fsae_alum

Car Background: COMPLETELY stock with the exception of a downpipe and a K&N filter. Replaced fuel filter, wires, and plugs 2 months ago (2K miles).

Well, I dove into doing the Vac hose job on my FD since I was already in there to replace the FPD and get the injectors cleaned. When I took it all apart , I very carefully numbered every line connection with tape and a marker and followed that up by subsquently numbering the infamous colored vacuum hose diagram. I also labeled each electrical connection that I unplugged with tape and alpha characters. Put it all back together very carefully following the numbering /lettering sequence and the vacuum diagram. I started the car and let it warm up. Purred like a kitten, nice and smooth. Then adjusted the TPS to be spot on. Took the car out for a drive and anything above 1/4 throttle, it would fall flat on it's face. It's not dying but it just feels like somebody threw out an achor while I'm cruising along. Came back and checked codes and had one for the wide range TPS and one for the narrow range TPS. Cleared the codes and then double checked that they cleared. Took it out for a spin and same damn thing is happening. Came back and checked codes and it was all clear. Erased the ECU memory again and double checked it yet again to make dure it was clear and took it out for another spin only to have the same effect. Here is what I've checked so far without taking off the UIM:
1.) Double checked all of the visible vacuum lines and they all appear to be ok.
2.) Double checked the direction of the 4 check valves (3 plastic and one metal) that I could see without taking off the UIM and they appear to be good.
3.) I took off the Pressure Chamber and looked for any kinked vacuum lines under the UIM and didn't see any.
4.) Double checked that all the lines are plugged into the UIM and they're all there.
5.) Double checked the MAP sensor vacuum lines.
6.) Verified that the Double Throttle Actuator was fully extended while hot
7.) Visually verified that the vacuum lines doing to the Double Throttle solenoid are hooked up and in the correct location. Also verified that they;re plugged into the UIM and the Double Throttle Actuator on the backside of the UIM.
8.) Verified that the FPR vacuum line is attached to the FPR and doesn't APPEAR to be kinked.

Beyond that, I took it out for a couple of more test drives to further understand the problem. I can be in 1st, 2nd, or 3rd and the problem is still there. I can very gently feather the throttle and creep up the RPM's to about 4000 RPM max before it cuts out. I can also just try to get on it and anything above about 1/4 throttle and it just slams the engine power down. Don't have a boost gauge so I can't tell you what the boost is doing but from having driven it before when it was boosting fine....it currently feels like I'm getting very little to no boost at all.

Anybody have any ideas before I tear back into this?

One other question I did have is if the double throttle is fully extended and and I push it in, I can hear the double throttle solenoid releasing air....is this suppossed to happen?

Any help would be appreciated!!

Thanks!

cabaynes

iTrader: (4)

Not to sound rude but you went about the vaccum hose job the complete WRONG way. When you go to replace all your hoses, you should do them one at a time. Leave all the old hoses in and one by one replace them with new ones. That way you dont have to be numbering hoses and looking at the vaccum diagram trying to figure out where they go. If your idle is normal then it's not the MAP sensor, but if it's got problems building boost then you probably either crossed up some lines or reversed a check valve.

fsae_alum

Ummmm doing them one at a time in the area around the solenoid rack prevents you from accessing the lines that are under and behind the solenoid rack. You have to remove the rack to access those. Likewise, not removing the solenoid rack makes it quite difficult to remove the fuel rails and injectors.

I removed one hose at a time and everywhere I disconnected a hose, I labeled it with a piece of numbered tape on both the hose and the pertaining connections. I then removed the solenoids one at a time and labeled each of those as they came out. For the lines that were not around the solenoid rack, I replaced them one by one (with the exception of the ones on the passenger side of the UIM that lead into the turbo's - had to do those all at once...again with labels).

Question is...does this sound like it's a FPR or Double Throttle or ACV, etc... issue?

Thanks again!

DamonB

Sounds like limp mode to me.

You have an electronic or ecu problem. No vacuum line could cause the problem you have.

DaleClark

iTrader: (55)

I think you may have your TPS's adjustment off, or you swapped secondary injector plugs around or something. Start with the TPS - if the ECU got a code for it, you're going out of range on the TPS.

Also, if you adjusted the TPS without the fast idle cam kicked down, the settings will be totally off.

Dale

fsae_alum

Damon......thanks man....that's what I was wondering about. Nice to know that it doesn't seem vacuum hose related.

Dale....I rechecked the TPS voltages about 4 seperate times with the car warmed up on every occasion and the voltages are within spec. That was also done following Damians method of making sure that the idle control is closed all the way off and the idle adjust screw (verticle one) on the top of the throttle body is fully backed off.

Regarding the Fast Idle Cam....Dale, you got me on the ONE other thing that isn't factory about the car. I have the throttle body plumbing disabled (as it doesn't really freeze here in San Diego) and likewise have the FIC disabled by having the screw in all the way. Had this done months before I dove into the vacuum job.

All the research I've done tells me it's the TPS throwing the ECU into limp mode. I KNEW I shouldn't have messed with it. Only change one thing at a time is the golden rule and I clearly violated it. Oh well....time to fix it. I'm thinking that I'm going to start the car and then unplug the TPS and plug it back in to see if that trips the computer into throwing a code related to the TPS. If it does, then I should know that the computer is ok and picking up the fact that the TPS is out of wack. If I don't get any error codes, then I know that I've got an issue with either the TPS or the ECU.

Any other ideas? Is there ANY, and I mean ANY way that a crossed or kinked vacuum line could cause this? Just double checking here.

scotty305

iTrader: (2)

From that description, I'm going to guess that your TPS could be indicating that it's at wide-open throttle when you're actually closer to 1/4 throttle. That would dump lots of fuel, and you'd notice a smooth decrease in power. I know this is a bit counter-intuitive, but you might try giving the car full throttle to confirm this. As you know, this would be a very dangerous thing to do if you don't have any other indications that the car is running very rich. Are you noticing a strong fuel smell? The other thing you could do is turn the ignition on but leave the engine off, and measure the TPS voltage at various throttle positions, to verify that it's not sensing full throttle (4.8-5.0V at ECU terminal 3F, and 4.2-4.6V at ECU terminal 3G) until you're actually at full throttle. (see pg F-168 of Workshop manual)


Another thing I just thought of, are you sure you adjusted the correct terminals to the correct voltages? I'm not sure if it's possible to adjust the TPS to reverse the settings, but I'm sure it would screw things up pretty badly if you somehow did.

-s-

fsae_alum

That's the thing....it's not running rich and it's not a smoth decrease in power either. It's like you're driving along and somebody has tied a chain around the axle and all the sudden it gets taught. It is a very sudden and dramatic drop in power. Imagine throwing a stick in the middle of bicycle spokes and the dramatic decrease in momentum you'd get.

I've been through the whole process countless times of warming up the car and then turning the key to the "ON" position but not starting the car and checking voltages at both opened and closed (as well as the range in between). I even thought like you did that "Maybe I pinned the wrong connections on the TPS sensor connection" but I double checked that and it came out fine as well. Question is...if I did indeed pin the wrong wire (third one down) and if the other multimeter lead is grounded like it's suppossed to be per the instructions, could that short out the TPS or the ECU?

Also starting to wonder if maybe I maybe by some mistake accidentally fully started the car with the diagnostics box pins ten and ground connecetd and it caused a short in the ECU as well that would be causing the problem?


Aye....

Kento

You need to make a very close examination of your TPS and its components. See if you can get another known good TPS and swap. The description of events in this thread all point to the TPS as the root cause of your problem.

CantGoStraight

Did you have the TPS off the TB ?? Reason I ask is that you may have in stalled it incorrectly (don't have it meshing with the tabed piece dorrectly, TB butterflies may be moving but the TPS isn't.

fsae_alum

Sure did have it off.

There are two sets of U channels on the inside of the TPS housing. Are the tabs on the TB suppossed to go inside the stops at the end of the U channels or are they suppossed to line up with the other side of the stops? Basically, do the tabs go inside the channel or outside the channel? I tried to install it both ways but when I did it to the inside, it preloaded the hell out of the TPS sensor. The holes wouldn't line up without preloading the TPS sensor by about 30-45 degrees. Had to take the sensor off to change out the stupid screws with Socket Head Cap Screws. I also took it off in an effort to see if was a case of adjustment was achieved by merely rotation or by a combination or rotation AND displacement back and forth.

CantGoStraight

Don't know about the channel on the TPS and which way they contact the tabs on the TB but if you put the TPS with the ears your talking about between the TB tabs and rotate the TPS CCW(counter clock wise) till they come together, you'll feel the TPS contact the tabs of the TB and a slight spring tension as you continue to rotate it CCW till the TPS slots line up with the threads on the TB. I believe the TPS connector pointing at 11 oclock looking at the TPS housing from the end with the TB Top at 12 oclock should drop the TPS tabs between the TB tabs any way the TPS top tab should be to the right of the TB top tab and the TPS bottom tab should be to the left of the TB bottom tab before you rotate the TPS CCQ on the TPS housing. Hope this is clear enough for you to understand as I feel like I may be making it more complicated than it really is. Jack

fsae_alum

I ACTUALLY understood that perfectly. It's all starting to make sense now....hopefully. I'll check it tonight when I get home and update everybody on what I find out.

Thanks for the help Jack Dale, Damon, and everybody else! It is MUCH appreciated!

fsae_alum

Well....back to the head scratching for everybody here.

Listed below was what I did tonight and the results:
1.) Removed throttle body with TPS intact and carefully removed TPS to check installation. Verified after operating the throttle by hand that the tabs were indeed in the right place and moving with the TB barrell as it turned. Thinking back, it would have to have been installed correctly to get the voltages to line up correctly at Fully Closed and at WOT.

2.) Put it all back on the car and checked for codes left over from last night...no codes declared by the ECU. Started the car to let it warm up and then noticed that I had left the damn jumper in place betwee TEN and GND in the diagnostics connector. Removed the jumper and the engine RPM's knocked down by about 50 RPM. That means when running the ECU is referencing those pins. Hmmm...

3.) After letting it warm up for about 10 minutes so that the temp needle was in the middle of the gauge, I turned off the engine and then turned it to the "ON" position and fully closed the Idle Adjustment Screw under the TB. I then verified that the TPS voltages were correct closed and WOT per the FSM. Somehow I was damn close just by putting it back together in the middle of the adjustment slots.

4.) Checked for codes again of which none were produced. Started it up, bumped up the idle under the TB just a tad. Purrs like a kitten.

5.) Took it out for a spin and it does the same damn thing. Argh!

6.) Bring it back and check for codes...nothing!

7.) Remove the TB and swap out the TPS for one that I have been told is a good reference TPS. Adjust the postion so that the voltages are almost 100% spot on with the median values for Fully closed and WOT. While I was there, I verified that the harness and spark plug wire connections to the coils is all good, to which they were.

8.) Start it up and take it out for a spin only to get the same damn thing. This time I tried to see what would happen under no load. I got a good speed going, put it in neutral and coasted and then revved it to see what it would do. As soon as it got to 4K it hit a revlimiter. Verified that 2 mores times. So, even with no load, I still can't get it to rev past 4K. Hmmmm. Again...no codes.

I'm starting to wonder if the FPR line is indeed kinked or somehow disconnected. Same thing could apply to one of lines for the turbo that matter. I'm really leaning towards an air delivery issue though and suspecting the Double Throttle system. Then again, it could also be that the secondary injectors are not coming on line.

Anybody else got any more ideas?

Oh yeah...forgot to add that I have an inline fuel pressure gauge and the pressure is within spec at idle. I have also not yet checked to see if disconnecting the TPS with the car running and then reconnecting it will throw a code (to see if there's some reason that codes aren't being captured or flashed). I'll leave that for tomorrow night.

dgeesaman

iTrader: (7)

Gosh, these symptoms remind me of my injector problems. I had mine cleaned but not flow-tested during a hose job (I assumed cleaning was cleaning - bad idea), and when I put them back in they caused the same thing - anything above a little throttle resulted in cutting out and later, when it would allow me a little more throttle, bucking.

Dave

CantGoStraight

^^^^ Thinking the same thing.

DamonB

None of those could possibly cause the severity of the problem that you have. You either have an electronic problem or perhaps an injector issue since those were removed. As Kento said the ecu is pointing you to the TPS so there is some issue there. I'd swap the TPS with another known good one before I ruled it out, even though your measurements don't show a problem.

This is exactly what it feels like if the car is in limp mode. The engine runs fine until you put enough load on it and then instantly falls flat on its face.

I would swap the TPS. If that didn't change anything I would troubleshoot the injectors and fuel pressure. Don't go off on other tangents until you've ruled those out.

fsae_alum

Damon, I'm no longer getting codes but I am still getting the same problem. I DID swap the TPS out for a known good one and again.....same problem with no codes.

DGeesman and CantGoStraight....that's interesting that you suggest that. Max Cooper said that at one point in time he had the EXACT same problems and symptoms as I'm having (including the no codes) and it turned out that he had an injector that was stuck as a result of getting them cleaned at RC. Looking at the FSM and seeing that the secondaries only come on above 2750, I was seeing that it could be that something could wrong with my secondaries. I figure that my new course of action will be to remove the UIM and verify that harness connections aren't somehow swithced. If they aren't then I'll jump FP and GND to have the pump pressurize the rail. I'll then remove the jumper and unplug the injectors one by one and briefly click them open with battery voltage to make sure that they're working. If in testing one of them doesn't result in a drop in rail pressure, I'll have determined that it's an injector problem for sure. Why not just take the rail off you ask....wouldn't it be easier to unflood the engine as opposed to digging back into vacuum lines around the rats nest? Unfortunately I won't be able to get to work on this until tomorrow night.

Thanks everybody for tuning in and helping out!!! It's very much appreciated!

DamonB

^ Now that you have no codes your issue does support the secondary injectors not working properly as they only come online once a certain engine load is reached. I think your plan to check them sounds like a good one. If your plan doesn't turn anything up I'd try a different set of secondary injectors.

I'd test the injectors with no fuel pressure first; no sense in flooding the engine right off the bat if you don't have to. If the injectors seem to be opertional with battery voltage then pressurize the system and monitor fuel pressure as you test individual injectors.

When problems like this occur 99 times out of 100 it's because something you did caused the problems (this doesn't automatically mean it was your fault Just think about parts that were changed etc ). Secondary injectors could absolutely cause your problem and since they were recently removed, serviced and installed I think odds are good you'll find some sort of issue with them.

No Cones

I would bet AT LEAST a dollar that you have a secondary injector issue. Primaries are most likely operating fine as you have good driveability at low rpm and no boost. Just ground the secondary injectors at the ECU to confirm you can hear a click. No click, got a problem.

Btw, I had a suspected bad 2ndary, sent it to get tested and cleaned, it tested and flowed fine. I reinstalled and still had the same issue. After much additional (and needless, I might add) frustration I finally decided to replace the supposed good injectors. Voila! Problem solved.

fsae_alum

I also talked to a local RX-7 specialist/mechanic and he said that he has seen caes in the past where people have disconnected and reconnected the TPS harness connection so much that they actualy pushed out a wire or terminal in the connector and that led to the same problem.

He also told me that one easy way to tell that the front injectors are plugged into the correct harness connector is that the front harness connectors have white paint on them while the rear connectors do not.

fsae_alum

Update....

1.) Checked for codes and none present
2.) Started car and let it warm up for about 10 minutes
3.) Once warmed up and with the engine still running, unplugged and re-plugged the TPS connector back in (twice to make sure the ECU would catch it). When it was unplugged, the revs started bouncing around a tad bit. Smoothed back out once I pulgged it back in.
4.) Turned off the car and checked for codes....got a 12 and an 18 (TPS narrow and wide).
5.) Verified that pins on TPS look good as well as mating contacts on harness plug.
6.) Cleared codes.1
7.) Checked codes again and got an all clear from the ECU.
8.) Took it out for a spin and same problem as before with it falling on it's face.

Think this now rules out the TPS. That's all for tonight. I'll start looking at injectors tomorrow night. Thanks everybody!!

-Money

fsae_alum

Finally had some time to rip the UIM off and check thing sout. Verified that all the connectors were plugged in correctly and the vacuum lines were going to the right places and weren't kinked. Then I tested the Secondaries and bingo....no clicky. When I alligator clipped the two pins on the front secondary injector to the battery positive and negative terminals....no clicking at all.....even if I listen with an auto stethoscope with it beiong placed directly on top of the injector. Same thing happens to the rear secondary injector as well. I know the battery is good because I had my Battery Tender on it just before I started testing and it was showing the battery was good. Correct me if I'm wrong here, but I SHOULD hear a clearly audible click of the injectors when they have power and ground applied to them right? This sucks because WitchHunter cleaned and flowed them right before installation. Dammit.....

dgeesaman

iTrader: (7)

That's unfortunate. How long after the cleaning was it until they were used?

I have used a 9v battery and always get a nice click when testing the injectors. So unless there was background noise, I would assume they're stuck.

Just on the chance the harness was damaged - I would measure the resistance of the injector from the ecu pin to the main relay. That was also the circuit I used for my battery click test.

Dave

fsae_alum

dgeesaman...two days of shipping plus two days of getting the car all back together.

It was DEAD quite in my garage last night at 9 PM. I had all doors and windows closed just to make sure that I wouldn't pick up any background noise that would mask the injectors. No clicks at all. I've worked around DC solenoids long enough to know that they should click when hit with voltage and ground. Furthermore, it's typicaly a fairly audible click.

I checked the resistance of the injectors last night at the injectors and they checked out within spec. I'll plug the harness back in and check at the ECU tonight.

I just got off the phone with WitchHunter and they told me to give them a few taps on the top of each injector with a hammer to see if that frees them up as that usually does the trick. If that doesn't work they recommended yanking them out and soaking the bottom half in WD40. If that doesn't work, they said that they'd take them back and see what they could do.

The highly ironic part in all of this is that when WitchHuner did the flow test before the cleaning, they flowed with 5% of what they should flow.