Blackfc3srx7

iTrader: (1)

I was wondering you posted in a thread about testing your secondaries by switching the primary pins with the secondary pins. My question is have you done that? And if so is it only idle and not any throttle that you can run the car at? I am troubleshooting like crazy and have searched a lot before posting.

Thx

RotaryRocket88

iTrader: (7)

<--- Not Hailers.

What are you trying to test? Are you talking about only running the car off the secondaries (primary injector clips on them, secondary clips on nothing), or swapping both pairs of clips?

You can get the secondary injectors to fire by removing the vacuum line to the pressure sensor, then revving the engine to 3800+ RPM.

HAILERS2

Do you have a link to the thread your referring to????

LIke 88 says, you can make the secondarys come online in the driveway by pulling the vac line off the boost/pressure sensor.........and if memory serves you have to pull the plug off the TPS also. And then rev to over 3800 rpms and they should come online.........but if memory serves when they do the tone of the engine changes for the worst.

I remember being kinda goofy once and what I'd do is get on the hwy with the boost sensor vac line off and drive on the interstate like that with the engine over 3800 rpms for miles. Supposedly to get the secondarys to operate for a long period of time. Like excercise them in a manner of speaking. Just something to do type thing.

ALSO:

I vaguely remember swapping the wires on the ECU plug. Like swapping the primary with the secondarys wires and then starting the car. It ran but if memory is right after I pulled out of the driveway about then feet I decided that this sucker ain't a gonna get me around the block, so I put it back in the driveway and put the wires back where they belong.

Really does not take more than a few minutes to do something like that if your curious.

What's your problem your trying to fix?

If you have a meter you can backprobe the secondary injetors and look at the voltage. It will be alt voltage til you get over 3800 rpm and with a load on the engine the voltage will drop down from approx 12-13 to 7-8 vdc when they come on. Can only do one at a time unless you use two meters.

HAILERS2

There's one other thing I've done before that I can't figure out. I swapped the primary wires only b/t the front and rear rotor and did drive the car on the hwy. I couldn't tell the diff from having the wires on right or wrong. I decided to put them back to stk. Odd. Almost seems they batch fire for that to happen. I lost interest in finding out why the car acted the same stk or wires swapped.

I do know the secondary injectors batch fire...........but the primarys?

satch

iTrader: (1)

His problem from previous threads.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/help-i-need-figure-out-926949/

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-n-fuel-lean-issue-951886/

Blackfc3srx7

iTrader: (1)

Thanks guys for responding! Also satch for posting the links. HAILERS I can't find that thread again but it was about the 3800rpm hesitation and you mentioned swapping the pins at the ecu. I have the secondaries hooked up to run as primaries still in the top rail spot of course. I basically get a 3800rpm hesitation even when the tps and boost sensor unplugged. I get the car to start and idle with the pins switched however when I press the throttle just a little it chokes and can stall if I don't let off. I have replaced fuel pump and get 40psi for my fuel pressure. So that is where I am at and I have had the injectors cleaned when I rebuilt the motor 3-4 thousand miles ago. I don't see the voltage drop when metering goes from 13 volts - 11 volts.

HAILERS2

voltage drop when metering goes from 13 volts - 11 volts

For some reason I don't understand what that means. I know if one is actually driving the car under load and hits the 3800 rpm, that the voltage that was shown on the secondary injector wire (generally b/t 12-13vdc steady) will now drop pretty far. Usually I saw seven or so volts from my memory. The voltage drop shows the secondary injector being looked at has opened.

How far the voltage drop depends on how much of a load is on the engine.

IF you had some money to throw at this problem, you might try a FJO injector driver http://www.fjoracing.com/products/injdrvr/ about a hundred fifty bucks. Do a search for FJO injector driver on the RTEK forum.

The installation is not quite what they say in that link. The wiring is done at the ECU plugs and no injector need to be accessed.

I did this for fun after reading about the FJO on the RTEK forum. Only slight side effect seems to be I get some backfire when I let off the pedal at times. This did not exist prior to the FJO install. Frankly the thing is just laying on the floor of the car near the ECU for the last year and it's not a tidy install. I need to tidy up a bit in that area.

If I were you I'd give it a shot if you don't mind doing a little soldering......extract pins from the ECU type stuff. Might just do a temp install to make sure it works/helps prior to a tidyed up install. What's a hundred fifty bucks? A couple of fillups at the gas startion?

I bought mine from Alamosports or some name like that located in San Antonio Tx. http://www.fjoracing.com/products/injdrvr/ again they make toooo big a deal about the install. We all know the injector wire colors and which plug they are on. Just have to find a source of switched 12vdc to drive it and a good gnd poiint. I use the ECU mounting bracket studs.

I'd give this a shot before selling/junking/burning the car. Seems you've tried the other remedys for hesitation. Althought that said the extra gnd for the ECU worked for me and also NZCONVERTIBLE and others. Some not though. Pins 3A, 3G, 2R and ??? forgot the other.

Blackfc3srx7

iTrader: (1)

Ya the when measuring the voltage drop I am giving it the beans if you watch Top Gear. But don't see anything below 11 volts at the time the secondaries kick in. Main question is does that mean that the injector driver isn't working? I saw the link and I will check it out. I want to try to get the stock system working because there has to be a solution. I just don't get how this happened randomly. I had the fuel filter reversed and didn't know if maybe the injectors got damaged. I just don't have the voltage drop so that questions if the driver is working or the injector coils are messed up even if they click.

turboIIrotary

iTrader: (9)

Are you talking about this thread? https://www.rx7club.com/2nd-generation-specific-1986-1992-17/power-drop-noticeable-hesitation-issue-high-6300-rpm-802779/

Karack mentions switching secondary and primary pins at the ecu and he finds out that there was a bad wire causing the hesitation.

Blackfc3srx7

iTrader: (1)

Yup that is the one. Both injector wires B/Y and G/(different color depending on injector) read battery voltage and the G/(different color depending on injector) will drop to 11 volts at full load. With a screw driver and reving I could hear them click at when they were supposed to but still a lean spike.

HAILERS2

Frankly I'm having a BITCH accessing this site and responding on this site. It's infected in my mind.

HAILERS2

To get to the second gen I have to first access the third gen then go from there to the second gen site and if I respond with a reply to a thread it almost never *takes* so I log off and can go anywhere else on the web with no problems at all. this site is infected in my paranoid mind.

HAILERS2

Sounds like the secondary injector driver if the voltage never drops under 11vdc when the car is being driven under Load over 3800 rpm. Try looking at both secondarys doing that. FJO can't help that problem.

HAILERS2

Even in the bad old days when I had hesitation I NEVER saw as small a voltage drop as your seeing and even when I did have a hesitation problem it always recovered after the 3800 crossover.

HAILERS2

Your backprobing the light green/red or the light green/white wires at the small plug on the ECU, right? Tried both one at a time?

HAILERS2

Swapping wires b/t primary and secondary means the injector is injecting in the intake manifold instead of the intermediate housing and in my opinion that makes for a very undrivable car even out of the driveway. That's from only one experience doing this in the past.

I've never actually driven a car in that configuration. Just reving in the driveway watching a meter won't cut it imho.

Blackfc3srx7

iTrader: (1)

I only have one meter so only did one at a time. The primaries drop the last time checked them. Makes sense on running it only on secondaries just didn't know if by slightly reving it and it stalling gave a sign that the injectors were falling on their face and it was the injectors themselves. I also wanted to confirm that you use a digital meter and can consistently see the voltage drop since I know on a (analog meter?) that it can show a sweep better. That is what I have read on this forum. I am just trying to figure out if it is a wiring issue even when I have voltage on both wires on each injector, an ecu problem even though I have 2 to check it, or bad injectors somehow. I do have injectors on the way because I figured why the hell not after replacing the 20+ yr old pump. Its still running good for my first ever engine rebuild so I hope I can just figure this out so I can daily drive it again.

Blackfc3srx7

iTrader: (1)

Alright got some new injectors in for secondaries and still has a hesitation. I did meter it and pushed it to the flow and had the primaries only drop to 9volts is the lowest I ever saw and the secondaries once dropped that low. I am wondering if the what my next course of action should be? Maybe look at the main relay? Any thoughts?

HAILERS2

I never used anything other than a digiatl meter. The Fluke 88 can capture the high/low seen by the injector.

Sounds like you 've got the regular hesitation seen on this forum and for some reason grounding the ECU gnd wires (additonal ECU gnd wires) etc does not work for you .

I usually would go out on the hwy and drive up a long grade and step on it. That creates a load higher than normal and usaully that causes the primarys to drop pretty far down before the secondarys come on. What happens is the primarys might drop down to say 4-5v and when the secondarys come online the primarys will rise up at the same time the secondarys drop down from batt voltage. Then they both read the same voltage as you keep on keeping on with the pedal down.

Got me what to try next. If you have spare dough try the FJO. I did mislead in my last post on FJO. It was more or less a eady install for me 'cause I had a spare bits of a old harness and I cut four wires at random off the small plug on that harness and spliced those wires to the four of the FJO wires that connect to the harness. Then the original four wires that Were in the ECU got soldered to the other four FJO wires. I left the terminations on those original wires in place and soldered the terminations to the FJO wire. Later when I get around to removing the FJO I can just heat up those terminations til the solder runs off then and then plug 'em back into the ECU plug.

May sound like a crummy install but I just wanted to see what a FJO would do for the car and then remove it later.

Just saying I didn't have to cut any stk harness wires doing it this way. But if someone didn't have spare wires/terminations laying around he'd have to cut and solder to the original injector wires that go into the small ECU plug.

HAILERS2

You might check to see what is happening with your alternator output when your hard on it. See if the alt is still in the 13vdc range when your having hesitaiton problems. A good place to look at the alt output is the pure black wire on the igniton switches pigtail. That wire comes directly off the alternators output wire. It's in a two wire connector at the switch and is paired with a black/white wire.

Looking back maybe I've been too flip when talking about watching the voltage drop on the secondarys. I've that Fluke 88 that has features like capturing the high/low reading of whatever your looking at and that makes life pretty easy. Watcing a regular meter without that feature might make it more difficult.

Seems I did watch the face of the meter while driving and could catch the drop/rise visually without going back looking at the capture feature of high/low. Its been a couple of yrs since doing that. I don't do it on a regular basis .........'cause I've no problems and there's no need to do it.

Blackfc3srx7

iTrader: (1)

I will try to test the alternator soon. I had it tested at Napa along with the battery a week or two ago. Thx Hailers. I don't know why this happened since I had it running great even daily driving it for a long time then it started to lean out at light cruise more that normal then develop the hesitation. I can right now floor it and it will peg to 16ish or higher at 4 grand then go back. At light throttle like 2 grand in 4th I get afr of 15-16 which is strange since I had to lean it out before to get it that high.

Blackfc3srx7

iTrader: (1)

Alright did some monitoring of the voltage when driving and doing pulls but no drops in voltage coming from alternator. I do notice that I can easily get the hesitation when in second and just going WOT and then it stutters at 4000rpms. I am wondering if my secondary ports don't open and the mixture isn't right can I get a super lean reading versus a rich at that point? It usually reads 16-17 when stuttering bad.

Blackfc3srx7

iTrader: (1)

So after doing some light cruising I am pretty sure it is vacuum related. In 4th or 5th gear light throttle, 2200 rpms, I see the afr go to 15-16+ and my vacuum goes from around 20 to 10-12. This makes me believe that there is a vacuum leak that is more apparent during driving. Does that make sense?