10thanniversaryrx7

ok guys i got everything figured out with my cold start problem. but now i have another problem. she rund great normal driveing but when i get into boosting she pops and has no power and i have to let off her. I have noticed the timing is way advance on her. can anyone help me outwith this.

SureShot

You are very near or already have caused engine damage.
Causes: too musc spark timing advance, too lean fuel mixture.

Do not ever allow a rotary engine to ping, pop, or detonate.
The apex seals will fail.

A quick check - Listen to the exhaust at idle.
It should purr at 800 RPM.
Any rythmic miss? - it's hurt.

A compression test will verify it's health.

10thanniversaryrx7

she purrs like a kitten at idle. I don't believ i have caused any damge to her cuz i let off assoon as she popped. can you give me any idea on how to fix this popping problem so I don't fry a engine. thanks in advance.

Turbonut

iTrader: (1)

First I would set the timing to factory specs. If it still pops under boost, possible stuck/cracked seal.

jacobcartmill

iTrader: (6)

bah popping could be a number of things, especially under boost. why does everyone on this damn forum automatically point the finger to a blown engine?

replace the spark plugs/wires/o2 sensor, check your timing, etc.
your spark plugs could be fouled out (or getting there, which is my bet). i am fouling out spark plugs, and when they're going out, it hesitates/pops under boost. dont automatically point the finger to a blown engine until you've checked out everything else (of course after knowing you have good compression)

hondahater

iTrader: (2)

is it at 3800rpm??? Mine does the exact same thing right now under boost but it's around 3800rpm hense the infamous 3800rpm hesitation.

jacobcartmill

iTrader: (6)

if its at 3800rpms thats a different problem. my first turboII (87) did that and i redid a couple grounds and replaced the resistor pack up by the headlight plugs and it went away. then it came back a week later

anyways, let us know if its the 3800rpm hesitation, if not then check the stuff i mentioned. if it IS, do a search and you'll find like 1233451231235235 threads on it

SureShot

That's good.

On to plan B - check out jacobcartmill's suggestions.

hondahater

iTrader: (2)

hye jacob what resister pack are you talking about??? Are you talking about for the fuel pump??? Thanks! I'm trying everything including

1. regrounded everything
2. new ignition (msd) coils and msd6a
3. new fuel filter
4. new fuel pump strainer
5. redid the connections for fuel pump rewire and msd6a

still haven't found the cause so if this resistor pack is something differant let me know! Thanks

10thanniversaryrx7

I have put new plugs in her yesterday. It only does it if I get into her hard and booster I'm going to try and mess with the timing when I get home and some other things. I don't believe it is the engine has no miss or anything at idle or normal driveing.

Rx7MPGUY84

how about this. when u first start it does it do it. when hitting boost. cuz mine does the same popping **** after its warm, like driving for 20 mins. and only when i go wot. if its doing that, just shut the car off while driving and start it again, popping the clutch or using the starter, it doesnt matter. if it works again. its the same problem i have. if anyone knows how to fix it post it. im lost. thanx and good luck

Rx7MPGUY84

mines not really popping i guess. its more of a sputtering. so i think mines still okay. idk. help me people.

Turbonut

iTrader: (1)

Because it's a possibility. A compression test wouldn't necessarily indicate a cracked/stuck seal. Could stll show good numbers, but kick back under boost.
Oh, and by the way, you have a thread asking for help on fouled plugs!!!Interesting.

OverDriven

Doubt its a blown engine. You may be hitting fuel cut. It will loose power up high and hesitate.

-Joe

10thanniversaryrx7

I'm waiting for my fuel cut defender to arrive. I believe that the wastgate was ported and some other work done to her but not to sure what. They guy that had it befor the guy I got it from said he had it running 9 in the 8th and there is no fuel cut on her so is this what you guys think it it is.

Thanks

jacobcartmill

iTrader: (6)

i bet its the spark plugs and/or the TPS

my car hesitates under part throttle and under boost at part throttle. im gonna go adjust my TPS today, i just wire brushed my spark plugs

87RX7TII

is the popping comming from the engine or the exhaust?

10thanniversaryrx7

from the exhaust but i believe i have that fixed. The timing was way out still has a lil miss under boost but I believe that is a plug wire breaking up and load. What do u guys think.

87RX7TII

I need to adjust my timing too, its long overdue.
So your saying after you've re-adjusted your timing the boost "popping" went away by about 90%?

If you still have the 17 year old wires like I do thats whats prob giving you your problem. why not replace them all and see how much better it works. (even if its not the problem the car should run stronger with new plugs and wires....

10thanniversaryrx7

yes when I adjusted the timing the boost poping went away. just as a miss under boost and is going lean. Just hooked up my a/f gauge yesterday and on the way to work got into her and it went lean so now i have to fix that problem. I changed the plugs going to chaange the wires today when my check gets here. see if the miss goes away. I was alsothinking could it be fuel cut that is maken it miss under boost.

Turbonut

iTrader: (1)

Without reading all the thread, after the plugs, wires(correct location), as mentioned check tps setting and operation. Check the BAC valve for any internal leak. The inner seal has a tendency to leak and allow unwanted air to enter the intake (lean condition). Check fuel pump voltage under full throttle to be certain the voltage jumps over 12. You can also check fuel pressure and hold pressure. You can also check pin voltage at ecu to be sure all input according to fsm.

10thanniversaryrx7

I'm kind of rotary dumb here so don't know much aboout them. I checked and set the tps at 1 ohm. but under wide open thorttle it jumps to almost 7 ohms does this mean that the tps is bad. where is the bac located on a rotary so i can check that anyway to check for a internal leak.

Thanks for everyones help.

DerangedHermit

To be safe, if I ever hear pinging, popping, backfiring etc, I'm backing off, limping home, then getting it checked out.

DerangedHermit

Hey, as long as you're willing to put in the work and learn about the engine, it's all good. I don't know much about them either, but I try to learn as much as possible by reading the forum and other sites (Reted's especially). Also, I've got a Hayne's and read through it several times, very useful book.

gildardo

Yhea 10thanniversaryrx7 your TPS seems to be bad. I don't think it's suppose to go up to 7ohms. according to the workshop manual it's 4 to 6 ohms at full throttleon the narrow range ant 3.4 to 5.1 on the Full range.