1G Fresh Rebuild No Start Issue

[Cj Anderson]

Hey Guys, I'm having issues with a new DSM build that I finally completed! Little back story about the car, I bought the car in late 2018 with the engine removed due to the transmission ear broke off on the block and also the transmission. Car was completely stock when I purchased it so I don’t know the condition of the original parts.

Over the past few years after buying the car I started acquiring parts for this build so I purchased a long block stock rebuilt 4g63 that was built with a N/A block, almost all the engine parts are new or rebuilt the only reused or used parts would be 2G MAF, TPS, coolant temp sensor and CAS.

The main issues I’m running into is the car will fire right up and then die 3-5 seconds later, I can repeat this over and over again but it will not idle. I’ve read hours and hours of posting about this issue and tried many things and can’t figure it out. I’ve checked to see if the CAS is 180 off, I’ve removed CAS and spun it to see if I can hear the injectors clicking, ECMLink shows coolant temp reads and check with ohm meter, I’ve swapped MAFs with a spare I had. I’m at the point where I sent two short log files to ECMTuning to see if they see anything wrong with the base tune.

I’ve been building this car for years but I have no experience tuning or driving this car as I bought it not running. Any helpful suggestions would be great ! I’m not in-tune with common no start issues with these cars my experience as a mechanic are in the fire apparatus field.

 

[steve]

So it starts but doesn't stay running? Post your logs, please.

 

[pat white]

Nice looking engine build !! ...can you tell if it is shutting down the fuel pump after cranking or is it like when you turn the key off?

 

[Cj Anderson]

Hey thank you and thanks for the response guys, I’ll post my logs when I get home tonight. It’s acting like I turn the key off, it’s the same run time every time it’s pretty consistent. I don’t notice the pump shutting off during start up it’s hard to hear over the exhaust, I’ll have to run my multimeter on the power to see if it’s still running. I just install the new fuel pump and used a toyota 23239-21010 oring instead of top hat, o ring and spacer to see if that helps with fuel pressure. I do notice with pump running my fuel pressure gauge shows 40psi then after shut down it drops to 20psi then almost 0 in a few seconds.

 

[Cj Anderson]

Here are two logs I took a few days ago.

 

[Vegas Smith]

1) fix your tps voltage
2) capture your wideband as well as battery voltage, stft, ltft
3) your intake temp is -74 degrees. I haven't touched a MAF in 20 years but I dont thats right.

 

[enriquez2000]

1) fix your tps voltage
2) capture your wideband as well as battery voltage, stft, ltft
3) your intake temp is -74 degrees. I haven't touched a MAF in 20 years but I dont thats right.

#3 will cause a lean condition and car will die.

Re-check MAF wires. I didn't even look at log as soon as I saw -74 in this comment

 

[Cj Anderson]

I appreciate the feed back ! I’ll do some adjustments and double check the maf wiring harness and look into the coolant sensor more! Coolant sensors wiring harness are changed out to spade terminals they maybe hook up wrong. I’ll report back with with my findings. Thank you!

 

[enriquez2000]

Coolant sensors wiring harness are changed out to spade terminals they maybe hook up wrong.

They cant go on wrong, they measure resistance to get your value. From the above its not your coolant temp its your intake temp that's a concern.

I can't remember off top of head but on speed density you can lock intake temps. Not sure MAF can do that.

 

[TuskeeTuner]

#3 will cause a lean condition and car will die.

Re-check maf wires... i didnt even look at log as soon as I saw -74 in this comment

Immediately thought of a wiring issue as soon as he said he can start it, blip the throttle, and then the car dies. Wouldn't have even thought of IATs though...was thinking FIAV, major vacuum/boost leak, or throttle switch.

Another edit...I'd double-check all the wiring between the ECU, connectors, and sensors. Make sure it matches the FSM diagrams and everything is in good shape. You're almost over the finish line!