backfireing almolst like a rev limiter. i got home and shut it down, after wich the starter wouldent work, so we push started it. tach worked to a second then gave out now it would back fire at any time i even touched the throttle. later we push started it again this time still no tach but no back fireing at all.

i want to try puting a different set of secondarys on it to see if it fixes the problem. so if any one has some kicking aroud could i borow them? if i break em ill buy them. if they work ill buy them if your willing to sell.

 

You mean Trailing coil? The car will run without trailing plugs firing at all.

You've got other problems, wiring/vacuum leaks?

 

If you want to try some new used coils that work, pm me. I have a bunch in my garage that you can try.

But I agree with Joe, it doesn't sound like a coil problem to me. More like a setting in the R-Tek or a vacuum leak. Another thing may be the fuel pump or fuel pump drivers or fuel pump wiring. Heck I have spent the last 5 years tracking down weird misfires in an S4 based system and should be able to help.

Eric

 

^^ my car has misfires while idling never idles smooth, sometimes it bounces sometimes it idles high but always studders every so often lol,

Im thinking its grounding issues

Mr.cool are your trailing wires switched?

 

as far as i know there right, the car ran and drove fine(though slightly under powered, it seems) for 2 and a half months. then one night, as if someone flicked a switch this happed.

 

im guessing putting low independance injectors in an 88 that normaly uses high is bad? im so stupid for not looking into this befor, as some may know the engine i swaped into the gxl was theorys old engine from his 87. i used his injectors not knowing that 87's used low independance injectors and 88's used high ones.

this might also might be the reason why the car would idle at 3000 rpm and not come down (though the car likes to fix its self, that just went away after a week of scratching my head) could it also cause the problems i listed above? im still going to go through the wireing and vacume lines as im 100% sure there wrong. the engine is an s4 with s5 intake so i was compleatly lost when it came to the vacume lines. and the wireing is well, not bad but its not 100% right.

do any of you think you might be able to pop by one day and take a look. if you could fix even one line ill be that much closer.

thanks!