New rebuild ran for 35 minutes
Sorry about that, they are 720s.
Joined: Sep 2005
Posts: 25,581
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From: Smiths Falls.(near Ottawa!.Mapquest IT!)
check your Injector wiring to make sure that the primary wires are indeed hooked up to the primary injectors.
I made the mistake of switching wiring and it stumped me for weeks.It would start and die..stumble and if you give it gas it would run a bit then backfire.
I made the mistake of switching wiring and it stumped me for weeks.It would start and die..stumble and if you give it gas it would run a bit then backfire.
If that's not the problem, I'm going to remove the primary injectors and send them out to get cleaned.
The secondary injectors are not used for starting or idling so switch your primaries for the secondaries before spending money on an unknown. I seem to remember you stating they were all 750cc injectors so switching them should create no problem as it relates to starting and idling, but you need to tone down the idle speed to a more acceptable range.
And in fact you could just switch the ECU pins for the injectors as opposed to physically switching them. Switch 3W and 3X w/each other and do the same for 3Z (LG/Red) and 3Y (LG/Black).
I'd planned on shipping the injectors out so I already have the UIM off. I'll switch them around tomorrow. I'll post back and let you know what happens.
My money's on clogged injectors due to bad/wrong fuel.
It's easy to over-diagnose a problem, when a lot of times it's something simple or a problem had a simple cause. Been down that road before. I say this with utmost respect for the opinions given. Some of the causes given don't jive with the car having ran for 35min. and then having problems.
Remember, OP, as you switch injectors - if you used the secondary injectors when the engine ran (i.e. took it for a drive where they came on such as over 3800 RPM under load), they may be clogged too.
It's easy to over-diagnose a problem, when a lot of times it's something simple or a problem had a simple cause. Been down that road before. I say this with utmost respect for the opinions given. Some of the causes given don't jive with the car having ran for 35min. and then having problems.
Remember, OP, as you switch injectors - if you used the secondary injectors when the engine ran (i.e. took it for a drive where they came on such as over 3800 RPM under load), they may be clogged too.
You mentioned a new fuel pump... Is it possible that you rolled the o-ring on the pump when you installed it?
I've seen this problem on a 90 TII after a pump change. You turn the key, the pump builds enough pressure to start the car, but not enough to keep it running. The o-ring on the pump pushed its way down and started leaking fuel in the tank. The fact that the bleed down pressure is so low is suspicious.
I've seen this problem on a 90 TII after a pump change. You turn the key, the pump builds enough pressure to start the car, but not enough to keep it running. The o-ring on the pump pushed its way down and started leaking fuel in the tank. The fact that the bleed down pressure is so low is suspicious.
My Tii sat for over a year before i bought it and it ran like **** and could barely hold an idle on its own. Turns out the body of the AFM was leaking at the two seams and all of the air bleed socket orings were absolutely rock hard. After replacing them it has ran great since(well till the fuel pump took a dump).
We sent all four injector out to WitchHunter. They should be back soon.
thanks for the help guys
ash
When you hit the accelerator, the ecu senses the rate of change of the tps (how fast it's opening). On old carbureted cars there was a piston inside the carb that squirted a little extra stream of fuel in the intake as the throttle moved open. It only injected fuel if the throttle plate moved. It's called the accelerator pump. It keeps the engine from dying upon a sudden rush of air. The ecu mimics this by sensing the tps rate of change, thus enrichening the mixture.
It sounds to me as if the pumping action is keeping it from a lean condition.
You can try using a multimeter and the chart in the fuel/emissions section of the FSM. There's an ecu pin out diagram as well. The chart will tell you typical voltage values at each pin. Do this with the ecu and all sensors plugged in. You can leave the injectors out for this test, just make sure the AFM flapper doesn't move when you turn the key on. Otherwise it will spray you with fuel.
It sounds to me as if the pumping action is keeping it from a lean condition.
You can try using a multimeter and the chart in the fuel/emissions section of the FSM. There's an ecu pin out diagram as well. The chart will tell you typical voltage values at each pin. Do this with the ecu and all sensors plugged in. You can leave the injectors out for this test, just make sure the AFM flapper doesn't move when you turn the key on. Otherwise it will spray you with fuel.
The injectors came back yesterday and I got it all put back together today.
However, the injectors were not the problem, which I knew as soon as I saw the injector report. The injectors just didn't need cleaned at all.
The engine is not firing now. I didn't pull the plugs out yet to check for spark but it sure doesn't sound like it is even firing. Doesn't even try to start.
However, the injectors were not the problem, which I knew as soon as I saw the injector report. The injectors just didn't need cleaned at all.
The engine is not firing now. I didn't pull the plugs out yet to check for spark but it sure doesn't sound like it is even firing. Doesn't even try to start.
Well, start with the basics. Compression, spark, fuel. I assume by now that you know what a flooded engine sounds like. If all that checks, look for an air leak between the AFM and throttle.
But seriously, my above post about testing at the ecu for voltages is the only way to diagnose a poor running (computer-controlled) engine. Unless you want to keep spending superfluous amounts of money by replacing random parts based on a guess... by someone who hasn't seen the car.
But seriously, my above post about testing at the ecu for voltages is the only way to diagnose a poor running (computer-controlled) engine. Unless you want to keep spending superfluous amounts of money by replacing random parts based on a guess... by someone who hasn't seen the car.
Well, start with the basics. Compression, spark, fuel. I assume by now that you know what a flooded engine sounds like. If all that checks, look for an air leak between the AFM and throttle.
But seriously, my above post about testing at the ecu for voltages is the only way to diagnose a poor running (computer-controlled) engine. Unless you want to keep spending superfluous amounts of money by replacing random parts based on a guess... by someone who hasn't seen the car.
But seriously, my above post about testing at the ecu for voltages is the only way to diagnose a poor running (computer-controlled) engine. Unless you want to keep spending superfluous amounts of money by replacing random parts based on a guess... by someone who hasn't seen the car.
I pulled the plugs and none of the plugs are getting spark. Once I get the spark back, I'll double check for air leaks.
Hi guys,
Its been a while since I worked on my 7. Right after Thanksgiving I rolled my Mustang. I was going around a bend towards the right and a deer was standing right in my lane. I veered to miss the deer, slid on some wet leaves, lost control, hit a bank and rolled the Mustang. I hit my head on the side window and ended up in the hospital with a concussion and 20 stitches on my head. A salvage yard now owns the Mustang. But, I'm good now.
The not firing issue was the fuse in the cabin. It fires now but won't start. Its not flooded.
I did notice that the main wiring harness was almost touching the turbo. I think my next step should be to unwrap the harness and check for burnt wires. Maybe 35 minutes was enough to melt through a wire or wires. Just taking a quick glance at the harness didn't reveal any problems
Its been a while since I worked on my 7. Right after Thanksgiving I rolled my Mustang. I was going around a bend towards the right and a deer was standing right in my lane. I veered to miss the deer, slid on some wet leaves, lost control, hit a bank and rolled the Mustang. I hit my head on the side window and ended up in the hospital with a concussion and 20 stitches on my head. A salvage yard now owns the Mustang. But, I'm good now.
The not firing issue was the fuse in the cabin. It fires now but won't start. Its not flooded.
I did notice that the main wiring harness was almost touching the turbo. I think my next step should be to unwrap the harness and check for burnt wires. Maybe 35 minutes was enough to melt through a wire or wires. Just taking a quick glance at the harness didn't reveal any problems
I have an Xterra now but I am looking forward to getting the 7 running again.


