CJNAZ

OK. Need to challenge your expertise with a 3.0 that won’t start.
New motor with 8000 miles on it. Ran strong. One morning it decided to not start. Cranks and cranks but won’t fire up. Have spark to plugs. Replaced cap & rotor to be sure. Some fuel too on plugs when pulled. Did an Ohm check on the cold-start injector. Reading was within parameters. Pulled fuel filter and it contained reddish colored fuel with debris. Replaced with new filter. Cranked motor for about 60 seconds and it started. Ran fine. Very strong. Timing was good. Within a week or so it started getting harder and harder to start. Assumed it was the fuel pump. Dropped tank. Inside of tank was shiny and clean. Replaced with a new fuel pump/strainer. Installed new sending unit while tank was out. Tried to start and nothing. At first attempt motor acted like it was going to fire right up. Did not start though. Cranked and cranked, nothing. I am stumped. I sincerely seek as much advice and steps of troubleshooting as you can possibly provide. I’m very mechanically inclined but this has got the best of me. Please HELP!!!
P.S. – I wish I could swap out to a better motor but this was rebuilt and can’t afford another change for awhile.


Thanks for your help,
Corey in Arizona

oldblue

are you sure you have spark to each plug?? use a spart tester tool, or man up and hold it while someone cranks. you sure you have fuel entering the engine?? spray a little starting fluid in the intake (a LITTLE spray, and AFTER the air flow meter, not through it!!) and see if it fires up for a second. these are the two most basic needs and two quickest tests to try. it would also be a good idea to pull codes. start here and report back.

combatcarl

As stated above, check spark and fuel. But my bet is going to lie in the fuel direction, as that's the last thing you messed with. Jumpering fuel pump terminal will tell you if it's even working, but there's a whole trouble shooting tree to follow. Find an FSM, try the link in my sig to find one.

CJNAZ

OK, I have spark. Before I spray starter fluid into the intake I thought I would mention what has happened. After I let the rig sit overnight I tried to start it. In the very beginning of the start process the motor tries to fire and run for a slpit second. Sounjds like it will start right up. Then it just goes back to turning over and over with no starting. Then I can smell fuel. I'll try the starter fluid. what is your opinion on the fact that it fires immediatly then ceases to fire?
Thanks for your help!

vasinvictor

iTrader: (3)

Pehaps your timing belt jumped a tooth or three? You should have a spring type tensioner, that Toyota later substituted for a hydraulic. Something to consider.

CJNAZ

Well, I am reluctant to think it it the timing belt. The motor ran strong, then all of the sudden wouldn't run. Replaced the fuel filter and it started and ran strong as an ox. Then faded into hard to start episodes finally ending in no start at all. Timing was checked while running. Dead on.

CJNAZ

I am wondering if my fuel pressure regulator is shot. But it requires a lot of removal to get to it from what I read. I wonder if it may be a ground wire problem. Thoughts?

vasinvictor

iTrader: (3)

What does a fuel pressure gauge tell you?

CJNAZ

I have not performed that test yet. Waiting on a friend to loan me a tester. Will buy one soon if he doesn't come thru. Is there a fairly easy access point to hook up the tester?

scope103

This tidbit sounds like flooding. You could have a cold start injector stuck open, or more likely, a leaky injector (you mentioned you have both spark and wet plugs). All that dirt moving around your system pre-filter change had to go somewhere, and an injector is a possibility (dirt can keep the injector from closing).

But before you send the injectors off for cleaning, be systematic. Use a timing light to verify the timing, and then put it on each plug wire to verify spark. Disconnect the cold start injector electrical wire (this probably won't help if you have a stuck injector, but it's very easy to do).

Check the compression; if good it is very unlikely to be a valve timing (timing belt) issue.

Pull the plugs, check the gap, and let the cylinders dry out. Then put them back in and try to start it.

Lay off the starter fluid if you can (that stuff'll give you cancer or a yeast infection or something). But if you can start it with starter fluid, that's evidence that you DON'T have a flooding problem.

Check the fuel pressure with a gauge. (You need the banjo bolt adapter; this kit includes it: http://www.actron.com/product_detail.php?pid=16173)

Good luck!

CJNAZ

OK, UPDATE!!! Sorry it took so long to respond back. Kids, work, etc kept me away. I went out to work on my rig yesterday. Out of curiosity I tried to start the truck. After cranking for 1-2 minutes the engine was running! A little rough for about 5 minutes then it settled in and ran fine. I ran the motor for 45 minutes. Shutting it off several times, then restarting. Each time it fired right up. Brought the RPM's up to 4500 several times and the motor sounded great. Smooth, no roughness. Run then turn off, restarted effortlessly. Repeated. All was good. While it was idling I was "feeling" hoses, vacuum lines, electrical connections, etc. to see if touching anything caused a change. When I grabbed the connector for the TPS it changed idle speeds often. Maybe the TPS?? Also, while it was idling I unplugged the MAF sensor and it ran rough. Plugged it back in and still ran rough. NO CHECK ENGINE LIGHT. Is that normal?? Restarted and it ran smooth. Drove it to the gas station and gave her half a tank of fuel then back home. No problems the whole way. Let it sit for an hour. Turned it over and it hesitated to start but did. Heavy smell of fuel.
I even took numerous videos to review later if needed. Wish I could post them here.
So, what do you think of that scenario?

Throttle Position Sensor?
ECM?
Clogged injector(s)?

Any ideas of what the hell is going on? I am confused like crazy here.