Cx-7 turbo upgrade

J

Jacob allen

Greenie N00B Member
Greenie Member
So I had a quick question due to my ignorance on the subject. If I upgrade my Turbo from my stock one, do I need to flash my ECU? I recently replaced my timing chain and VVT, Cam and crank position sensors, rebuilt my high pressure fuel pump, replaced injectors and fuel rail. I am beyond certain the timing was done perfectly (done almost correctly the first time minus the friction washers, which I didn't understand why they were so important to replace until afterwards, which caused a second and third attempt to set the timing and by God if I didn't do it step by step and make it look like I knew what I was doing.......) I've checked all of my grounds, adding a wire from the coil harness ground to the battery negative terminal, also replaced the intake manifold to fix the broken butterfly valve the throttle position sensor rests against, new battery. Checked voltage on the harness and continuity on hpfp, I have spark, I have 58 PSI fuel real pressure KOEO, and when cranking my pressure reaches 68 through 70 PSI. I am getting what I want to call a single combustion like it wants to attempt to start but for the one little explosion, if you want to call it that, I just continues to crank and sadly fails to start. This project has been going on for much longer than expected and has left me without a vehicle for the last 3 months, on top of forking out well over $1,000 to ride share, so if someone would be so kind as to pointing me in the right direction, and further educate me on this topic I would be ever so grateful.
 
Got that little ground wire attached to the hpfp? Also, if you upgrade the turbo, upgrade the hpfp internals and grab Versatuner, then pick a tuner company. Freek, PD Tuning, even Damond Motosports does tuning! But you do need to have a custom tune if you upgrade to something like a Corksport CST4/5
 
When cranking only getting to ~70PSI sounds like just the in tank pump. You should have the HPFP (high pressure fuel pump) bumping that up to the mid hundreds (~600 PSI) to start up.

What turbo did you upgrade to?

Did you replace the washer (between block and manifold) on the bottom bolt of the intake manifold?
 
jsmith said:
When cranking only getting to ~70PSI sounds like just the in tank pump. You should have the HPFP (high pressure fuel pump) bumping that up to the mid hundreds (~600 PSI) to start up.

What turbo did you upgrade to?

Did you replace the washer (between block and manifold) on the bottom bolt of the intake manifold?
Click to expand...
Yes I made sure to replace all bolts to the intake manifold but I have to ask................ What washer....? (lol but seriously not loling)
I know my pressure should be at least 450 min when cranking which is another ? I'm throwing. I know I am getting the pressure from the tank, what would be preventing my hpfp from pressurizing properly. I am sitting on 3 hpfps at the moment, 1 rebuilt with new internals and rings. The other two are basic stock ones I obtained and have done nothing to.

I'm at work at the moment but I'll get back to you on the turbo upgrade.
 
jsmith said:
Wrt the lower washer. The bolt it is common to on the oem manufold is shown on page 10, figure 5c in the link below. If you continue modding, maybe give em a thank you for keeping their install manuals open and available.

https://corksport.com/support/instructions/AXL-6-441-WEB.pdf
Click to expand...

OK so definitely made sure I had all of my bolts in my intake manifold.... I am wondering what washer you are talking about between the block and the intake. I never knew there was a washer between the two. Is it something that is absolutely dire that needs replaced like my friction whashers on the crankshaft?
 
Raider said:
Got that little ground wire attached to the hpfp? Also, if you upgrade the turbo, upgrade the hpfp internals and grab Versatuner, then pick a tuner company. Freek, PD Tuning, even Damond Motosports does tuning! But you do need to have a custom tune if you upgrade to something like a Corksport CST4/5
Click to expand...
So no matter what since I changed turbos from stock to something a little bigger, I HAVE to tune my car? I'm really trying to clear up the whole confusion On- Is my car not starting because it needs retuned? I'm still new to the mechanic life and I've done far more than I've ever thought to even try on my own but this is something that is completely new to me...... Kinda rocket science-ish, I've just taken a few basic classes
 
Jacob allen said:
So I had a quick question due to my ignorance on the subject. If I upgrade my Turbo from my stock one, do I need to flash my ECU? I recently replaced my timing chain and VVT, Cam and crank position sensors, rebuilt my high pressure fuel pump, replaced injectors and fuel rail. I am beyond certain the timing was done perfectly (done almost correctly the first time minus the friction washers, which I didn't understand why they were so important to replace until afterwards, which caused a second and third attempt to set the timing and by God if I didn't do it step by step and make it look like I knew what I was doing.......) I've checked all of my grounds, adding a wire from the coil harness ground to the battery negative terminal, also replaced the intake manifold to fix the broken butterfly valve the throttle position sensor rests against, new battery. Checked voltage on the harness and continuity on hpfp, I have spark, I have 58 PSI fuel real pressure KOEO, and when cranking my pressure reaches 68 through 70 PSI. I am getting what I want to call a single combustion like it wants to attempt to start but for the one little explosion, if you want to call it that, I just continues to crank and sadly fails to start. This project has been going on for much longer than expected and has left me without a vehicle for the last 3 months, on top of forking out well over $1,000 to ride share, so if someone would be so kind as to pointing me in the right direction, and further educate me on this topic I would be ever so grateful.
Click to expand...

Hi there
Did you end up finding the root cause, cause I’ve gone down the same path, however my car starts but lame when driving (but on the rare occasion perfect). I changed injector, high pressure fuel pump, map sensor, purge valve and pipe, fuel pressure valve, cleaned EGR and pipe. At my wits end - about to offload it to wrecker for next to nothing!!
 
Peter79 said:
Hi there
Did you end up finding the root cause, cause I’ve gone down the same path, however my car starts but lame when driving (but on the rare occasion perfect). I changed injector, high pressure fuel pump, map sensor, purge valve and pipe, fuel pressure valve, cleaned EGR and pipe. At my wits end - about to offload it to wrecker for next to nothing!!
Click to expand...

Start a new thread, describe what is happening what you have tried to fix and all modifications to the car
 
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