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PostPosted: 29 Dec 2017 05:44 
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Country: Trinidad
Guys,

my 4g92 mivec engine seems to not be building power and im not sure where the problem is. I hear the mivec kicking in at about 5500rpm and takes its dead time to build. I upgraded my fuel pump, cold air intake, i recently changed plugs but nothing seems to work. i also did a compression test and got an average of 175 PSI across all 4. can anyone guide me on what the issue is or how i can resolve it?

kesi25
Trinidad & Tobago MIVEC


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PostPosted: 29 Dec 2017 14:36 
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Location: Auckland
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Might be time to pull some diagnostic codes from the ECU.

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1993 CB4A Lancer MR Mivec - The world's fastest Gen 1 black Lancer Mivec in Auckland with white wheels. That I own. Probably.


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PostPosted: 29 Dec 2017 17:35 
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Ok ill try that


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PostPosted: 30 Dec 2017 18:22 
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If you've upgraded the pump, that probably screwed everything up by outflowing the FPR.
A cold air intake isn't a cold air intake unless it's factory.

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6G72 mivec Twin TDO5 20Gs up and running.
Scrapheap special making exactly 280 horses at some unknown rpm.
Engine dyno under construction.

It's easier to fool someone than it is to convince someone that they've been fooled.


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PostPosted: 02 Jan 2018 05:01 
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If the fpr has been out flowed what's the fix for that?


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PostPosted: 02 Jan 2018 08:53 
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There's no point in fitting a bigger pump to a mivec. You'll find it with a search.
It always runs worse.
The fix for an outflowed FPR (happens every time with a 4G63T but they're all too stupid to figure it out) is to fit an FPR with a greater flow rate.
Most aftermarket ones are worse than stock so you need to know the flow rate.........or just go buy the biggest most expensive one you can find.
Or fit 2 or more stock ones.

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6G72 mivec Twin TDO5 20Gs up and running.
Scrapheap special making exactly 280 horses at some unknown rpm.
Engine dyno under construction.

It's easier to fool someone than it is to convince someone that they've been fooled.


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PostPosted: 05 Jan 2018 04:09 
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Joined: 11 Jul 2015 00:54
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Country: Trinidad
I have my mivec engine in a cs2 lancer. I had changed the fuel pump and fuel pressure regulator as well. As i get up to about 6k 7k rpm, i can actually feel the car hold back.

Regards.


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PostPosted: 09 Jan 2018 21:17 
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Have you actually measured the fuel pressure.

Stock, when broken and then after fixing it?


The specs are in the manual somewhere.

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6G72 mivec Twin TDO5 20Gs up and running.
Scrapheap special making exactly 280 horses at some unknown rpm.
Engine dyno under construction.

It's easier to fool someone than it is to convince someone that they've been fooled.


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PostPosted: 09 Jan 2018 23:09 
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Country: Trinidad
I have the fuel pressure set at 38 psi

Regards


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PostPosted: 10 Jan 2018 09:23 
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But that's not the answer.


What's the base pressure supposed to be?
On a turbo Mitsubishi it's 3 bar, on some N/A Mitsubishis it's 3.5 bar.
That's best set with the engine off and the pump on (bottom end of spec).

When you start the engine (vac line removed), it'll rise a bit but won't exceed the top end of spec.
When you shut the engine down it will hold the set pressure for weeks if not months.

When idling with vac line connected, it's about 10 PSI less.


That's 4 measurements that need taking.
If any of them are wrong.....they're wrong


Fitting a bigger pump ALWAYS upsets the pressure and upsets the tune.
Kids love to argue without having a clue what they're arguing about.
Every modification is a potential fail when done wrong.


Need to read the manual to find the spec for your car (the mivec engine).




So taking a guess that the spec for the 1.6 mivec is 3.5 bar (same as the Diamante 30M).......3.5 bar is about 50 PSI.
That's the base pressure.
With the engine idling with the vac on the FPR you should see about 40 PSI.

_________________
6G72 mivec Twin TDO5 20Gs up and running.
Scrapheap special making exactly 280 horses at some unknown rpm.
Engine dyno under construction.

It's easier to fool someone than it is to convince someone that they've been fooled.


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