Fuel pump confusion

Sort of like trying to time a mid sixties engine without a timing light or tach and dwell meter .

At least a code reader and multi meter are a given these days of computer controlled engines.

You will get this figured out .

For $700.00 you knew it was a project from the start

It might not hurt to check the EFI and Circuit opening relay sitting can cause strange things .

 

Right! I checked the EFI relay with my multimeter (good) and also swapped it with the same 12v box fuse used for the tail lights (which do work). No change.

I don’t recall seeing the circuit open relay when I was going through the fuse box…Can it be called something else? I can check again when I get home today. I did test all fuses under the hood and dash kick panel which all read good voltage.

 

Have you tried bypassing the IAC by feathering the throttle when you start it?

 

I have tried feathering it, lightly and half throttle a few times. It bogs out and dies with more air. Starts best with no throttle.

Hoping to get the new pump in this weekend. Going to drain all the new gas out this time. Does anyone have recommendations for a good tank cleaning agent?

 

Both POR-15 and Eastwood sell a kit for cleaning and sealing gas tanks. Unfortunately, I don't think they sell the cleaner separately and there is a possibility that if you don't use their complete kits, you may be etching the metal and then leaving it uncoated. I have used the POR-15 kit twice on old BMW gas tanks (1970's 2002 models) with great success.

First take a look inside your tank to determine the condition of the metal and the coating inside...be careful to only use a non-sparking light source and use it outdoors. If it looks good, I think a degreaser with a few rinses of fresh gas that you pour out should suffice. If it looks bad, you could consider going with one of the kits. I have no personal experience with the Eastwood product.

 

Awesome, thank you! I’ll do that

 

It has been years but airplane mechanics have the very best tank cleaning solution.

Engine quits in the air slightly different then coasting to a stop on the road.

Might be worth while to ask if you have a small airport near by.

 

Do you have an OBDII reader? Really leaning against the fuel tank problems... Check the TPS position reading if you can, check the MAF reading when you try to start it if you can get one

 

I’ll have an OBD-II scanner soon. Hard to believe I’ve gone this long without one. I’ll check out the TPS AND MAF data and update. Thank you!

 

Perfect weather out so decided while waiting for my scanner and fuel pressure test kit to arrive I’d put on new battery terminal connectors and replace the crappy Carquest fuel pump with the new Denso unit (and new strainer). While I had the tank out again, rinsed it thoroughly with fresh gas, got it all out. Inside tank looks immaculate (pics below). Hooked everything back up. Fresh gas in the tank. Took 2 cranks to get fuel through the lines, starts then dies after 2 seconds just like before. Tried about 15 times.

Either way, I wanted the Denso pump in and now I’m 99% confident this is not because of the fuel pump. I’ll update on what the scanner tells me.

One thought, when I disconnected the MAF to clean it, I tried starting it to see if it would behave any differently, and it did the exact same thing (died after 2 seconds). Could this mean a bad MAF sensor? Could a bad or stuck IAC valve do this? Injectors? Hopefully I’ll find out more when the scanner and pressure test hardware get here. Thanks again everyone

 

Might have found it! Was reading up on faulty camshaft position sensor cutting power to fuel and coils after start up. Took a peek at the wires and

Looks like the ground from the sensor to the harness is toast. I’ll wait to scan before fixing it. I don’t want to jinx it, but this could be it
PS my engine isn’t as dirty as it looks spilled some coolant removing the belt cover oops

 

*** What is interesting is the EWD for 2001 the Cam Sensor wires are Red and Green!! This is a 2001?

Unless that wire that looks yellow in the picture is really Green.

When the ECM does not see a signal from critical sensors .

The ECM thinks the engine is not running and shuts off the fuel.

That should trip the MIL in the seconds the engine is running!

Without being able to have the code point you in the correct direction your driving blind.

Good Luck Closer every step.

 

That doesn't look like a ground but shielding for the wires.

 

I thought the same thing until I was able to get a closer look and feel it. It’s definitely the black wire frayed right where the shielding ends

 

Thanks! Glad to hear I’m on the right track!

Hmmm that is strange…she’s an 01. Your eyes don’t deceive you, these are red and yellow, with a sliced black wire alongside them. I’ll update with codes asap

 

I'd still remove that old alarm, who knows what it is causing.

 

I agree LanceRN. Had a 93 4Runner that had been sitting for a few years, wouldn’t turn over. Unplugged the alarm box and fired right up. I unplugged the alarm box under the dash kick panel on this one. No more alarm going off but didn’t stop it from dying shortly after start up. The alarm was hooked up the first 5 or so times it started and ran fine. Still wondering if it could have something to do with it though…I tried reprogramming the remote without success, but was able to reset the alarm system to disarm it. Tried it with the box plugged in and disconnected, no change. I’ve left it unplugged for now

 

Well, I’m super confused. Plugged in the scanner, no codes. Went to start it to see the live data stream and the truck stayed on first try! Ran perfect and smooth for 10+ minutes until I shut it off. Idles smooth, revved just fine. WTF. I took pics of all live data on the scanner, some pertinent pics below. I have more data if anyone wants to see. Does any of it look out of whack? Now it starts but sputters out faster than before (maybe because it’s warmed up). No CEL or codes during any of this. I noticed the MAF ranged from 4.88 to 10.73 g/s during idle, then stayed in the 10’s. Spark advance 6 to 15. None of these changes happened fast. TP at 9.4% consistent at idle. What the heck could be going on?! Could the camshaft position sensor be the cause? I would think bad injectors would make it run like crap, but it runs perfect if it stays on

 

WTF, Indeed!

Since you say you didn't replace the crankshaft position sensor wire, it it possible you disturbed the wire enough to (temporarily) establish a ground again? If you have the engine running, reach down and pull on that wire back and forth and see if that causes the engine to stall.

 

I pulled out the camshaft position sensor (with wiring harness) to get a better look at it. Turns out HAVOC was right. The yellow and red wires are wire insulated within the shielding, probably to shield from electronic interference. Cleaned off the sensor, put it back in. Before plugging it back in, tried starting it unplugged. Still behaves exactly the same (starts and dies). I would think this would throw a CEL if that or the crank sensor were bad. Plugged it back in, no change. I also put a new Denso MAF sensor in. No change.

Could it be the ECU? If that was the problem, wouldn’t it not run at all during all this? I’ll check the connection and ground to ECU. I don’t want to start throwing money at random parts like I just did on the MAF…

Next ideas are igniter box, ECU or EGR. What do y’all think? Any advice is greatly appreciated cuz I’m out of ideas…