jamespond24

iTrader: (13)

When turned ignition on with a multimeter it read 12V on 4 side of the injector clips(primary & secondary), is it suppose to? I been having 3k rpm bucking, hestitation problem so does it mean my secondary is not getting ground signal from the ecu for pulsing? If so why is the primary working fine?

RETed

Yes.


-Ted

hanman

If your secondaries don't come on at all, it is one thing. If it is just the hesitation at 3800 rpm, it's most probably grounding.
There are a couple of fixes for the hesitation, look around and you will find them. But, before you do that clean up the two grounds on the engine. They are both under the upper intake. One is the harness ground that controls the fuel injection and goes to the ecu, the other connects to the back side of the firewall.

Then, I would do the ground wire to the boost sensor as the factory recommends.
If that still doesn't work, I would run a new ground at the ecu. Do a search there is a write up on it.
But, I am guessing the car will run right before you ever get that far.

Dustinali

iTrader: (10)

His injectors read batt voltage on each side of the injector clips. He gets 12v on the hot side (black/Yellow) and on the ecu driver side to the injectors. I think it might be a grounding issue too.

jamespond24

iTrader: (13)

So is this a grounding issue?

jamespond24

iTrader: (13)

ttt

HAILERS

What year car is this????? Is this a series four or five????

Is your boost sensor connected up and have a vacuum line going to it?

Again, what year car? Series?

hanman

Dustinali, why do you say he has 12V on each side?
I think what he is saying is, that he has 12V on one side of each injector (4). Which is correct. You only see a pulse on the other side when the car is turning over or running. And you wouldn't see the pulse on the secondaries until they kick in.

scrip7

iTrader: (6)

If he is checking the voltage with the harness still plugged into the injector (as in back-probing), he will show voltage on both terminals (the injector is a wirewound coil inside). With the harness plug disconnected, you should see volts on one terminal only, the control unit pulses the other one to ground.

jamespond24

iTrader: (13)

Dustinali posted is correct there's is 12 V going into both wire on each clip. I know there's suppose to be one 12V read on one side of the injector clip but I have both wire read voltage on a single clip.

jamespond24

iTrader: (13)

Thank you! So for my car bogging at around 3K at 5lb. boost is has to do with grounding? I'm going to clean and run new ground wire today.

jamespond24

iTrader: (13)

S5 TII

jamespond24

iTrader: (13)

I did everything mention on this website and still have the same problem. What could it be?

http://www.aaroncake.net/rx-7/grounding.htm

scrip7

iTrader: (6)

Although grounding problems are common with FCs, poor grounds are not the only thing that causes bucking and hesitations. As with any EFI system, having proper fuel pressure and volume is important, and with that in mind, there are writeups in this forum for fuel pump voltage and supporting mods, so do a search for that. Also, certain sensors can develop "glitches" within their ranges of operation, for example, the TPS and MAF sensors both have potentiometers that can fail and cause your symptoms. The best way to check them is with a lab scope (at most dealers and high-end repair shops) however you can use a multimeter but most won't catch glitches due to their slower baud rates. Does your engine idle smoothly? Did this happen all at once or come about gradually? Also I wouldn't rule out the possibility of dirty/ clogged secondary injectors or fuel filter. Check the intake boot from the throttle to the MAF sensor for cracks and loose clamps. Check that your spark timing advances smoothly as you accelerate. Best of luck.

jamespond24

iTrader: (13)

After the ground installation I toke the car for a drive and it still buck,hestiate at sometime lower rpm but most it happen at 3k rpm. Now it wouldn't start at all, I smell fuel out the exhaust and engine bay. The fuel filter was recently change during the rebuilt so I guess it doesn't hurt to do it again. As for fuel pressure I haven't check it yet.

jamespond24

iTrader: (13)

Also suddenly the damn fuel pump goes on and stays on when ignition is turned ON. Bad fuel pump relay?

Dustinali

iTrader: (10)

The car used to have a haltech in it and jamespond24 is putting it back to stock. The 12v on both poles was an error james did not unhook the primaries and miss understood me when I was telling him to check them. So the car only has 12v to one side. Also James can ohm out the injectors from the ecu plug and see them all fine. The car idles fine when the maf is unplugged and dies when it is plugged in. The engine harness, MAF, ecu, and boost sensor are from my S5 TII and it worked great. I don't see the maf going bad like that. Also the fuel pump I am thinking is staying on for other reasons. I believe the pump is controlled by the computer and whoever had the haltech must have rewired the pump for operation. Any help for james would be greatly appreciated. He is a great guy and I am 6 states away and can't think of what else to check.

Dustin

jamespond24

iTrader: (13)

Thanks Dustinali for your help. After the grounding install I stated the car and drive it to see if the hestitation is still there and it is at 3k rpm. Now the funny thing is that the car would start and 2 second later died regardless of whatever. When I unplug the afm it would start and hold idle ar 900 rpm boost gauge read vaccum at 17 but when plugged the afm and it just die. So I was wondering what could this be? The only thing I didn't check is fuel pressure ( going to over the weekend). Could this be a fuel pump relay,ecu, or afm? Remember this happen after a grounding job.

HAILERS

First try jumpering the fuel pump check connector in the engine bay, and with the AFM plug connected........try again.

jamespond24

iTrader: (13)

Ok, I'll post the results over the weekend.

jamespond24

iTrader: (13)

I did jump the fuel pump check connector and I didn't get fuel going to the rail. I even take the injectors out after jumping it but no fuel all I hear is the fuel relay clicking.

HAILERS

Sometimes the fuel hoses get swapped around where you connect them to the engine. Maybe swap them around and see what happens? Unless this engine has run before with the lines as they are, then that won't make much sense.

jamespond24

iTrader: (13)

The car ran and idle fine but it bogged at 3k rpm under boost. I was told the 3k bogging could be grounding so I installed new grounding. After the grounding I toke the car for a test drive and notice that it still bogged at 3k rpm. A few hour later I started the car and it runs like a blown motor and flooded the motor. Now with the afm it would start and 2 second later died regardless. I unplug the afm and the car start and idle fine with 17 at vaccum. I'm going to swap ecu,afm, and fuel pump relay Sunday. Hope one of those things are bad?

wthdidusay82

iTrader: (15)

I had the same problem with the 3800 rpm hesitation on my n/a along with backfiring under deceleration and downshifting , i cleaned all the grounds and nothing fixed it then I swapped on another tps that i had a spare of and it fixed the problem with the hesitation but the problem with backfiring is still there.

I am planning on getting a good used tps and getting a multimeter to adjust it , i wouldnt rule the tps out as being part of the problem if you still have hestitation issues or backfiring under decel/downshift issues.

If the car is not running now i would check for major vaccum leaks and check that the afm/maf is hooked up good and the connection is not loose, because if the afm isnt working this would cause the car to not run (obviously)

arghx

iTrader: (3)

you said it's running rich--is the thermosensor ok?