juantii

Hi, I just rebuild my Turboii 10th AE engine with fresh seals and springs compression is at 100psi. and before the rebuild the engine show no flooding problems but now it is because I installed a toggle switch to kill the fuel pump while cranking and the engine starts everytime by doing this only, if I don't use the switch to kill the fuel pump it wont start when hot but it will sometimes when it is cold, the idle it's a bit erratic also but I am guessing it has something to do with fuel flooding problem also...any ideas where to look for please help?????

jjcobm

iTrader: (18)

Leaking fuel injectors sound like the problem, but you do have an erratic idle too so it sounds like a combination of leaking fuel injectors and POSSIBLY a vacuum leak somewhere. Although if your fuel injectors are leaking bad, the idle will be erratic.

Get your fuel injectors cleaned and tested, it is very common for this to happen. Series 4 Rx7 are even more prone to flooding due to mazda's design of electronics.

I have not rebuilt an engine myself, but from the people I know who have, if you used used rotor housings on your rebuild, the engine will be prone to flooding for the first few thousand miles due to the low compression and seals not "broken in", so you may be experiencing that issue if your injectors are in good condition.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/hot-start-problem-1990-rx7-egi-n353-651715/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/intermittent-hot-start-issue-even-after-new-engine-rebuild-686893/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/looking-car-has-hot-start-problems-499744/page3/

I am sure if you search HOT START on this forum, you will find plenty of information. Hope this helps you.

juantii

thanks for your help I will begin with the injectors and see where that takes me I'll be posting any results........

juantii

ok so I sent the injectors for cleaning and flow testing and they all flow the same amount and they don't leak, they were tested at 55psi and they don't leak, one thing I didn't mention before is that the engine was street ported but I don't think this has anything to do with the flooding problem because the compression is within specification......Please help me with ideas on where to look for, could it be the Fuel Pressure regulator for the primary injectors? I already double checked all the vacuum lines for any loose or broken little hoses but they are all ok and well connected, the watertermosensor looks fine and I've been told this sensor when its bad the ECU reads a signal like if the engine is hot and I am having flooding problems at both cold and hot temperatures the only thing I have notice is that it sometimes starts when cold without using the toggle swicth to disable the fuel pump but sometimes I have to use the toggle switch even cold so I am guessing the water sensor has nothing to do with my problem????????

diabolical1

iTrader: (3)

are you using the OEM injectors and fuel system or do you have aftermarket parts?

also, if the compression is good, as you said, the i would probably check your coil ouput, timing and ignition wires. the streetport in and of itself should not be causing the erratic idle, so it's good to know, but probably not too relevant to what you're experiencing.


also, i know this might seem dumb, but just for clarity, when you say fresh seals and springs, you are speaking of all the seals, and not just the apex seals, right?

jjcobm

iTrader: (18)

Take a look at that. How many miles have you driven your car? Did you use used rotor housings? If so, that is your problem.

juantii

new (Rotary Aviation) super seals apex seals and springs, new OEM side seals and springs, new (solid Atkins rotary) corner seals and springs AND yes I did use my used rotor housings because they sho no apparent wear or damage and the fuel system is all stock including injectors and fuel pump, the Turboii has 800 miles on it with the fresh engine.

thanks for your help.


I answered to your questions at the above post and thanks for your help I checked the links that you gave me and there is a lot of info there even though I feel now like I have wasted my money on this rebuild if only I knew this series 4 RX-7 were so prone to this flooding problems I would rather got a series 5 but I guess is to late for bitching now...

jjcobm

iTrader: (18)

Drive the car 2,000 miles. Like the experts report, it will go away by then if it's due to the housings.

How is your idle? It should be steady at around 750rpm, it may fluctuate a bit, but shouldn't by more than 100rpm. If it is still bouncing like crazy after checking the injectors, I would look at vacuum leaks or adjust TPS.

juantii

one thing I noticed today is that the car's erratic idle has something to do with the flooding, it floods when is idling at 750rpms because it stalls after a minute or so at this RPMS and only keeps running when its at or above 1000rpms, when it stalls it is hard to turn the engine on again and I have to be toying with the fuel pump toggle switch until I get it running again, no matter what I do with the BAC valve and the (leaner or richer) screws to keep it stable at idle it only does so for a few seconds or a minute if it is at 750rpms......could it be a vacuum leak or false air entering the engine from some other place than the air flow meter?????

jjcobm

iTrader: (18)

It sounds like low compression at low rpm due to used housings causing flooding, I would keep driving to 2,000 miles and check back.... Vacuum leak would run lean and not flood, and you would not be able to bring the idle down under 1,000 rpm due to the extra air entering your engine, BUT it is possible it is a vacuum leak you have. Spraying carb cleaner around the engine intake manifolds and seeing if idle jumps up is a good way to check for vacuum leaks. If you didn't use new intake manifold gaskets, that is a source. If you didn't cap off unused ports or routed a vacuum line wrong, that would cause irratic idle. Unadjusted TPS causes irratic idle also.

My best guess. I would love to know what the expert engine builders think.

juantii

will check on that..thanks!!!

Guys I am really desperate with this flooding problem that I have since I haven't been able to give the car some break in on the engine because it stalls at idle because of the flooding(I can get it to have a smooth idle it just do fine for some minutes then when I leave it idling after a while it stalls and it is very hard to get it running again)it only stays running for hours when I have it at 1,200rpms or up but when I set the idle at 750-800rpms it runs fine for a while and then it stalls and its a hell to get it back running, I have the fuel pump switch installed and the line that goes to the ECU the (black and blue wire) disconnected so it does not inject fuel to the engine but it is still flooding, what keeps me concerned is that I am guessing it floods while the engine is idling because when it stalls the only way to get it running again is by pulling the plugs out and cleaning them, I am willing to pay a reasonable Fee to anybody through PAYPAL that can lead me to the solution of the problem.
Thanks!!!!!!!!!

jjcobm

iTrader: (18)

If the engine is cutting off, you have a problem. The flooding should only be there when starting the car, not while running. Sounds like a sensor isn't connected properly causing the engine to run hell rich. I will ask a mod to move this thread to the second gen main to get more attention.

juantii

Thanks a lot for your attention, at the beginning I thought it was only flooding when I was starting the car but now I don't think so because it is very hard for the car to stay idling at factory level rpms. and when the car is doing so(because I can get it to idle fine for some time even though its hard for me do to do it) and it stalls after a while that it's idling I am positive it is flooding because most of the time I can't get it running again until I get the spsrk plugs out for cleaning even though I am using the fuel pump switch and ECU line disconnected. I guess that if it was a engine compression problem it will flood everytime I try to start the car but I am having problems to keep the engine idling also. I have a wideband sensor installed also and it reads 11.8-12.3 A/F ratios at idling if this could help.

jjcobm

iTrader: (18)

Meanwhile, the first thing I would do is make sure all your sensors are connected, especially the AFM (air flow meter).

mar3

iTrader: (8)

Who's got the TII mojo to crack this one...?

juantii

can anyone help me on this? things to look for or check?

HAILERS2

If when you check codes you don't have one for the water thermosensor then it's probably ok. You only get a code if the circuit b/t the sensor and ECU is open.

If it were just a cold start problem I'd say look and see if pin 3B on the ECU is seeing the START signal when the key is HELD to START. If it was not there then that would explain a problem with COLD starts but not hot starts. ....although if it were just hot start problems the LACK of the ECU seeing a start signal would actually help the hot start problem. But then again you have hot and cold strart problem so it's probably not that. It would never hurt to take a few minutes to look and see if 3B is getting that Start signal with the key HELD to start.

You might check out what the fuel pressure is at idle when the engine is fully warmed up and IDLING. That might be a clue as to the dieing when at idle.

The 3B can be checked without going to the ECU , in a round about way. These cars at one time had a SubZero motor located near the wiper area. It had a two wire plug and the wire colors in that plug were both Black/Red. ONE of those wires will reflect the start signal when the key is HELD to START if the wiring has not been compromised in the past. Try one wire at a time. I think it's the one that's at the top of the *tee*, but I might be wrong about that.

Got any codes at all????

Might be the ported engine???? Mabe they need a bit higher idle speed. I'm not sure of that one. Just a guess and nothing more or less.

juantii

How can I check the codes? The 3B pin is getting the signal... fuel pressure is at 38psi at idle.

jjcobm

iTrader: (18)

http://www.banzai-racing.com/FD&S5_error_codes.htm

Look at the top where it says Series 4 FC's ONLY!!! The procedure is the same, but the codes are different. Your's is an s4.

Good luck!

HAILERS2

Your fuel pressure is a touch high at idle. A normal RX idle fuel pressure is 28-32 psi. I'd check and make sure your FPR is getting vacuum on it.

This probably does not solve your problem, but it's abnormal according to the FSM.

juantii

the primary rail has a mechanical FPR right? so I should be checking on the secondary injectors rail? if this is true I already check on this and I apply vacuum and pressure to it and nothing seems to happen but I don't know if I am doing it right........

juantii

thank you I will check on it.......

satch

iTrader: (1)

When the car is idling and you pull the vacuum hose from the FPR, does the hose have vacuum on it? There should.

HAILERS2

On a stk car that is a pulsation damper. I'm talking about the item that has no vacuum hose on it. Pulsation dampers don't regulate pressure at all.

The FPR is the one with the vacuum hose. No vacuum on it means the rail pressure (both prim and sec) should read approx 28-32 psi at a rpm of 750-800 rpm. The FPR on a turboII series four is on the secondary rail at the rear of that rail.

Let's say it does not and you reconfigure til it does. Sorry, but that won't help on a hot start problem. MIGHT help on a idle problem though. maybe

A stk USA version looks like the attached jpg.

juantii

will check it tomorrow morning