try maf cleaner? have a known good one from the two engines?

 

Is there a typo in your donor car date? If it really was out of a '91, that could explain why the '99 ECU won't let it run right!

I bet you'd meant to type '01.


Read the OBD codes to see what codes are stored and pending. That may help point you to the issue.

 

Yes the car is a 99. The motor is an 01

 

Update. Went today and plugged in a scanner. Car started up and ran like a dream. Put the hood on and wrapped everything up the tried to start… same as last night. Noticed the rpm was at 6k with key on. Plugged in the scanner and it dropped to zero. Ar starts and runs perfect with the scanner plugged in. If we unplug scanner it dies

 

We jumped the cannus hi and low at the obd2 and it runs great. Anyone have a canbus diagram of where it runs in engine bay? Evidently it’s something cut or disconnected in the engine bay harness

 

Check the ground strap that is supposed to be connected to the back of the intake manifold.

 

dont see any ground strap. the battery has a ground to the transmission. there are a few smaller grounds. there are two grounds that connected to the back valve cover. there are a few ground wires that connect to the intake plenum on the front of the motor. there is a round wire that connects to the back of the front head above the transmission it connects to the bracket that a couple of "modules" are on beside the battery then runs to the strut tower bolt.

we tested resistance on motor to battery and 0 ohms, engine to chassis 5 ohms.

it appears to be a canbus issue. when we jump and connect the can hi and low pins at the obd2 port the car runs great. when we disconnect the jumper car dies, check engine light is on and the tack jumps to 6K with motor off. with the jumper connected when key is turned on no check engine light. with no jumper when key is turned on the check engine light is on but dim and flickery.

i appreciate all the help...

I cant find any information on what is canbus in the engine bay. im assuming thats the issue. am i barking up the wrong tree?

 

Once I helped fix my dad's Dodge pickup that had alternating bad performance like this car. You'd start the truck and engine would idle fine. The next start it ran like crap.
The problem turned out to be - worn out ignition switch.

 

thanks for the input but definitely not an ignition switch issue. that would not cause the consistent conditions we have. runs perfect when can is jumped, dies when can not jumped.

 

What are the pin location numbers of the CANs that you are jumping on this '99?

This is using Pin7 K line

 

What are the pin location numbers of the CANs that you are jumping on this '99?

View attachment 474475

This is using Pin7 K line

we are jumping pins 6 and 14
on the obd2 pinout those are labled can low and high. i didnt think this old of a car had can. i thought that it only used the j1850.

 

You have ground on 4 & 5?

 

Have not checked that. So would that cause this issue? I don’t think the scanner would provide a ground. Am I incorrect? I originally thought this was a ground issue. From the symptoms. I knew the scanner would close the can loop but didn’t think it would provide any grounding.

 

So I have an update… we were not in fact jumping pins 6 and 14… we are jumping pins 3 and 11…. This is driving me crazy.

when we use the obd2 plug from my scan tool that we unhooked and jumped the 3 and 11 car runs perfect. We bought an aftermarket obd2 plug and connected wires from same pins, 3 and 11 and it won’t run. We have confirmed with multimeter that same pins on both plugs are connected, and the resistance on scanner is 10.9 ohms, the aftermarket is 11 ohms…. Why does one work and not the other .. I also can’t find what 3 and 11 actually go to..

 

Toyota/Lexus OBD II DLC (Diagnostic Link Connector) pinout signals @ PinoutGuide.com

 

Thanks for the link. I had found that one and the Pinot skips 3 and 11. I and getting a few different out with them being vendor installed options, and the other a s a different can system

 

Can you please post a photo showing your pins 3 & 11 jumpered on the DLC3?

 

Or post a detailed picture of the port so we can see what locations are actually functional.

 

We don’t have the jumpers directly into the obd2 connector on the car. We bought an obd2 “pigtail” that plugs into it and connected the wires on the pigtail.
The obd2 pins are all universally numbered. Pins 4 and 5 which are chassis ground both have continuity to ground but have to be connected to run. Also pins 3 and 11 have to be connected. The Toyota pinout linked above and all I can find skip pins 2 and 11. I have found one that says these pins are vendor installed options and another that says it’s another CAN.

 

Given your reply, what caused you to jumper pins 3 & 11 if these pins are not identified. Jumpering random pins in the DCL3 can cause significant damage to the ECU do shorting circuits out. While it is good your engine runs with those pins jumpered, it’s amazing & lucky you didn’t damage the ECU, I think.

 

No real that hard to post a picture of your Obd port this is mine as you can see has 16 positions but only has 4 that are wired in, 4 chassis ground, 5 sensor ground, 7 K line & 16 power.

You are using something like this to jumper 4 & 5 and 3 & 11 and only than the car starts



Electrical Diagrams — 1999 Toyota Camry Solara SEV6 V6-3.0L (1MZ-FE) Service Manual | Operation CHARM

OBD port on page 6

 

Yes that’s exactly what we are using.

 

Last time I've seen something like this - it was a "floating ground" issue in the 5 volt reference circuit.

Which is used by many of the sensors on the motor.

Suggest reviewing the primary 5v reference ground(s) on the motor (Intake manifold on both the 4 cyl and v6 IIRC), and the wiring harness connections to the ECT, MAF (or MAP), Crankshaft Sensor, Camshaft Sensor, TPS, Air Intake Sensor, Knock Sensor(s), edit: and O2 sensors .. inspecting the sensor connections, the wiring harness connectors, and immediate wiring going into the engine harness.

I would also re-clean the primary grounds on the motor: especially those that bolt up to the Intake manifold, one at a time, and re-test after each for any positive effect,

+1 w/ 98LE2.2's post #16 above / links above to the other TN threads, concerning a grounding issue, which is satisfied when you plug the OBDII scanner in / completing a circuit to (internal ECM) ground,

Edit: see post #5 in the thread linked in post #16 -

https://www.toyotanation.com/threads/camry-runs-only-with-obd-pins-4-and-5-bridged-or-with-obd-scanner-plugged-in.434633/

^^ I would try this first, if here. Then I'd start inspecting/testing at the sensor(s), starting w/ the Crank and Cam sensors & wiring, looking for a bad sensor and/or wiring issue.

Hope the feedback helps.

 

Thank you.

 

i wanted to follow up on this thread and let people know we got this fixed. i didn't want to be the guy that rectified the situation and no one ever heard from them again. as many here said, as as i as well thought, it was indeed a ground. There are two harness grounds that go on studs on the back valve cover under the intake plenum. they were hooked up to the posts. The guy helping me hooked these as well as other grounds up. i kept asking him if he had the grounds on the back cover and he insisted yes. turns out he has hooked up the harness grounds but did not hook the chassis ground to that valve cover. both were on the ground point on the intake manifold. during testing, i ran a jumper from the battery negative to the back valve cover... VIOLA, fixed all the issues.... so i began looking at what gounded the cover to the chassis and found nothing connected. we switched one of the two grounds that come off the passenger side. left one at the intake and put the other on the back valve cover post and that was that, easy fix.

 

when we use the obd2 plug from my scan tool that we unhooked and jumped the 3 and 11 car runs perfect.

turns out he... did not hook the chassis ground to [the rear] valve cover.

I am studying the links 98LE2.2LCamryUS and CamryFl provided in Posts 16 and 26 along with their commentary.

Were Pins 3 and 11 on YardPro's Camry's DLC3 (OBD2) connector wired to something? Or was there perhaps some confusion about the DLC 3 (OBD2) connector's pin numbering?

Either way I am putting in my DLC3 notes a comment that folks should give attention to the ground connections at DLC3 pins 4 and 5 (edit: not 16). A "no start" that seems to resolve by jumpering pins at DLC3 strongly suggests a loose ground in the engine bay. Not that people should jumper DLC3 pins by trial and error. Instead the checks in Post #10 for Pins 4, 5, and 16 make sense, at least to me.

Edit: I see 71Corolla also nailed it, way back in Post #7. In the (365-page PDF version of the) Camry Wiring Diagram, pages 36, 69 and 70 show Ground "EC" (at the rear of the intake manifold) and its connection to Pin 5 at the DLC3 connector. I presume the reason this Camry/Solara ran with the scanner plugged in is because the scanner connects Pin 4 to Pin 5, resulting in Pin 5 now having a path to ground.

 

. I presume the reason this Camry/Solara ran with the scanner plugged in is because the scanner connects Pin 4 to Pin 5, resulting in Pin 5 now having a path to ground.

That is correct - the Scan tool is making the "bridge" <-> between ECM chassis and motor ground, in this instance.