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truck runs for 30 sec then dies. i have the 7747 pcm.tried oil pressure switch didnt work. but i dont have a hot fuel mod. injectors spray on start up then just stop. check all my grounds and double checked wiring. could the hot fuel mod be causing this problem? i am also running my stock 2.5l fuel pump relay that has gray for the fuel pump test that is ran to b2 fuel pump in put
It's not the oil pressure switch, it is redundant and you don't even need it.
But if oil pressure switch is bad it will not continue to provide power to fuel pump relay if fuel pump relay fails. Check the relay and see if the power to fuel pump stops at same time?
There's a green wire to the relay that comes from the ECM that turns it on. But power comes from elsewhere, goes through relay when turned on by green wire from ECM and sends power to fuel pump.
Relay is on firewall and looks like picture below, wiring is simalar but differant relay.
HTH!
yes the green wire goes out before the it dies
If you hook 12 volt power up to the test/prime terminal and it runs? Then it would have to be the ECM? If wiring is correct. Is it consistent 30 seconds each time? Will it start after the stall?
Here's a link to diagram.
http://www.gearhead-efi.com/Fuel-Inj...8&d=1331599730
Do you have one of these on your harness?
yes its a consistant 30 sec and will fire after stall. no i dont have that.
puting a constant power to the test wire doesnt help motor still runs for 30 sec then dies. does anyone know what the fuel mod does. im going to go over the wire harness to night and make sure all wires and hooked up correctly and none of them are pinched.
What fuel mod? The Fuel module that came on some HD trucks? It runs the fuel pump for 20 seconds after key off.
I think you have some wires wrong and it's tripping the relay? Or wrong relay? You said it was from a 2.5L?
yes fuel pump relay are off the 2.5 tbi the wiring diagram has a hot fuel mod that i dont have. the fuel pump is tripping ill try puting the 350 relay on too
Might have lost the B2 signal when removing the Fuel module? Something is wrong with wiring?
does this computor need a knock sensor? mine is not hooked up
It will run fine without.
injectors are not palsing
i get 2 or 3 sprays of the injectors then motor fires and injectors stop and motor dies
Check pins D14 and D16 on the 7747. After initial fire, the 7747 takes over firing the injectors. If D14 and D16 are not changing state, then you need a new 7747. If they do change state, you need to check wiring from 7747 to injectors.
You've got some strange issues going on? What is this vehicle, transplant, hybrid, swap ? Need to double check wiring, there are power wires that are on all the time and others for Key On only, the Key On only need power from key on to crank and back to key on uninterupted.
If something is really wrong with wiring it could be a fried ECM now?
What Jim said about injectors, plus they get there power from positive source and the ECM is a ground for pulsing them.
Take a look at diagrams:
http://www.gearhead-efi.com/Fuel-Inj...Information-42
the pcm is good put it in another truck and it ran fine. i have a 92 s10 that had a 2.5l. we tried jumping power to the pur/wihite and no injector spray
YOU HAVE WIRING ISSUES!!!! until you resolve those issues your truck will never run!!!! D14 and D16 are grounded, not powered. also the ECM requires DRP, no DRP no run. FIX your wiring!!!!
i am trying to fix the wiring a.point in the right direction would be nice i have gone throgh it alk and cant find any problems
http://i80.photobucket.com/albums/j1...ps9cd680c9.jpg
what is this out of 92 s10 unplug it and i have no injectors
I told you exactly where to look. Are you listening? I will try again. After the truck fires initially, the ECM takes over firing the injectors. If it starts, that part is working correctly. The ECM requires a DRP to fire the injectors, no DRP no fire. Check that first. If you have DRP and a known good ECM, then you do not have continuity between the ECM and the injectors. It's that simple.
what us drp
That is the DRAC (Digatal Ratio Adapter Converter). If you uplug that and truck won't run you have wiring issues. All it does is convert the VSS signal for Speedometer, Cruise Control and ABS. It does have power and ground, neither should interfer with truck running.Quote:
Originally Posted by lilhupper
Distributor Reference Pulse.Quote:
Originally Posted by lilhupper
You tested the ECM in another truck and it's fine right? Now you need to trace each wire for correct location, start with link above to diagrams, couple are voltage checks, print them and USE THEM FIRST! Something is wrong with Batt Power or Ignition Power. What did you do to give the Jeep, (looks like a jeep in photo) power for Ignition On power for EFI system? SHould have used the old points power wire to trigger a relay to supply EFI system with Ignition On Power.
Rule of thumb for stock wiring.
Red is supply power.
Orange is always on batt power
Pink is Ignition On Power.
haveing all the sensor grounds hooked to gether will that cause an interferance? how about the chassie grounds?
Distributor reference pulse. Input to ECM at pins B3 and B5 one is reference high and one is reference low. This allows the ECM to determine engine RPM and see that the vehicle is running. above about 499 rpm, it says okay, I am running now.
ihave been following those diagrams from the beginning and there are 4 injector control wires are they suppose the be connected?
Yes, each injector will have 2 wires connected to it. Attachment 4182
The red and white wires go to one side of each injector, the other side goes from the injector to the ecm.
were does the tech wire go
You mean the tach as in tachometer? There's an extra white wire coming off the gray plug on coil for tach wire.
yes and it goes to the white on the distributor
got it running thaks for your help
Nope, wrong one...
were does it go one side goes to tach were is the other? if i put it to the est wire it runs great
Attachment 4185
The tach wire goes from the tach in the dash to the coil. The est wire should be hooked up as shown. You do not need the tach wire connected for the truck to run. Most trucks didn't come with a tach.
ok new questions iplug in the ignore mod bypass and truck dies. when un plugged at full throttle it starts loading up
truck runs good with the bypass wire unplugged when plugged in it retards the timing off the scale. could it be because i dont have a esc mod hooked up?
You never answered this? I have no idea what motor this system is on? Only clue I have is a picture that looks like a Jeep, no engine?Quote:
Originally Posted by EagleMark
I have run these systems with no ESC or knock sensor and timing works fine.
What distributor? What engine? Pugging in the bypass wire and having timing go backwards happens a lot in reverse rotation distributors and DurSpark conversion, the 2 wires from pickup coil need to be reversed.
its a 75 vet motor lunati voodoo cam #10120701LK 487x head holley street dominator intake distributor RPT #GM04 its goin in a 92 s10
Back to a wiring issue, bad EST/ICM in distributor or... should not be wrong.... the wires on pickup coil in distributor are crossed.
That's going to be a lot of fun to drive when tuned! :thumbsup:
yeah if i can get it running right. if the pick up wires are crossed could it wreck the EST? btw thanks for all the help this is my first engine swap.
and i found a problem on one of those working diagrams. for the est mod the pigtail goes a.b.c.d on the diagram it goes a.b.d.c
No, I've had them brought over to shop cause they don't run, swaped wires and they ran fine. Not saying this is your issue!Quote:
Originally Posted by lilhupper
Which one?Quote:
Originally Posted by lilhupper