ZZ4 cutting off
#1
ZZ4 cutting off
I have a Sandrail that has an 02' ZZ4, Superram intake, Accel DFI. On last trip I started having issues with the engine cutting out.
As I roll on gas it would briefly cut off/stumble/miss, then back on. On other times, it would cut off all together until I let up on the gas pedal. Then it would be fine.
Next time I drove it, all was fine for a full day of duning.
Next ride, started intermittantly cutting out.
Seemed to happen mostly just off idle. Started to stumble at idle as well.
Changed fuel filter, no difference.
Thanks,
Wejaz28
As I roll on gas it would briefly cut off/stumble/miss, then back on. On other times, it would cut off all together until I let up on the gas pedal. Then it would be fine.
Next time I drove it, all was fine for a full day of duning.
Next ride, started intermittantly cutting out.
Seemed to happen mostly just off idle. Started to stumble at idle as well.
Changed fuel filter, no difference.
Thanks,
Wejaz28
#3
Moderator
iTrader: (3)
Re: ZZ4 cutting off
Could be a lot of things. Need more info. I'd start with making sure your ignition system, plugs, cap, wires are up to snuff. Then check your fuel pressure. Schraeder valve on the fuel rail, tape the gauge to the windshield and see what it's doing when you're driving.
The sheer number of things that could cause an off idle stumble is staggering, but make sure the basics are working, then make sure you're getting fuel.
The sheer number of things that could cause an off idle stumble is staggering, but make sure the basics are working, then make sure you're getting fuel.
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#8
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Join Date: Dec 2011
Location: Pacoima CA
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Car: 92 camaro RS
Engine: zz4 craite engine with TPI set up
Transmission: T-5
Axle/Gears: 10 bolt 3.42 posi
Re: ZZ4 cutting off
I just want to be part of this conversation, I also have a zz4 with a stock 92 tpi system. The car will go a good run a few days and other days after 30-40 minutes of driving the car will start to struggle and turn off. I usually just wait a 5-10 minutes and the car will be like nothing happen. I already change the fuel pump, fuel pressure regulator, injectors, new spark plug wires. I'm going to try and replace the distributor module next.
#9
Sponsor
iTrader: (92)
Re: ZZ4 cutting off
Sounds like a possiable ecm. Bye turning off the key your resetting it.
Just a FYI it’s gm service number 1227730. I wouldn’t think the icm or pu coil would be bad . Because your not resetting anything in the distributor bye turning the key off and back on. You might be able to wrap on the ecm case while this is happening to see if it straightenes out or starts to act up.
Just a FYI it’s gm service number 1227730. I wouldn’t think the icm or pu coil would be bad . Because your not resetting anything in the distributor bye turning the key off and back on. You might be able to wrap on the ecm case while this is happening to see if it straightenes out or starts to act up.
#10
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iTrader: (92)
Re: ZZ4 cutting off
If your stating the engine runs good when it’s cold but is dying when warm. I would think it needs to be tuned. Or you cold use a adjustable fuel pressure regulator to increase fuel flow. I have tuned a tpi maf zz4 , 30#hr injectors worked great. Might have been overkill but after the injector constant was set in the tune I still had to add some fueling to get the blm (block learn mode) in order.
#11
Re: ZZ4 cutting off
Well, hooked up laptop and there was a stored code “23” right there on the dash screen. “Low TPS voltage” .
swapped it out, recalibrated and loaded new file. Cars runs fine, but this is an intermittent problem.
If it’s not fixed, suppose it could be whatever sends voltage to tps.
swapped it out, recalibrated and loaded new file. Cars runs fine, but this is an intermittent problem.
If it’s not fixed, suppose it could be whatever sends voltage to tps.
#15
Re: ZZ4 cutting off
If an injector was bad, wouldn't that injector cause one dead hole, other 7 still firing.
This problem manifests itself as a complete shut down if I continue to depress pedal until I let off and it comes back on it or a short cutoff if I stay right around the bottom of throttle and feather.
This problem manifests itself as a complete shut down if I continue to depress pedal until I let off and it comes back on it or a short cutoff if I stay right around the bottom of throttle and feather.
#16
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iTrader: (92)
Re: ZZ4 cutting off
Not sure if your dfi is batch or sequential l. Batch could shut down the injector driver if a coil is shorting. Sounds like your not running a multec style injector so it might not be that.
Wonder if you have a fuel pressure issue.
Wonder if you have a fuel pressure issue.
Last edited by Tuned Performance; 11-18-2017 at 07:13 PM.
#17
Re: ZZ4 cutting off
Not sure what "Batch" or "Sequel" mean.
Just installed a new Bosch 044 just because.
Car is running fine........In the trailer. Wont find out until Xmas trip..
Thanks,
Kevin
Just installed a new Bosch 044 just because.
Car is running fine........In the trailer. Wont find out until Xmas trip..
Thanks,
Kevin
#18
Re: ZZ4 cutting off
UPDATE:
Just got back from Glamis, what a terrible trip. Car starting cutting out on first trip, barely made it back. By morning would not even run without starting fluid being sprayed. Every once and a great while, car started and runs great for about 30 seconds, then it just shuts off, like a switch.
ECU is a Gen 7, 77040, Ver 3.1 10/02
What I do know:
I have spark and fuel is flowing out fuel rail under pressure when pump switched on. on rare occasion it ran, fuel pressure was 43, vacuum removed. Car will run on starting fluid. Did get another TPS Code. Could be byproduct of shutting off I guess.
*******It appears the injectors are not getting a pulse signal when it doesn't run.*******
Local Glamis repair shop guy said that when this system was more widely used, 90% of the time it was the distributor due to moisture. Took cap off and switched on, then cranked. Got a Red and Green light, one of them flashed when cranking(cant remember which). No idea if this indicates anything.
Parts replaced:
Fuel pump
Fuel filter
Checked all fuel lines(Not that old)
TPS (3 times) Set to .50v
Coil and Coil wire(same that was on it)
Replaced Acell 6 IGN box(Same that was on it)
Cap, rotor and wires fairly new
Re-grounded ECU and IGN box
Reprogrammed with multiple tunes (It does ask me if I want to re-calibrate or use current settings. Don't recall that before).
I've got a Distributor coming. will try that next....
Any Ideas?????? ECU>> I'm out of Ideas...
Thanks, Kevin
Just got back from Glamis, what a terrible trip. Car starting cutting out on first trip, barely made it back. By morning would not even run without starting fluid being sprayed. Every once and a great while, car started and runs great for about 30 seconds, then it just shuts off, like a switch.
ECU is a Gen 7, 77040, Ver 3.1 10/02
What I do know:
I have spark and fuel is flowing out fuel rail under pressure when pump switched on. on rare occasion it ran, fuel pressure was 43, vacuum removed. Car will run on starting fluid. Did get another TPS Code. Could be byproduct of shutting off I guess.
*******It appears the injectors are not getting a pulse signal when it doesn't run.*******
Local Glamis repair shop guy said that when this system was more widely used, 90% of the time it was the distributor due to moisture. Took cap off and switched on, then cranked. Got a Red and Green light, one of them flashed when cranking(cant remember which). No idea if this indicates anything.
Parts replaced:
Fuel pump
Fuel filter
Checked all fuel lines(Not that old)
TPS (3 times) Set to .50v
Coil and Coil wire(same that was on it)
Replaced Acell 6 IGN box(Same that was on it)
Cap, rotor and wires fairly new
Re-grounded ECU and IGN box
Reprogrammed with multiple tunes (It does ask me if I want to re-calibrate or use current settings. Don't recall that before).
I've got a Distributor coming. will try that next....
Any Ideas?????? ECU>> I'm out of Ideas...
Thanks, Kevin
#19
Member
iTrader: (2)
Re: ZZ4 cutting off
What did the datalogs show?
Youre getting a tps code most likely because it needs to be greater than .2v at idle. You may have to grind a slot in the switch in order to rotate it for a higher reading.
That’s a very old ECM, one of the first versions. But if it’s seeing an ignition signal then it should fire the injectors.
Do you have a noid light? If not grab one and connect it to the injectors when it acts up. That should tell you if it’s an internal wiring or ECM issue vs pressure or other.
Hope this helps.
Youre getting a tps code most likely because it needs to be greater than .2v at idle. You may have to grind a slot in the switch in order to rotate it for a higher reading.
That’s a very old ECM, one of the first versions. But if it’s seeing an ignition signal then it should fire the injectors.
Do you have a noid light? If not grab one and connect it to the injectors when it acts up. That should tell you if it’s an internal wiring or ECM issue vs pressure or other.
Hope this helps.
#20
Re: ZZ4 cutting off
The TPS is set to .5v. Fuel pressure remains Constant 43psi when cranking or during brief running moments. No pulse at noid light.
I have no logs as it’s not running. Frankly I haven’t ever tried to log it.
as stated above, it will run on starter fluid.
Kevin
as stated above, it will run on starter fluid.
Kevin
#21
Member
iTrader: (2)
Re: ZZ4 cutting off
I'm guessing .5 on the low side? Does it change consistently when you move the throttle? I'd still do a log as well. Set it up for, TPS, MAP, RPM, and O2 as the base parameters.
It's probably seeing an ignition signal because the pump is running. But just to be sure, while booted up with it on the dashboard, crank it and watch the rpm count in the middle of the screen. It should read 150rpm or so during cranking.
If it does then you most likely have either an ecm or wiring issue. It won't fire the injectors until it sees an ignition signal first. From there it'll energize the drivers for the injectors. If all of them aren't firing then I'd look at the ground coming out of the harness. You may want to check the inj plug at the main harness as well to confirm current and ground there too.
Again that's a very old box, 15 years, it may have breathed it's last breath.
Thanks.
It's probably seeing an ignition signal because the pump is running. But just to be sure, while booted up with it on the dashboard, crank it and watch the rpm count in the middle of the screen. It should read 150rpm or so during cranking.
If it does then you most likely have either an ecm or wiring issue. It won't fire the injectors until it sees an ignition signal first. From there it'll energize the drivers for the injectors. If all of them aren't firing then I'd look at the ground coming out of the harness. You may want to check the inj plug at the main harness as well to confirm current and ground there too.
Again that's a very old box, 15 years, it may have breathed it's last breath.
Thanks.
Last edited by efiguy; 01-03-2018 at 10:43 AM.
#22
Sponsor
iTrader: (92)
Re: ZZ4 cutting off
If you determine it’s the ecm you might be able to work a deal here.
https://www.thirdgen.org/forums/engi...accel-gen.html
https://www.thirdgen.org/forums/engi...accel-gen.html
#23
Re: ZZ4 cutting off
Found a ecm on Ebay, same year and version.
Is there any setup required or can I just plug it in my car and download my file into it through CAL Map?.
Is there any setup required or can I just plug it in my car and download my file into it through CAL Map?.
#27
Re: ZZ4 cutting off
Ok, so I went out to trailer to further diagnose car and wouldn't you know it, it ran perfect.
I did take a few logs of it running, but it wont let me upload them.
Kevin
I did take a few logs of it running, but it wont let me upload them.
Kevin
#47
Re: ZZ4 cutting off
I ve changed almost everything, as noted above.
Should I just replace the ECM and distributor or one at a time, or is there another avenue I should do?
Should I just replace the ECM and distributor or one at a time, or is there another avenue I should do?
#49
Re: ZZ4 cutting off
“Ok, so I went out to trailer to further diagnose car and wouldn't you know it, it ran perfect.”
it ran perfect the other day. That’s when I took the screen shots.
it ran perfect the other day. That’s when I took the screen shots.