Well, he we go again. Another topic concerning detonation. I'm stumped. '89 TII I purchased new, completely stock. Car starts great, idles great, cold & hot, pulls strong, no hesitation, but occasionally you'll hear the engine kick back, and that wounderful detonation sound when under 3/4 or full throttle in 3rd, 4th, or 5th gear. Boost is fine, gauge in middle, automter reads @ 6 lbs, timing right on, new plugs, no visible vacuum leaks. Going to check EGR system this weekend to see if system is operating properly. It's not the cats....Checked by putting on a Bonez downpipe and new Bonez hi flow cat with fcd, same problem, only this time sound a lot louder. This occurs sporadically even with 93 octane.
Any ideas, suggestions would be greatly appreciated.

Don

 

Check to see the spark plug wires are in the correct spots!



-Ted

 

Thanks Ted-Plug wires new, and correctly placed.
Timing on L1 & T1 right on both marks @ idle.

 

i would say you have a fuel problem or ignition problem. my TII with dp and mp and ecu hits 11psi with no hesitation. if you need a good shop to check it i know of one in north NJ. maybe you have a bad leading coil ? turborotor's car did that just last weekend we replaced the leading coil and bam car is hitting 14psi !!!! if you can get spare coils they are very simple to change out
as an afterthought that sounds like an ignition problem to me......not enough spark for all that fuel causing it to break up!

 

I'll give it a try. I have extra coils, ecu's etc. Will try replacing coils this weekend. Thanks for the info.
By the way, which shop are you speaking of in North Jersey?

 

Sounds like a fuel problem. Check for at least 12 volts at the fuel pump under WOT. If it stays around 8-9 volts, you have a bad fuel pump resistor relay and/or ECU. If it does stay at 12V, replace the fuel filter if it has not been replaced recently - it might be clogged. If this still does not help, I would check fuel pressure under WOT - it should hold at 38-40 with no boost, and start gradually moving up as you go under boost. 50 is the max, but I do not believe you will get to much more than 45 on a stock engine, if even that. Just an increase in pressure under boost would indicate that it is working.

Irv, Keith's dad

 

jr's rotary performance in paterson, nj. the only shop all three of my rx7's goto. where are you located in nj. i'm in parsippany. you should checkout the NE forum for the bbq june it should be alot of fun where did you get extra coils,ecu's etc

 

Thanks for taking time to submit the replys.

Irv-Filter just replaced, but will check pressure/voltage this week.

Vosko-I live about 6 miles south of Flemington. The parts came from an AE I stripped down. It had no engine/trans, but I removed most everything else just in case I needed it. The ecu 370 I purchased.

 

cool good deal. any parts i need jr's usually has lying around so its not a big deal. its always a good idea to have spare parts. if you want to come to parsippany nj you can try my panspeed ecu and see if the car does the same thing..... that will tell you if its a fuel issue or just come to englishtown tomorrow

 

Vosko:

Thanks for the great offer...I'll keep it in mind. You're only @ 1 hr away. Will "tinker" with it this week and do some changes/ tests. Not a daily driver, actually just sits in garage until nice weather. Used it this weekend and today in 3rd @ 35 mph under load it kicked back once, with that wicked sound!

Thanks again,
Don

 

i am very impressed with the panspeed ecu so far the car runs flawless no hiccups ANYTHING... just lemme know if you want to try it or even see if i notice anything wrong on your car