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Engine won't start after refresh- HELP!!!


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Hey folks,

 

My son scored a sweet RBP 5MT LGT sedan with 212K miles. Ran fine but seller said it had rod knock. We could not hear it but due to mileage we tore it down and refreshed bearings, rings, gaskets, etc. Turns out it had a single burned exhaust valve.

 

Anyway, this is like the 12th motor we have done with every one coming to life at first start. This one, however, would not start. Timing is dead on, valve clearances checked and in spec, but we discovered no spark signal to cylinders 2&3. Coil packs and plugs to those cylinders work perfectly when connected to 1 or 4 leads. Spark plugs are wet with fuel. Grounding straps are connected.

 

We removed covering from main plug to packs on #3 and wires looked fine. I swapped ECU from my other 2005 LGT 5MT with no change. Nothing was done to the intake manifold and wiring harness other than new intake/TGV gaskets and splicing in a coil pack plug end on #3.

 

Is there a security shutdown or something? This car is super baffling and frustrating at this point. Anyone gone through this before?

 

THANK YOU!!!

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Check for bent pins in the main harness connector...I'm guessing.

 

The service manual may help.

 

http://people.csail.mit.edu/ilh/vacation/

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Ok folks, here is an update. Couldn't get Free SSM to connect so that was not useful and may not have been anyway.

 

So, we checked/cleaned and replaced grounding straps on heads and rail on intake manifold. Found out brand new battery was stone dead AGAIN so something is draining it in two days or less. Swapped good battery and no fire- same issue. Cranks great though.

 

 

In order to eliminate the wiring as a problem, we swapped an entire intake manifold with wiring harness from a running car to his car. No change at all. So the only thing left to test ECM is to swap it into a known running car. Recall that the running car had its' ECM put in my sons car and it did not run. So put son's ECM into running car and it would not fire either.

 

So question is, if ECM from son's car is bad why won't it run with known good one? The part numbers are different so maybe that is the reason? His is 22611AJ17E and mine is 22611AJ17B. If they ARE compatible what else in the system will cause a no start in both vehicles?

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Is there something about the ECU and the Keys being married together. The service manager at the local dealership may be some help.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Is there something about the ECU and the Keys being married together. The service manager at the local dealership may be some help.

 

This. I don’t think you can just swap computers and have it work doento the security system.

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My guess is a ground wire somewhere. Did you try applying your own ground to 2 and 3 to see if the car would start? I cant access any wiring diagrams but they must be tied together somehow. Edited by 08SpecB_DE
Didnt read first post
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My guess is a ground wire somewhere. Did you try applying your own ground to 2 and 3 to see if the car would start? I cant access any wiring diagrams but they must be tied together somehow.

 

All ground wires are cleaned and present. Swapping complete wiring harness from another car didn't change anything (other than our frustration level).

 

Ugh

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So recently I rebuilt my ej25.

 

Car wouldn't fire up, just cranking forever.

 

Found my issue to be as simple as 2 connectors interchanged just like this post:

 

https://legacygt.com/forums/showpost.php?p=5287415&postcount=15

 

I know you've checked the wiring already, but it would be something I'd double check.

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I would put back the original ecu, and try the other harness, harnesses are swappable but ecu's definitely aren't. Ecu's are a pita for a lot of cars, and your using two different part numbers at that, that's a big no bueno! But if you got the same response from two different ecu's your original is probably fine.
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  • 10 months later...
That’s great!

How’d you find the correct diagnosis?

 

Rough guess: logging avcs vvt angles, total timing etc?

 

Well... here was part of the problem- a few of the OBDII connector pins were pushed in so we could not connect to a code reader or FSSM. Found that out later after scrapping the car thinking it was electrical issue in the dash= we found MICE.

 

So after doing all the diagnostics possible without a viable connection to the ECU, we pulled the motor. Absolutely knew it was on the mechanical operation of the longblock as the issue moved between cars, three different wiring harnesses, and all sensors worked fine on other cars. So removed the intake cams. BAM! there it was. The amount of misery, time, money and wasted cars that little pin caused is almost unfathomable.

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