2 Issues Strange Cranking Noise and Long Idle Issue

[stolensupra]

Hey guys I have a couple issues going on with my supra post rebuild. Any help from the superstars on this site would be greatly appreciated.
First off mods list.
1500 Miles on full rebuild. 7mgte
Block bored with head for Cometic MHG ARP Bolts
Probe .40 over Pistons
AEM AFPR
ARP Internal hardware
Spec Stage 3 Clutch
Rotating Assembly fully balanced.
Shot peened/reconditioned stock rods/ ARP
3 angle valve job.
All New Gaskets
MSD 8mm Super conductors
Wastegate shimmed to 13 psi on ct26
Charcoal Canister, Evap System, EGR delete.
Apexi Power Intake
BIC Knockoff DDP 3" open downpipe
Innovate LM-1 Wideband
Everything else stock.


My car still has the cold start injector but when cranking from cold it takes a solid 20 seconds of cranking to fire up then once actual combustion is achieved it may or may not keep running may require one more crank of 5 sec or less. This is one issue. Simultaneously when doing this I hear this high pitched whining sound not as shrill as a belt squeal it almost sounds the way an electric drill does when you're just barely pulling the trigger and there is electromagnetism flowing but not enough to turn the chuck.

Ok those are actually two of my problems and I have a third one.

I usually let my supra Idle extended periods (5-12 minutes) when I'm somewhere like a store with good visibility, about to leave work etc. According to my wideband my idle usually sits at about 14.7 but has been as lean as 15.7 and as rich as 13.5 About 25% of the time when I do this I'll begin to leave and my car will die right when I rev to engage the clutch. Then when I go to restart it's difficult to achieve combustion for about 20 seconds of cranking; frequently backfiring in the process and this is on a completely warm engine, no smoke, perfect operation when running good. I'm perplexed. Any help would be very very appreciated.

 

[Nick M]

My car still has the cold start injector but when cranking from cold it takes a solid 20 seconds of cranking to fire up then once actual combustion is achieved it may or may not keep running may require one more crank of 5 sec or less.

I would start here.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=112

That is the cold start circuit. Just because it is plugged in doesn't mean it is working.

Pull codes. There are a few things you would be looking for. DTC 22 is the engine coolant temp circuit. If the circuit is disconnected, you will get a hot start which will make it run bad until it warms.

So you have the stock fuel pump? How much fuel pressure do you have when the vehicle is off?

Simultaneously when doing this I hear this high pitched whining sound not as shrill as a belt squeal it almost sounds the way an electric drill does when you're just barely pulling the trigger and there is electromagnetism flowing but not enough to turn the chuck.

The starter has a clutch on it to save the starter when the engine fires. It will free wheel when the engine starts, and locks when cranking. When they go bad, they scream for mercy. And it sounds similar to your description.

I usually let my supra Idle extended periods (5-12 minutes) when I'm somewhere like a store with good visibility, about to leave work etc. According to my wideband my idle usually sits at about 14.7 but has been as lean as 15.7 and as rich as 13.5 About 25% of the time when I do this I'll begin to leave and my car will die right when I rev to engage the clutch. Then when I go to restart it's difficult to achieve combustion for about 20 seconds of cranking; frequently backfiring in the process and this is on a completely warm engine, no smoke, perfect operation when running good. I'm perplexed. Any help would be very very appreciated.

Pull codes. Does it run just fine once it is running and past the rough patch? You are describing A/F symptoms. And this symptom of a hot restart is different than a cold start. There is vacuum switch that raises fuel pressure for hot restarts. I wonder if it is working right with the vacuum lines you took off during the canister and EGR delete.

 

[stolensupra]

Thanks for all that info Nick! When I get back home I'm definitely going to do the check on the CSI time switch. I'll get back to you on the fuel pressure when not on. I'd like to nail all this down. The explanation about the starter sounds correct I'll try to get a video or sound clip of it and maybe see if you can confirm the sound; if you wouldn't mind.

]


Pull codes. Does it run just fine once it is running and past the rough patch? You are describing A/F symptoms. And this symptom of a hot restart is different than a cold start. There is vacuum switch that raises fuel pressure for hot restarts. I wonder if it is working right with the vacuum lines you took off during the canister and EGR delete.

Yes it does run fine once it's running and past the rough patch but I'm not turning the vehicle off intentionally it's when I go to leave after an extended idle with the car still running that it will die and then backfire and require an extended crank to restart. I just don't get why it will idle perfectly, sputter and die upon takeoff, then be difficult to restart. Then when back up and running it's a smooth beast again.

Thanks again for your help!