Hi,
my car does not start (cranks only) after I clean the fuel injector and intake manifold.
so I check the spark with tester and it is fine.
then I check the fuel pressue with tester and the pressure shoots to over 42 psi without starting (normal between 38 and 46 psi) and slowly drops to 10 psi. I install fuel injector (FI) with new o-ring and gasket and there is no leakage aroung them. the fuel pressure regulator is ok. I got one from junk yard and the test show the same.
I notice there is some gas inside TB and only way to leak the gas is the FI body vavle. I took all FI out and notice #2 and #3 are wet on the FI nozzle tip and use small syring to push air through and can see some fluid coming out from the nozzle tip.
I thought I clean it well and do not know if this can be fixed by more cleaning. the resistance is all the same at 12.6 ohms under room temp at night in north CA
The fuel injector cleaning or just the removal and re-install may have somehow damaged the injector’s pintles . I think what a mechanic might do at this point is remove the injectors and pressurize the fuel rail and use a gadget to pulse each of the injectors and inspect the spray pattern. And verify they don’t leak when not being pulsed. At least that’s what I’d do – the equivalent of that actually – with my older VW Rabbit with its CIS k-jetronic fuel injection system when I had this problem.
I’m not sure what you mean by the fuel pressure slowly drops to 10 psi. You mean you crank the engine & it goes to 42, then after you stop cranking it goes to 10? How long does it take to make this drop? If it happens within a few minutes, it shouldn’t do that. Most likely either a problematic pump check valve allowing fuel to go back into the tank, or a leaky injector, leaking fuel pressure regulator, or just a leaky connection. You just have to go through and test each of those possibilities one by one. The gas has to be going somewhere, isn’t disappearing into mid-air … lol …
One idea you might try as a flyer … when doing this kind of work sometimes you inadvertently flood the engine with gasoline as part of the job, or subsequent testing. A flooded engine will crank and crank and never start, all the while showing no obvious reasons why not. Suggest to remove the spark plugs, shut off the fuel pump temporarily, and crank the engine several times. This should expel much of the gasoline in the cylinders. Then let the car sit a day or two with the spark plugs removed. The remaining gasoline will evaporate. The engine might well crank and start fine after that. Best of luck.
Thanks George.
I found the root cause for the no-start. The injector valve body itself (not external from o-ring) was leaking and I have to get 4 used one from pick-n-pull. the used ones test good and spray nicely. the fuel pressue head steady at around 40 psi when not running and 34 psi while running. I think it should be ok.
right now the car starts, but the engine shakes really bad. about 2 minutes the cel light is flashing and the code is p1399 (random misfire). I replace with new distributor, ngk iridium spark and prestotile spark wire. the spark tests ok and the wire order is right. the engine compression test is 180 for 1-3 cylinder and 190 for #4.
I do not think ignition timing may cause this. I tried my best to mark the position when I switch the new distributor. no smoke from exhaust for sure.
Any idea?
My Ford truck went from an easy to start state to a stubborn start after I rebuilt the carb. The problem turned out to be the new power valve was dripping gasoline into the intake manifold when the engine was off. So I’m with you on the leaking fuel component floods the engine idea being a likely cause of cranks ok but hard to start. After I replaced the defective power valve, it returned to r-pop-run … i.e. now with the power valve problem fixed it doesn’t even get to the second r in rrrrrr before it pops & starts up, purring & ready to go … lol …
Good for you, it sounds like you’ve solved the leaky injector problem and have a consistent fuel pressure. 34 psi seems maybe a little low though for a Honda, maybe double check that to make certain. A lower fuel pressure could certainly cause poor running, but I’d guess 34 psi would still be within the range where the computer could compensate for it once the engine warmed up and the O2 sensors came on-line. You might see a significant fuel trim though. If you have the capability, check to see what the fuel trim values are maybe.
You compression values seem ok, doubt that’s the problem. hmm … I’d guess either the ignition timing is running amok, or there’s still a problem with the spark. Double check the ignition timing with a timing light at idle. If that’s ok, replace the distributor cap and rotor. Still a no go? Replace the ignition module is probably next. Either that or find a shop who has the Toyota scan tool, lab o’scope, and other necessary equipment to properly diagnose this problem for you.
BTW, wayward valve timing could cause this. I doubt that’s the problem b/c your compression values look ok, but its possible to have ok compression with wayward valve timing. My Corolla has a timing belt so if I’m concerned about valve timing I can remove the upper timing cover to expose the cam sprocket and check the valve timing with a timing light. Not sure of your engine configuration whether this same method is possible for you though.
I replace the whole distributor and spark plug and the wire. I hope the base timing is not an issue. will continue to check and provide the result. thx