GLi - Positive high LTFT while cruising

[engnr.mubashir]

Corolla GLi 1.3 is showing LTFT of 15, 20 25 while cruising on 80 to 100 km/h speedand average has dropped too. What could be possible cause I have recently changed fuel pump bought new from Toyota as the car was having low end response issue which got solved after changing fuel pump.
There is also slight delay in start like sometimes it starts on half crank but other time takes little longer not too much but longer than as it should be.
BTW mid range and hight end response is very good.

[kameetaha]

Make sure injectors and spark plugs are good. Long crank can be result of clogged injectors.

[kameetaha]

Is that TCC lockup issue resolved?

[dani_kk]

What do you mean?

[engnr.mubashir]

Not yet, because I haven't found anyone to sort out this issue even so called 99.99% incompetent transmission experts have no Idea what is converter clutch is and they have no Idea why and when it has to be engaged and what happens when engaged and mostly don't know how different 4 speed duper ect gear ratios are compared to manual transmission.

[dani_kk]

Dear bro, do you still face this cold start late cranking? And this happened after fuel pump replacement?

[engnr.mubashir]

Yes the problem is still there but that didn't happened after fuel pump replacement it just frequently appeared after that I notice disturbed fuel trims using torque obd app.
There is issue I'm posted in remote area as an government employees here mechanics are limited and they have nothing to check the fuel injector leaking.

[dani_kk]

The late cranking is associated with fuel injectors in that case bro. Just replace the injectors it will be fine.

Sometimes while replacing fuel pump or fuel filter assy the oring in fpr leaks and it causes this issue.
But since your problem is not during that time.
It's fuel injectors for sure.

[kameetaha]

Injectors are generally expensive, I believe he should get them tested first before getting new ones.

[dani_kk]

Bro this thing can not be tested, I have the ultrasonic bench , voltmeter resistance check. But these things are replaced on mileage Interval. I myself was facing this problem in nissan QG18de. No dtc, resistance was within boundary value, and I keep the car near to perfection.
So plugs etc everything spot on. Fue pressure was also within specification. I pulled my injectors, tested on ultrasonic bench and they were not leak, they were spraying good. The only issue was first crank was long, like 4-5 cranks and then whole day long it used to work great. One day I bought a engine for another project. I said oh yes the Injectors seem new to me so I said let's change our injectors to these one. Flow was good so used them. And the next morning when I cranked it, it started in half crank. I was surprised to know they were injectors. I changed them just randomly as a precautionary maintenance. So this happens when you don't have a dtc, and fuel filter assy is good, compression is good. You can directly jump to this conclusion.

[pwuser149383334935]

imo its fuel pressure leaking from fuel pump assembly best way is to check pressure directly on fuel assembly nozzle. leave gauge for reading more than half hour

[engnr.mubashir]

Thanks for information. It's very hard to find good quality injector and these mechanics here buy a injector blindy on dirt cheap prices and I can't trust them one of them said we will try different sets and I told I got very limited time can't visit you frequently just to try different sets of fuel injectors. I'm thinking to wait till I get back to karachi this eid.

There is no chance of FPR leaking because when I got the fuel pump change he did everything in front of me and I told him to lightly lubricate the O rings before placing FPR and Fuel pump and when he placed FPR and it perfectly snugged there and O ring was in good shape.

[engnr.mubashir]

No it's not leaking from assembly.

[engnr.mubashir]

Hello everyone who was engaged on this post the reply is update to issue I was facing.
So got my car checked from a mechanic upon troubleshooting found out that they fuel filter was chocked and due to that fuel was under performing like it was heating up and reducing fuel supply when reaching low levels of fuel or reserve. The other mechanic who installed didn't checked the fuel supply in proper way resulting in huge maintenance cost it was my negligence too when I was getting fuel pump changed didn't asked him to check the pressure.
So in the end it was decided to replace whole assembly and fuel pump to newer one due to financial situation I have delayed replacement Inshallah will get the job done within couple of month because brand new costs 45,000 to change the assembly right now not falling in budget.