2Lucky2tha7

iTrader: (3)

Hey guys,
I just finished my 4 month long project of porting and rebuilding my engine. I spent all this time MAKING SURE that I did everything correctly (as usual) and performing as many performance and preventive maintenance procedures as possible. Now, after putting 190 miles on the engine, I have noticed a few very persistent problems:

1) The car starts pretty good when cold (almost normal), but BARELY starts when it's hot (takes about a few minutes of cranking over and pushing the pedal and it just BARELY catches).

2) It has a problem holding a low idle. I adjusted the throttle stop screw on the primary throttle plate so that it can hold a 1500 rpm idle. It will randomly hold this idle, but alot of times, it will just stall itself out, and I'm left having to crank it over for minutes on end with the fear of being stranded with a dead battery!!!

3) My brand new Magnaflow high flow catalytic converter is CONSTANTLY glowing at idle!!! Sometimes, a small portion of the y-pipe near the catalytic converter glows as well.


These are my mods:
*Series 6 rotor housings in great condition ---> ported exhaust.
*primary, secondary, and auxilary ports ----> large porting (do not ask me if I messed up the porting because I researched thoroughly before I even started porting) The primary and secondary ports open up MUCH earlier than stock, and close a little later. Auxilaries are LARGE with Pineapple sleeves inserted and smoothed out to match my porting. Overall, my intake and exhaust parts are quite large.
*port matched and slightly opened intake manifolds.
*TII oil pump
*RB street oil pressure regulator
*Rotary Aviation apex seals with OEM springs
*OEM side seals and springs and corner seals and springs
*RACING BEAT header
*Volvo electric fan
*TB mod
*S-AFC
*a bunch of other **** I can't remember right now

I've tried setting my timing, but it's extremely hard to do when I can't get the car to hold a steady idle below my 1500 rpm setting. I am pretty definite that it is correct though because I've watched the timing marks with a timing gun when the car idles down and dies out, and during that span of 1-2 seconds, the LEADING timing mark matched up while it stalled out.

I originally set both TPS's (NARROW and FULL) exactly to spec after I set the throttle plates to their factory closed positions (with the cold start "plunger" on the TB "disconnected" (I stuck a screwdriver in position where it held it open so that the primary throttle plate would fully close. Then I manually adjusted the primary throttle stop screw temporarily so that the engine will idle around 1500 rpms.

The only engine code I get is a random code 17 (feedback system--->usually has to do with the 02 sensor)

I used an ohmmeter and checked both TPS sensors as well as the BAC.

I used 19 feet of 4 gauge wire and made a very strong and secure ground system that runs from my ECU-->chassis-->engine block-->body of alternator-->negative(-) battery post. I also ran a 4 gauge wire from the positive(+) side of the alternator straight to the positive(+) post on the battery.

I tried richening the low rpm area on the S-AFC to aid in startup when hot, but had ZERO effect!!! (I am using an Innovate Motorsports wideband monitor).

The car seems to run great aside from these problems.

Oh, and by the way, there are no vacuum leaks (so please don't try pointing this out).

And no, the engine is NOT FLOODING becase I've checked the plugs and they were never wet. It seems it's not getting enough fuel at startup when hot.

I've searched like crazy and I've practically exhausted my efforts in trying to solve this problem, and I feel I am coming to a dead end.

So, with all that being said.............. what the hell is wrong with my car?!?!?!?!?

Brian

neu

oh god that's a lot to read (i only read the top paragraph ) sounds like going on the idle thing and the extremely hot exhaust.. it seems like you're porting is causing it... since you're breaking it in.. it's gonna be tricky, it might be part of the break in process you will have to go thru.. i dunno im confused i just read the top and skimmed the rest, but it's got something to do with the porting im sure, the intake is wanting to pull too much air, and i bet if you could get it up high rpm it would be different.... hrmm the TB mod probably isnt helping with the idle problem either, you have the safc.. so you could adjust fuel to be rich... did you adjust the variable resistor? since that mainly effects idle.. try turning that to full rich.. if you havent already... get your a/f matched up at idle to see if it makes any difference with it at all... but since you're in the break in process i guess it could be a little while before you will really know what the problem is..?

neu

not sure but i think i read that people with mod's like yours cant hold an idle below 2k?

user 36859

Damn that sucks....

It sounds exactly like my RA seal problem.... Get a compression test...

good luck,

1987RX7guy

iTrader: (3)

Even though you believe your car isn't flooding I would check your fuel injectors for dripping.

Icemark

Pushing the pedal at all when starting suggests flooding or other simular issues.

As well as the poor sub 1500 idle suggests a vac leak (what makes you think there is not one??? Since you are claiming that is not the issue. Have you sprayed down the external intake lines and vac lines with starting fluid to confirm)

Do you have a BAC and is it hooked up???

2Lucky2tha7

iTrader: (3)

To answer some questions, etc:

1) The car will sometimes hold an idle all on it's down to around 700 rpms, but it will eventually stall out. Sometimes it's at a steady 1000 rpms or 1200 rpms. I know the engine ITSELF will hold factory idle (700-900 rpms), but it's just a matter of how to get it to stay there consistently.

2) As for the RA seals? I have the newest batch of them, and once the car is running and moving, it's runs great!! I will perform a compression test later on after the engine has been broken in more.

3)I highly doubt that any of the injectors are leaking because once the water temp sensor registers that the engine is cool, the car pratically starts right up because the ECU is having the injectors dump in more fuel. I've already checked all 4 spark plugs after cranking the engine over for a few minutes and not a single spark plug was wet whatsoever.....or even close to it. Not even the smell of fuel (maybe a little bit of course, but not enough to convince me even close to the fact that it's flooding.)
I have also been running REDLINE FUEL INJECTOR CLEANER just incase the injectors are clogged or dirty. I know for a fact that this stuff works AWESOME, but so far I haven't noticed a SINGLE bit of difference yet (200 miles so far). Also, all of the injectors ARE working.

4) Like I said before, there are NO VACUUM LEAKS because first of all, I ran all brand new silicone vacuum hosing in the car, every hose is connectly correctly (I've double checked the FSM also), and I've already pulled off the manifolds to double check for vacuum leaks. I also used all brand new gaskets, and no, there is not a wire, hose, or washer pinched between any of the manifolds that would cause a vacuum leak in case anyone asks this.

5)All of the emissions equipment is still intact and I have check the operation of the BAC valve and it is working properly. The resistance values on the BAC are also within spec.

RotaryEvolution

iTrader: (30)

i have the same problem, i have ruled out all sensors and i can only start the car with the accelerator at the floor and using my fuel cut switch, only thing it can be on mine is leaky or partially sticking injectors. after having the engine apart about 3 times it has always had the same problem so i also ruled out the internals as a fault as well.

F1blueRx7

iTrader: (5)

https://www.rx7club.com/showthread.p...&page=19&pp=15

There are reports that there is still some questionable seals floating around out there. I'm really afraid of having this hot start issue I was under the impression that all the seal issues were worked out.


How did you break in your motor? How many miles are on it now?

Icemark

A pour in Fuel injector cleaner will not clean injectors that are so dirty that they are leaking. The injectors would need to be removed and professionally ultra-soniclly cleaned. And there is not one pour in injector cleaner in the world made that will clean the 2ndarys, unless you spend most of your time above 4000 RPM.

New gaskets and vac lines generally increases the possibilty of a Vac leak by 100% unless you have built and re-assembled more than a couple engines.

If you spray all the external intake manifold joints, injectors, and vac lines with spray on starting fluid while the engine is running does the idle go up???

Good, we should be able to rule that out then, provided the ECU is working correctly. However if the BAC was tested while plugged into the ECU with a test light or anything but a digital multi-meter, the ECU maybe internally damaged and cause the problem you describe.

Maxthe7man

hmmmmmm...... Get it warm and do a compression test.....

F1blueRx7

iTrader: (5)

OEM springs? dont' the RA's use their own 2 spring setup? I'm not familiar with stock mazda seals.

Maxthe7man

Yeah they do, but supposedly the hot ticket is the oem springs with ra seals, but if the seals warp, doesn't matter what spring is under them..It might not be every set, maybe just every odd set, who knows, no enough long term testing out there yet to convince the jury..
His problem could very well be something else, but when you have an engine running/starting/tuning problem its always best to start at the engine and rule that out, before going anywher else, and not only that its very quick to do, I have seen enough cars with shitty engine builds get patched, stand alones installed and parts changed and still run shitty to be confident in this approach..There is no sense in changing or messing operating systems if your computers hard drive is dead right?..
Start at the engine and work backward, once thats out, its leaks/electrical/or setup...

F1blueRx7

iTrader: (5)

i have a small idle issue when hot, but I think it's really a TPS related issue that I just need to test out with the lights. Other then that I used the seals on new housings and it pulls damn hard with the SP.

Maxthe7man

Yeah mine made good power as well, right to they day I pulled apart, when it was running it was fine, its when it was hot, and I shut it down, it was a bear to start, towards the end there, it was taking nearly a minute of cranking to get the car to start, it would slowly start on one rotor, then pick up from there...

2Lucky2tha7

iTrader: (3)

UPDATE:

I have about 1400 miles on the engine now and she starts right up regardless if the engine's hot or cold. About a week ago, I tried advancing the timing, but I started hearing slight detonation around 4500 rpms and higher (of course, everytime I started hearing it, I backed off the throttle --- this was when the engine had 500 miles on it). When I advanced the timing anywhere between 5 - 10 degrees past the stock leading mark, she started up MUCH, MUCH easier when hot, but obviously started detonating around 4500 rpms!! So, I kept it around 10 degrees advanced when the engine had 200 miles on it, up to about the 500 mile mark, so I could start the car up more easily when hot. This is when I started hearing detonation past 4500 rpms, because I was now starting to rev it a bit higher--- about 5000 rpms. So, I backed off the timing to about 5 degrees past the stock leading mark on the pulley. Now, I only heard it slightly detonating every now and then around 4500 rpms, which of course still frustrated me. So, I backed it off a hair to about 3-4 degrees advanced and it basically went away. I kept it like this up to about the 1000 mile mark.
(NOTE: I was constantly trying to keep the timing slightly advanced like this because it would start up much easier when hot).
At this point I was revving the engine up even higher, but it just didn't feel right, so I backed off the timing to about 1 degree advanced past the stock leading mark, and so far she has been running very well. I had hopes of advancing the timing to gain more power, but for some strange reason, I would only get signs of detonation. I've read that a few people on the forum have advanced the timing as much as 10 degrees with no ill effects, but for some reason, I do. Is it because my ports are soo big?? I mean, I did open the intake ports up much earlier than stock ---I ported the farthest "back" that I could on the primary and secondary ports without affecting the side seals, and I opened up the auxillary ports quite a bit--- later port closing timing. I also ported the exhaust ports larger than stock---I ported "upward" a bit, as well as "downward".
I still have my idle set screw on the primary buterfly set so that my idle stays around 1500 rpms when the BAC is on. When the BAC turns off sometimes when the engine is idling, it holds a relatively steady 600 - 900 rpm idle --> sometimes it's 650-700 rpms, 750-800 rpms, or even 850-980 rpms. (Reading from the S-AFC). I have also been using an AFR monitor the entire time, and so far my settings are as drastic as -22% in the HI THROTTLE correction screen on my S-AFC which results in low to mid 14 AFR's at WOT from 3000 - 8000 rpms!! Also, if it makes any difference, in the ETC. section of the S-AFC, I have the correction ratio set to +/- 30%. I also have my throttle points set to 20% for LO THROTTLE and 90% for HI THROTTLE.
I also believe that my engine has the appropriate stock pulley from the factory and that it has never been swapped out in case anyone is wondering about my timing marks. Before I rebuilt the engine, it appeared COMPLETELY STOCK and nothing was ever messed with. Everything was intact and where It should have been.

I would really like to set my idle lower, but I'm not exactly sure of how to correctly do that at this point. I take it that the BAC always stays on at idle in order to keep it idling??? I mean, from the factory, the primary and secondary throttle plates are COMPLETELY CLOSED!! Should I close the primary plate, re-adjust the TPS switches and adjust the idle screw on top of the throttle body to fix this?? I know the engine will definitely hold a low idle, but I guess it's just a matter of getting it there.
Anyone have any input??

Brian

2Lucky2tha7

iTrader: (3)

I've also noticed "black rings" around my new spark plugs (9's all around) that are ash-like right around where the numbers are printed on the spark plugs. I guess this is caused from bad spark plug wires?? I've just never seen this before. 2 of the trailing plugs have this, as well as the front rotor's leading plug.
Any ideas??

2Lucky2tha7

iTrader: (3)

anyone??