mtnes300

I bought this as a second car a few months ago. It drove fine for the first week or two, and then one time I drove it somewhere, it it took a few seconds of strong cranking to start. I chalked it up as a fluke, but a day or two later, it did it again in a parking lot, but this time, it took longer and multiple tries. I parked it for a few days, and downloaded the service manual. I went through some steps, and thought that I couldn't hear the fuel pump running, and also I didn't see the fuel pulsation damper screw come out when I jumped the B+ to the FP positions on the little diagnostic port on the passenger side of the engine. I decided that the fuel pump was dead.

I replaced the fuel pump, and the car still refused to start. I did put my hand on the fuel pump when I was trying to start the car (still had the back seat and fuel pump cover removed) and I could feel that they were still pumping. At this point, I let the car sit for a while, and it managed to start up. I drove it around the block, and parked it and then immediately tried to start it again. No dice. I let it sit for another day, and it started again. I would take it for a loop around the neighborhood, and then return to my place. Sometimes it would start again, sometimes not.

I kept reading in the manual, and it told me to check the fuel pump circuit cutoff relay. I dug that out of the glove box area, and opened it up. The internals looked okay, and I used a bit of fine sandpaper to remove a tiny amount of black material from the contacts. I put it back together, and the car started up! I was hopeful that it was the problem, and drove it around a bit, and it seemed to start and run fine. I then left it sitting for some time, and when I came back, it started just fine and I drove it around for a while, but returned back home without turning the engine off. It had good power, all systems worked fine. The one thing I did notice, is that it smoked a tiny bit on first startup? Wasn't sure if that was just from sitting for a few weeks.

I went to drive it yesterday, and it wouldn't start. It cranks strong, but no sputtering or anything. I went online, and talked to a couple guys, and one guy said that it was probably a camshaft position sensor. I went out and bought one of those, and installed it, and still nothing. I printed off the pages from the service manual that dealt with cranks, no start, and it had me looking back at the ECU and the fuel cutoff relay.

I checked that the ECU is getting power on "run" and that the fuel cutoff relay is getting power on "crank". I re-conducted the test with the "B+" to "FP", and listened more carefully for fuel flowing in the system. It seemed like it was. It would make a flowing sound for a few seconds, and then make a different sound, but like it was still flowing.

I pulled off the little air chamber box off of the side of the intake hose, and sprayed some starting fluid into it. I went in and cranked the engine, and it cranked and then stumbled for a half a second like it was trying to start. I did this a couple times, but no start. I pulled the top cover off of the engine, got at one of the coil packs, and then pulled it out and connected an in-line spark light to see if I was getting spark. I don't know whether it was user error, or if I got a bad one from AutoZone, but it didn't light up. I'm not sure if the coil packs ground through the bolt that holds them down, but I couldn't have them in place and use the spark detector.

So, that's where I'm at. I'm hoping it's not ECU, but it looks like theres a "Sia Electronics" on eBay that people on this forum seem to have good luck with. Any other ideas? In all of this, I've had no codes or lights come up. When it runs, it runs like a champ. When it doesn't, it's totally DOA.

Thanks in advance for any ideas!

LeX2K

I would check the EFI relay they tend to run hot so the terminals corrode over time.

mtnes300

Is that the one in the engine bay, directly behind the driver side headlight? I'll have to check that out.Thank you!

Richardsr

Nad1370

Dont throw anymore parts before diagnosing.
3 thing to start any vehicle.
Air
Fuel
Spark

If any one is missing, it wont start.
Granting you have fuel and pressure is ok, check for spark.
If i remember, early 1MZ uses a 2 wire for the coil pack.
It gets its ground from the igniter so i dont think you need to ground it to check for spark.

LeX2K

Yes.

A clogged fuel filter is possible also the ECUs do sometimes go bad when they do you'll have all sorts of odd problems like no starts, stalling, misfires.

Oro

This may help you neck-down the problem with the above.

http://www.ifitjams.com/starting.htm

This will get a car started if you work through it. I agree, don't throw any more parts at it w/o really diagnosing it.

a) You can go to about any auto parts store and get loaner tools. You can get a fuel pressure tester and it will let you know if that's adequate.

b) to check for spark, just take out the plug, put it back in the coil boot, and lay the ground electrode on a solid ground, and crank. You will see spark, or not. No need to buy gadgets for that test.

Determine those two things and then go from there.

Nad1370

LeX2K

I forgot to mention the igniter (LH strut tower) sometimes goes bad this part is almost always overlooked.

Richardsr

mtnes300

Latest update. Thanks, guys. Here's what I've done since my last post:

1. Got a noid light and a spark plug light from Autozone.
2. Plugged them in, cranked engine, and nothing. No lighting up. So, no spark and no fuel injector signal.
3. I pulled the back seat out, and pulled the fuel pump cover. Put my hand on the top of the fuel pump assembly/lines and cranked and also turned the key to "run", and it didn't feel like it was pumping (which I've felt before).
4. I'm going to check the ECU fuses and relay now, and will report back.

mtnes300

Hey, reporting back. Turns out, it was the ECU / ECM. After trying the relay and fuses, we still had intermittent no start. I pulled the ECU, and opened the case, and found that some of the capacitors were leaking. I shipped it off to SIA Electronics, and it was back in two weeks (one week to diagnose and fix, one week to ship back). $135. Starts and runs fine now. I'll trust it more once I have it for a month or two with no problems.

Thanks everyone for your help!

LeX2K

Thanks for the update. The good thing about this problem is the capacitors puke their guts making the problem obvious.

Nad1370

Awesome..!
Seen a few posts here with bad capacitors on ecu's. (older cars too)
Im just glad you did it right and not throw anymore parts at it.