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-   -   TEST drive:gets up to 3.5 k,and BOGS! (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/test-drive-gets-up-3-5-k-bogs-861552/)

misterstyx69 09-05-09 07:19 PM

TEST drive:gets up to 3.5 k,and BOGS!
 
Car is an 86 N/A converted to a TII,using the N/A harness and all s4 TII components..all part on the engine are Stock...got an FMIC on though.
After 4 months Of tracing a Problem,I Finally got the car to run in the garage and Not Die If I step on the gas..WOOT!
So,I took it out for a Test drive..Sounds good.below 3.5K..But If I HIT the gas..NOPE!..it will BOG down.,I let off the gas,and it will Run OK..
can anyone help?..or Give me some Ideas I can Go on,to help me get the car to Run above 3.5K and Give me the power of BOOST!!!!!)
Thanks Guys .DAVE/STYX!~

calpatriot 09-05-09 07:36 PM

A lot of things change in that 3500-4000 rpm range under heavy throttle. The aux port solenoid commands the removal of air pressure from the closing side of the aux port actuators, and if the back pressure is high enough they start to open; the secondary injectors come in and the duty cycle of the primaries are cut back to compensate; the EGR valve closes (no more exhaust gas into the intake above that rpm); the split and port air stop and the pump air is routed into the bottom of the intake pipe between the air flow sensor and the throttle body.

1. Warm it up
2. Check for ECU trouble codes
3. Check for closed loop operation
4. Use the green lamp check or a voltmeter and see if the mixture is going lean at the point the power loss occurs
5. Adjust idle speed (FSM)
6. Adjust idle mixture (FSM)
7. Check and adjust TPS with a ohmmeter; look for dropouts; adjust to exactly 1k ohms at idle throttle
8. Check timing
9. Check operation of spark advance
10. Check operation of EGR (per FSM)
11. Check operation of port air/split air per FSM
12. Check operation of boost sensor per FSM
13. Check operation of air pressure sensor per FSM
14. Check the air flow sensor per the FSM

If none of that works, I would pull up the carpets and plate on the right side, and backprobe the connections on the ECU and compare the voltages on the 52 pins there with those listed in the FSM.

misterstyx69 09-05-09 08:33 PM

OK..I forgot to mention something.(well a couple of things!)
The engine is a TII with block of plates/emissions removed.
it is a Bare setup.just enough to run the engine.
all 550's are LO..running an #333 ecu with resistor pack on the harness.
it has an S4 Lower with an FD upper and is running the FD TPS.
..I don't understand why I would look for aux port activation on a TII.chuckle..(they are only on an N/A).Unless you intertpreted the engine as an N/A converted into a TII engine.
Car has NO EGR..it is an S5 TII Keg Streetported.No boost solenoids to bother with either.
...it Revs up Fine when it is not Under load.but once I put it in gear and get about 3.5K it will Bog...
I am gonna Change TPS.check Timing marks,and CAS position(again).
anyone else have more Ideas?..(thanks for Posting up Calpatriot.)

1SWEET7 09-05-09 10:37 PM

Can you get above 3.5K with partial throttle?

MazdaMike02 09-05-09 10:44 PM

I would probe the injector wires. I heard from a friend of mine that he had a short in one of his injector wires causing a short at 3500 rpm.

sar 09-06-09 12:15 AM

3800rpm is when the secondary injectors are kicking on. It sounds like they are not getting power. Check ECU/Body grounds, secondary injector connections.

misterstyx69 09-06-09 10:21 AM


Originally Posted by 87 t-66 (Post 9476836)
it sounds like the flux capacitor...that's gotta be it dave!

The whole car is "FLUXXED" Adam!..been FLUXXIN with Me for 4 months!
Ya,I gotta see what the Injectors are doing.,it seems like NO fuel/Fuel cut,something like that.
anywas,keep the ideas coming.Thanks,Dave.

calpatriot 09-08-09 03:06 PM

Do you still have an O2 sensor? if for example the secondary injectors are not coming on, that would be driving the mixture lean, and that would show up as a low voltage (<o.45) from the sensor.

barnett87rx7 09-16-09 02:42 PM

dave did you check the main ground I had the same problem cleaned the connection and it was all good. aaroncake has a good website on it.

misterstyx69 09-16-09 09:23 PM

Grounds are good,I ran alot of extras,just to be sure.
Now,I Tried a different ECU,and that was BETTER..(I was able to get BOOST!..finally.).. now I am not hitting a "wall"..
BUT I now have Irritable Idle,and a slight Transition Problem..(sound like the TPS????),and it IS an FD TPS(FD Upper conversion on an FC TII engine)..so that is a real Beotch..
I am going to be changing TPS and the Boost Sensor on the car..this week..stay tuned for "FLUXXED IN SPACE".part 362..(hey,there is a Jedi in my Tank!)


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