timing issue.
 

when i was adjusting my timing with the gun, i could see timing advance with increasing the rpm, but at higher rpm the timing would retart . i dont think that is normal for n/a, maybe that the reason the car has bad top end.

How retarded are you talking????? I rev my engine and while looking at my Palm connected to a RTEK2.0 the timing goes from -5 to about plus 14 at 1100 rpm then gradually climbs up to around 32 BTDC at six grand.

Inbetween the -5 and the 32BTDC I did see a drop of maybe five degrees at sometime. My figures are not exact, just what I saw when reving in the driveway a few times. If the boost sensor vacuum hose is off the boost sensor, you'll get a up/down reving at approx 3500 rpms til you rev higher, so leave the boost/pressure sensor vacuum line connected so you don't get this glitch.

boost sensor was connected, and line isnt cloged, maybe it needs to be replaced, your rx7 isnt n/a right?

Yeah, the Palm is connected to a turbo car. I've a n/a also.

So? Your still having this problem. How retarded is *retarded* when your talking about it retarding??? Take a guess.

hey hailers do you suggest advancing the timing a little for a s4 tII thats has a little mods, or maybe its retard it a little, confused which ever one makes more power, right now i have mine set dead on from the factory...????

its a weird problem, i think that only thing the could cause this is bads cas or broken wires.

Bum P

i wouldn't suggest advancing the timing at all on the stock setup for turbo applications, especially with the Rtek2.0, the timing already is too aggressive with the Rtek units and is a known problem.

for the OP, did you try reading for codes? the ECU may tell you what the problem is and why the timing is retarding itself, could be a faulty AFM or boost sensor or a variation of other sensors. TPS is one main one that comes to mind, if the TPS is not sending the correct signal the ECU gets confused and retards the timing, i find it alot with cars that have faulty TPS sensors where the car starts bucking very harshly.

*********Rtek2.0, the timing already is too aggressive with the Rtek units and is a known problem.********


You just said in the above, that the stock MAZDA RX-7 timing is too aggressive. Somehow that just does not and never will ring true.

I've two tutbo cars with RTEK2.0 and both boost/pressure sensors are good. Reving the engine in the driveway results in what I stated above.

So which of you'all have SEEN the Stock ECU timing in real time on a RX-7 while reving in the driveway? Or while driving?

Like the jpg below. The engine was rev'd to over six grand then let off (in the driveway). The rpms have returned close to normal idle but the Lead and Trail timing have not returned back to the normal -5 and -20. Given two to three seconds and they will do so.

About the usage of BOOST verses PRESSURE on Turbo or non turbo engines: someday take a look at a NON TURBO FUEL SECTION of the series four FSM. Looking closely you'll see a picture of the Boost sensor and remarks about the usage of the BOOST sensor on the non turbo engine. Jpg attached.

Called RX-7 trivia topic.

Anyway, about the timing in the driveway. I went out to a fully hot engine and SLOWLY rev'd it to six grand. I took over thirty seconds to do it. That means SLOWLY.

When the tps was in the range of the low ninty range, the lead timing was approx 35 BTDC. The moment the tps was at full range and over, the timing stayed at 32 BTDC all the time. So, I'm saying the timing dropped/retarded a touch. A lot depends on how fast the engine got rev'd, how quickly the tps was lifted to full open range. Stuff.

The afm determines timing also, so you have to consider it's effect also, as you rev the engine.

hailers, you are running carb and cas, you added tps for timing advance. i plan to run carb also, but was wondering if i could just set the cas to 32 btdc to run at all the time, without any advance, without tps. Dead timing.
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