danec020

Ok guys, this problem started when I redid my grounds, installed AC, and tried to find what was causing my timing problem. Which involved me removing the CAS and restabing it. I have always had a wierd timing issue, I Would set the Leading mark and the trailing would be way off its mark. Not even visible. But when I let it idle for awhile, sometimes (VERY RANDOMLY) the RPMs would drop and the timing would be dead on for both leading and trailing. But if I ever gave it gas then my timing would go off again (Even at idle, i know it is suppose to advance as it accelerates, but when it came back down it would be way off the mark). Because of this I believed it was a ground issue which has helped in the changing of rpms. Now it purrs and never fluxuates. But my timing is still wacky.

So now I have RTEK2, and I am loving it. I am still having this starting issue, and it is driving me nuts. When the car is warm it isnt nearly as bad, but when its the first start of the day it seems like it cranks then floods the engine out. I checked timing reading the Rtek was showing and this is what I have. To me it looks like my timing is really messed up because my trailing should be 15deg different than my leading or so I thought... Does this look right to anyone? If not, what can cause this?

Thanks
Dane

To clarify on the Graphs.. The numbers at the top are the inital values when I started the log. The first graph my timing was 15deg apart for some reason when i stoped at my house, but in the negative values and decided to take a log and see what happens as soon as I tap the throttle. that is the results, I tap it and let it go back down and it is just like the second graph which I will now try to explain.

Second Graph:
I had it idle for awhile and it seemed my timing was slowly winding down to Leading(11.6) and trailing(10.9).

Then about the 22nd tick from the right my leading(17.5) and Trailing(26.7)

Then all the way to the right on the third to last tick mark where my timing drops down, my leading(8.4) and trailing (-6.3).

HAILERS

The hard start could be attributed to the water thermo sensor being disconnected. If you CAN read water temperature on the Palm, then that's not the case. I mean reading cold when the engine is cold and around 180 when fully hot.

Another thing, when the engine is cold and you start it for the first time, and IF my memory serves, the lead and trail timing will be retarded approx 25 degrees. As the engine starts and warms up they come down/up/your terminology, to 5 and 20 degrees ATDC.

EDIT: Here's a jpg of what lead and trail look like during a cold start: https://www.rx7club.com/forum/attach...hmentid=173504

danec020

Thanks for the quick reply HAILERS. The water thermo sensor is connected and I can read the temps. Right now it is late but I will check tomorrow is my trailing is similar to that at start and then see where it is when warmed and post if results are different from what you stated.

Also a side note, I have done the TB Mod. I been fighting this issue for a very long long time and I don't know what else to check. I believe you helped me before with my other thread when I was having a fuel issue. I mentioned the timing issue as well in that thread (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/wierd-timing-issues-518887/) so I dont know if any of that info can relay to this topic as well but there it is for anyone else.

Thanks guys
Dane

HAILERS

Is this car a turbo conversion? From n/a to turbo?

danec020

No this is a 10th AE with original turbo, sensors, wiring, ecu, ect. All emissions have been removed and the motor and turbo has been rebuilt.

I think I can narrow down this problem some more. Today I kinda got lucky to find out the problem, but unlucky because the problem is probably going to be hard to fix. I was checking my cold start readings to compare with yours and everything was pretty close so I decided to try to restab and shoot the timing light to give it ANOTHER shot. Well I was in the process of doing this and when i grabbed the CAS to correct the timing the car died. The idiot lights stayed on but the engine died. So I started it up again after a lot of cranks. It caught and ran again, I then grabbed the harness where the alternator wires and cas wires meet and moved it around and the car died again. So after playing with it awhile I got the idle to change when I moved it a certain way and kept it there, checked the timing and everything was perfect. The trailing was on and the leading was on. I jiggled the wire a little and my idle raised and my timing was off again like my problem has been, and then if I moved it too much the car would die.

So, yes I have a short I believe. BUT what could cause my car to die? It couldnt be the alternator, because that would only cause the idiot lights to come on...correct? So my question is what could cause this? On a similar note, while I was recording data, my palm lost connection to the ecu (So it said). It has done this 2 times since I had the Rtek2.0. Is this just an error, or do you think it could be related to this ground issue, or the ecu ground itself?

I am starting to think that it is time to pull this dry rotted harness out and just spend the cash to get another or sit down for a few days and make one.

Anyhow, HAILERS thanks in advance for the info, I have faith in ya . BTW I checked the block ground and it was secure and read 0ohms so it was a good connection.

Thanks
Dane

dubulup

my guess is...in one position you have "okay" connection = L & T firing correctly

you wiggle, and have "bad" connection = L & T firing at the same time (if that is the case?!?...seems strange)

you wiggle some more and now have NO connection = nothing firing; car dies.

HAILERS

I've had the Palm stop working a couple of times. A pop up comes up iwth a message , in blue I think it says something about losing communication. So I tap the screen and it all comes back on. I think it's somewhat related to the alternator output because it usually happens while reving the engine.

It's mostly happened when logging, but the other day it happened when I was moving the slide bar for the ATP sensor. I think I was too ham fisted moving that bar and was confusing the ECU/PALM.

So it's not a isolated thing, the Palm stop working and a pop up screen coming up. It's not that common for it to happen either. Most days it never happens. I've go to make some kind of log each time it happens so I can really state exactly why/when it happens. I've come to the conclusion in the back of my mind that it happens because I've done something to induce it.

Just a thougt. The cas wires are encase in a shield. Probably because the CAS puts out a small voltage to the ECU and the shield is there to prevent any outside sources from messing with this cas signal. Like the alternator output.

That above might not be too clear. What it is, is the CAS makes the voltage signal going to the ECU. The ECU does not supply a voltage to the cas. The voltage is small and can be influenced by outside sources so the cas wires are encased in a metal shield which is grounded at one end, I think at the ECU side of the harness but you could gnd that shield at the cas end of the harness. Heck, I'm not even sure that's your problem. I shoulda quit while I was ahead.

danec020

Well I am pretty confident it isnt a short on the CAS itself. Because I swapped CAS with a friend when trying to figure out my fuel issue and the car ran exactly the same. Which I would assume it means there is a short on the harness side. I would think it would have to be relatively close to where I am moving the wires since there isnt too much play throughout the harness...

Well I will be back at it today. My Palm has only lost connection to the ECU while logging as well. Mine has always been while in neutral reving, never while driving. Don't know if it is the same for you.

Thanks
Dane

danec020

Ok, me and Dubulup were working on the wiring harness to see if we could clean it up and fix some breaks in the wires. I noticed the reason the car died when I wiggled the wires was because on of them cracked the insulation and would touch the block caushing it to die. So we took the harness out and checked the wireing, taped it up and took out the unneeded emissions plugs.

I was hoping this would solve the problem but still running the same. The idle starts at 5 and 15deg ATDC but after a few revs and it comes back down to 10 and 10deg.. I can't actually see the marks with a timing light, so i used the RTEK to get the degrees. It is showing +10 +10, so I am assuming that if BTDC? Since 5 and 15 ATDC is -5 -15 on the RTEK.

Also there was the yellow and red connector that came off the tranny harness, it was connected to a little blackbox with a ring connector on it. That box and ring connector snapped, was it plugged into the right location, and is it needed? It looks like the same box near the ignitors. I will see if I can get a picture off my phone to show you guys.

Thanks
Dane

EDIT: Picture of the ring connector.

HAILERS

The black item is a condenser meant for the oil pressure sensor circuit. I'd reconnect it even though the oil pressure gauge is working.

The timing should be 5ATDC and 20ATDC shown on the Palm as -5 and -20.

Notice that the timing will automatically be adcanced by the ECU once the rpms are over about 1100 rpm. At that spped the rpms will go BTDC and the minus sign next to the numbers will disappear.

Your going to HAVE to find those two timing marks on the pulley. The RTEK only knows what you tell it so to speak. You can set the cas just anywhere you want and the RTEK will THINK you set it on the timing marks and assume that where you put it is 5 and 20ATDC when it flat is not. So you must set the timing using the marks with a timing light.

I notice if I rev the engine for a moment and let it go back to idle, it takes about five seconds or so for the timing to return to the five and twenty numbers. In the meantime it'll before it settles down the numbers are close but not the five and twenty degrees.

You've gotta find the timing marks AND have the idle down close to 750 plus/minus a bit. Definetly under a grand for sure.

TDC can be found on the pulley if the marks are missing but you don't wanna go there. It requires pulling the front hub off, graph paper, a compass and a square. Trust me, those two nicks are there on the aft side of that pulley somewhere.

danec020

Thanks HAILERS for the input on the condenser. As for the timing I ment to say 5 and 20. I dont know what I was thinking. As for timing the car, I have done this many times. I do have the two marks, I have my idle set to about 750/800rpms. I got the timing for the leading and trailing to be dead on their marks. So as far as that goes, everything is fine.

NOW, as I was saying when I rev the car the timing advances but not like it should, unless it is correct and I just dont understand it correctly. The timing jumps to equal degrees, like I showed on the graph on the first post. So for example, when i rev to 1100/1200rpm my timing is showing on the Rtek 11 11. Which I would have thought it should show 11 26. Since the trailing should be 15degrees off from the leading. Is this correct? Or are the timing supposed to be equal durring revs?

The reason I was considering this a problem is because I will start my car and let it warm up. My timing will be on timed with the timing light and the rtek (-5 -20). I will rev it (maybe 2 or 3 times to get it to do this) and when my idle returns I am at 1100rpms instead of my 800 and the timing on rtek is showing around 10 10. I have checked to make sure there is nothing holding the throttle cables or causing it to stick, so I am assuming the rpm change is due to the timing going off and not from the throttle catching on something. This caused me to look at my trailing and leading time log, and I noticed some wierd timing issues on the spotts I circled. They seemed to be pretty much even all the way through but then one drops or the other jumps.

I am starting to feel that this is how the timing works, and that maybe something has to be catching my plates or something. IF you could post a run with your timing graph that would help termendously . I appreciate the help once again. I am starting to feel I am just paranoid.

Thanks
Dane

HAILERS

The bit where the revs don't return to 750 but stays at say 1100 or there abouts..........since its' not the cable then take a look at the thermowax if you still have it. I'd guess that the cam and roller are not seperating. keeping the throttle just open a hair.

IF you have the thermowax one way to see that this is happening is to look at the tps reading on the RTEK. Say the TPS was set so that it reads one volt dc when the engine is fully hot and sits there all day long with a hot engine. Well the next time this hanging throttle symptom comes up, look and see what the tps reading is. IF it's above the one volt it was set at, then the thremowax cam and roller are not seperating either due to the water temp not being up or????

The thermowax when cold will move the throttle linkage to open the plates just a bit for a faster idle when the car is cold. The tps is attached to that linkage so it will move also and you can see that on the Palm, especially in the morning duing the first start.

I never looked at the graphs. Sorry. Maybe later. The timing and the spread b/t the lead and trail don't stay fifteen degrees apart. I notice during a steady drive they might both be almost the same degree. Memory says I've seen say 35 degrees or so for both at a steady speed around sixth/seventy. Don't hold me to that. Its a memory thing. You get all sorts of spreads during different driving rpm/load/deceleration. Later maybe.

danec020

Ok, then it may be how the timing works for the plugs, and that they dont stay 15deg apart at all times. As for thermowax, it is all gone. I will mess around with the rpm change this weekend, it isnt a major concern. The big concern was boosting a car that the timing was going hay wire. But I am starting to think that the timing on both trailing and leading catch up to each other when in load.

Dane

HAILERS

At steady cruise they are about together. At full boost I saw the lead drop down to maybe 27 while the trail was 7. About 5-7000 rpm.

danec020

Thanks HAILERS. I geuss that settles it, the timing is suppose to catch up to each other in a steady cruise. So the only issue I am having now is just something causing my throttle to get slightly stuck. That shouldnt be too much of an issue. Thanks for all the help, learned something new and interesting .

Thanks
Dane