rx7fcfc

iTrader: (1)

i have a 86 fc. the mods that were done to it are b4 i got it are
-all emissions removed
-aftermarket intake

the problems it had when i first got it were
-it would die when acceleratingor at idle: i fixed it by cleaning out the fuel tank and the rest of the fuel system from rust

the problem im still having is that if i accelerate too fast the rpms will get stuck at 4k but when i accelerate slow it will go all the way up to redline

the things i have done to try to fix it are
-changed the ecu
-change the fuel pump
-changed injectors
-check some vacuums
-checked the crank angle sensor

well heres the video of what happening thanks for watching guys i know my idle is kinda high i fixed it after the video was taken


http://www.youtube.com/watch?v=zQ7Tnh5z6RQ

satch

iTrader: (1)

To start with disconnect the hose to the boost/pressure sensor and plug the hose and then disconnect the TPS to simulate load and try it again. If this doesn't help it looks like the secondary injectors are having a problem turning on perhaps and this could be a function of poor grounding.

You could also with the help of and LED light tell whether the secondaries are kicking in properly. First get a voltage reading from pins 3H and 3F w/key to on as they both should read 12 volts w/key to on. Then take the LED and place the negative wire to the LED to pin 3H and the other wire of the LED to pin 3I and rev the engine with procedure mentioned above- hose removed,plugged and TPS disconnected and see if the LED light flashes repeatedly when the 3800 rpm level is hit. Do the same for pin 3F. If it does that means the secondary injector is coming on.

rx7fcfc

iTrader: (1)

thank for the response what ground would be responsible for the injectors? and where would it be located the reason i ask is because the previous owner redid all the grounds so there not where there supposed to be

SirCygnus

iTrader: (1)

its the TPS.

rx7fcfc

iTrader: (1)

thanks for the response could it also maybe be the ecu ground?

satch

iTrader: (1)

There's no specific engine ground responsible for the injectors other than the main engine ground on top of the UIM. Pin 3A Black wire, 3G Black wire, 2R Brown wire and 2C Black wire at the ECU could be regrounded. Remove the plugs to these wires after disconnecting the negative cable to the battery then remove a half inch or so of the protective sheath to the wire then solder a wire to each and then ground the other ends to the bolt that locks the ECU in place (two to choose from at the front of the ECU).

satch

iTrader: (1)

I believe he was joking with the TPS comment. The TPS should not have any bearing above 3000 rpm or so. With the car running press down on the throttle linkage by the TPS and when it pulls away from the rod extending out of the TPS have someone in the car to check what the rpm level is at that point in time and that will tell you when the TPS is no longer becomes a player.

paulin

hey, I noticed your water temperature gauge is higher than it should be. It should be reading at about 1/4 of the way up the gauge. Where it is now will not break the car, but don't drive to long if it goes any higher. You might wanna look into why your temp is so high. Btw I'am new to this but my temp gauge sits about the same and I think its my thermostat being stuck open. Are you using a thermostat?

rx7fcfc

iTrader: (1)

so do i replace my injector if there not turning on or could it be a wiring problem?

satch

iTrader: (1)

It would be an electrical problem related to the wiring or ECU. The test I provided you with checks the electrical side of things. Even if the injector was completely clogged the ECU would still try to fire it when it was supposed to.

rx7fcfc

iTrader: (1)

thank man i really apreciated

rx7fcfc

iTrader: (1)

does anyone have a link as too how to reground your ecu?

rx7fcfc

iTrader: (1)

can it also be that my 5th and 6th ports are not opening?

Sch1Tz0

Follow the steps Satch has laid out... he is definitely the one you want helping troubleshoot the electrical. It's a matter of elimination to find out and he gave you the 1st step...

satch

iTrader: (1)

There are 4 grounds on th ECU. Pins 3A, 3G, and 2C are Black wires and pin 2R is a Brown wire. Disconnect the negative battery terminal. Disconnect the 2 plugs necessary ( smallest two in size). Pick the first wire to work on and cut a slit all the way around the wire at a point 2 inches or so behind the back of the plug. Pull away the plastic covering of the wire with thumbnail to expose about half an inch or so (1/2 to 3/4 inch). Solder the additional ground wire to the existing ground making sure you heat the 2 wires with the soldering gun to where it gets hot enough that the solder melts onto the wire when touched. Do the same for the other 3 wires. Use the front 2 ECU mounting bolts to connect the other end of the new ground wire perhaps using some dielectric grease and then tape up the soldered area and reconnect the battery.

rx7fcfc

iTrader: (1)

thanks man you really know your stuff

satch

iTrader: (1)

99% of whatever I know comes from reading the posts, old and new. The advanced search function will tell you everything you need to know in triplicate. If you want to figure something out related to electrical problems for example, then include the name HAILERS in the search and you will find an abundance of info available. I'm just basically regurgitating his and other info provided by other posters. I've regrounded the ECU myself so this info actually comes from both reading and personal experience.

rx7fcfc

iTrader: (1)

so i checked the secondary injector and the were bad so i replaced them now the car runs good thanks guys for the help