QuestionQUESTION: Ordered the proper pressure tester and fitting, tested BEFORE fuel rail and got 32 psi & 40 psi (minus vacuum). We tested after the regulator and found maybe 1 psi. Is that an indication of a bad regulator? If I want to test the compression i'll have to buy an adaptor... or have I found my problem?
ANSWER: Hi Adam,
The pressure test is correct (the fuel after the regulator is dumped fuel going back to the tank so you should not see much of any pressure there) however you need to know if you have that pressure 32/40 at the time it fails.
All gas engines only require 3 items to run, Compression, Fire and Fuel. If an engine dies, one or more of the 3 has gone away. If it starts up later and runs again then it is unlikely compression as when compression goes away it usually doesn't return so you can put that aside for now. That leaves only 2.
You have done the preliminary test of fuel pressure but you must see the pressure at either the failed moment or in the failed condition (no start) But keep in mind that you are only testing fuel supply to the injection system. It does not mean that the injection system is operating at the time of failure. ALL TESTS MUST BE DONE IN THE FAILED MODE!!!
It is easy to test for Fuel or Fire if the engine dies and won't start. Just spray a little starting fluid into the intake and if it fires up for a second or two, it is a Fuel problem.
If it don't fire up remove a spark plug wire and put a known good spark plug on the wire and lay it on a metal part of the engine and spin the starter and watch for a thick blue spark.
If the spray starter fluid did make it start for a second or two, get a Noid light from most any auto parts store. (Lucas or Bosch connector) They are not expensive and you plug the noid light into an injector wire plug and spin the engine and watch for the flash. If no flash, test each of the two wires for power (key on) If no power get a wiring diagram and start testing from the wire back to the source. If you do have power then you need a wiring diagram to start testing for power at the ECU, several grounds on the ECU and ignition pulse signal at the ECU.
If you don't have a diagram let me know and I will put one up on my web site for you to copy.
Howard
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QUESTION: ALL TESTS IN FAULT MODE
Spray test: Successful (2 secs, then dies)
-note: fuel pressure drops to 20 psi during 2-3 seconds it will run
Spark test : orange spark (cranking)
Niod test: Successful (dim,pulsing: cranking)
My dad thinks it may be the timing chain, does that make sense?
I would certainly be in need of a diagram, I am at a loss; you have already saved me $100's in guessing. Thank you so much for your help.
ANSWER: Adam, While an orange color spark is not considered good, it fired off with spray. You originally said you had 32/40 PSI fuel pressure, now you say 20 during a 2-3 sec run????
Put the fuel pressure gauge on just before the fuel rail and turn the key on and open the airflow meter flap and hold it open for a minute or so and watch the gauge. The pressure should read about 42 PSI or close to it and it should stay there for as long as you hold the flap open. If it does not do that check the fuel filter and then the pump.
A broken timing chain will totally disable an engine but can in no way lower fuel pressure. If an engine does not start and you spray a fuel into the intake and it fires up for a second or two then you have found the problem which IS fuel. And if you see 20 PSI fuel pressure You for sure have a fuel supply problem. So fix it before looking for other problems.
Howard
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QUESTION: Howard,
I apologize for my answers being a little misleading, I think a lot faster than I type. I'm just frustrated with the car and excited to talk with someone who has the knowledge you have all at once.
The 32/40 psi reading was read at key forward, flap open. After spraying fluid into intake, the car will start momentarily.. reading 20 psi before cutting out.
plugs are brand new showing orange spark
AnswerOK, the 20 PSI is useless info as when the engine dies the flap in the airflow meter closes and that turns the pump off. The 20 PSI is just left over pressure that has not bled back into the tank.
The fact that it starts on the spray and that it has fuel pressure proves that the injection system is not operating. The orange color of the spark would be a indication of a weak spark but if it is in bright light that may be normal.
It is time to start testing the injection system and one more item. Has this car been out of service for some time? If so charge the battery and get a good jumper battery also and after you charge the battery in the car (even if it seems charged) connect up the jumper battery as though you are jumping off a car with a dead battery. Then try to start it with the two batteries (which are connected in parallel. If it starts up, go purchase a new "Deep Charge" battery for the car.
A "Deep Charge" battery is a Diesel or Marine battery.
If this car has been running and in service you are now going to have to start testing the injection system. You will need a wiring diagram of the injection system and if you don't have one let me know and I will put one on my web site for you to copy. You will need a 12v test light and a volt meter. Let me know when you are ready to start.
Howard
