skirkland1980 Posted January 21, 2014 Share Posted January 21, 2014 I was making some dyno pulls on the 83 280zx turbo when the car died and hydro locked with fuel. It was running really well before this happened. I'm using the Bosch injectors found on Ford cfi engines. Static fuel pressure is 30 psi and multiplies with boost @ 25 psi. Anyone have an idea what happened to my injectors? Thanks Quote Link to comment Share on other sites More sharing options...
seattlejester Posted January 21, 2014 Share Posted January 21, 2014 What is the duty cycle on the injectors? Only thing I can think of is that they locked open. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 21, 2014 Author Share Posted January 21, 2014 I don't know what the duty cycle is but I do think I am likely pushing the limits of these injectors. That is a good point you make about them being stuck open. Maybe a gentle tap with a screwdriver handle will unstick them? Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 22, 2014 Share Posted January 22, 2014 It's more likely that something went wrong in the injector control circuitry. holding an injector or two or all open. The injector's default condition is closed (spring), so unless you got some crap through the fuel filter and the injector filter, there's no reason for them to stick open. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted January 23, 2014 Share Posted January 23, 2014 I wasn't thinking permanently stuck, I was thinking sticking open during running. If you were on the high side of the duty cycle, it could happen, but if you aren't pushing the injectors very hard it is unlikely. If the engine flooded, either the fuel injectors dumped excess fuel, or the ignition source faltered. The injectors stayed open too long from being pushed in the duty cycle, or something went wonky with the internals. Is the car running at all right now? What happens if you turn the fuel pump on, do any of the injectors just spray fuel? Were they new injectors? How do you know it was hydrolocked with fuel? If the ignition source faltered, you would have to find out if it was the coil, distributor, spark plug, or spark plug wire. If spark stopped being supplied you could potentially flood the motor a bit, although I would imagine the fuel would eventually make it out either by running down the side of the cylinder or exiting into the exhaust manifold or something of that nature. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 23, 2014 Author Share Posted January 23, 2014 I only have answers to a few of your questions because it's been too cold to pull the fuel rail for inspection. I know t the engine hydrolocked because the starter just clicked. When I pulled all the plugs and soon the engine over fuel sprayed out in a 10 foot stream across the shop from at least 2 cylinders. I really need to get it apart and see what happened. Was just curious if this had happened to someone before and could either say yeah your injectors are fubar or not. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 24, 2014 Share Posted January 24, 2014 Take a battery and see if the injectors click. Take a meter and see if one side of the injector circuit, at the plug, is shorted to ground. Might tell you something. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted January 24, 2014 Share Posted January 24, 2014 Oh wow, that is quite a lot of fuel, yea, please don't crank that over. That can be an accident waiting to happen. Were these new injectors? Where were they from? I know there have been some knockoff injectors sold under the bosch name as OEM replacements from certain aftermarket stores. I agree, if possible test the injectors off the car. With ignition disabled. Me thinks you may find one or two of them on constant on. If it was enough to shoot out of the plug holes, you have quite a lot of fluid in there. This is all with the assumption this is gas, I really don't mean to insult you, but there is no chance this is coolant or water correct? I mean the last time I have seen fuel spray out of the sparkplug hole is with a flooded carb where the floats sank, but far more often, I have seen and heard of internally blown headgaskets flooding coolant into the chambers. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 24, 2014 Author Share Posted January 24, 2014 Yeah it's fuel. The injectors were remanufactured from motorman. Quote Link to comment Share on other sites More sharing options...
roger280zx Posted January 24, 2014 Share Posted January 24, 2014 I know a very good injector guy here in GA. He cleaned flowed and installed new baskets in my bosche's recently. I'm sure he could help you diagnose them. LMK if you want his contact info. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 24, 2014 Author Share Posted January 24, 2014 Yes please. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted January 24, 2014 Share Posted January 24, 2014 Yea, it sounds like you are familiar with everything so it is hard to help out. I guess to answer your question, yes I have heard of sticky injectors flooding motors, it could very well be the return spring or some fluctuating voltage or something of that nature. Even when injectors are remanufactured, they still don't inspect the internals, just a flow test and a rebuild with o-rings, maybe the filter screen is replaced to my understanding. A bench test should be pretty revealing when it warms up enough to try it. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 27, 2014 Author Share Posted January 27, 2014 I pulled the injectors and rail off as an assembly and pressurized the rail. The injectors didn't leak. I checked power and ground to the injectors, didn't see anything odd. Just an update... Quote Link to comment Share on other sites More sharing options...
loy Posted January 28, 2014 Share Posted January 28, 2014 If you suspect the megasquirt, http://www.diyautotune.com/tech_articles/megasquirt_injector_driver_troubleshooting.htm will help you narrow it down. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted January 28, 2014 Share Posted January 28, 2014 Hmm did you test the continuity from the pigtails to the megasquirt injector input? Unless your tune has a point where you are nearing max duty cycle, it shouldn't be flooding the motor. Unless your spark is failing for some reason. High or low impedence injectors? Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 28, 2014 Author Share Posted January 28, 2014 Thanks for that link loy. I will try to trouble shoot my ms. Only other thing I didn't think of was to ohm my injectors, they are low impedance. I hope it is the injectors though I think it may be time to upgrade. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 30, 2014 Share Posted January 30, 2014 Just FWIW, I'm 99.999% sure that a 440cc injector can't physically flow enough fuel to hydro-lock a running engine. To me this would suggest looking for faults that would cause an injector or injectors to be open when the engine is _not_ rotating. Sounds like you were already going down that path, just hadn't seen this explicitly pointed out. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 31, 2014 Author Share Posted January 31, 2014 The engine backfired and died. When it backfired that is when the fuel started dumping into the cylinders. It was about a minute before I tried to crank the engine. It made about one revolution and stopped. So no I don't think it hydrolocked while it was running. That has happened to me before and it just bent the rod and kept running. Quote Link to comment Share on other sites More sharing options...
loy Posted January 31, 2014 Share Posted January 31, 2014 You can also check the injector outputs in tuner studio. Go to Advance then output test mode. It can be finicky but works. What are you using to trigger the megasquirt? Is the megasquirt reading RPM fine? Possibly something to look into also.if the case. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted February 14, 2014 Share Posted February 14, 2014 Hydrolocked and turning it over would result in a broken motor. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.