LA2 or LA3 Swap Without re-pining

[jamman]

It would be truly appreciated if you could get some close-ups !!

Thanks !

[trainford308]

Here are two pictures of the cuts. The first picture is of the cut at the conector. The second picture shows the two cuts on the board. The one cut is below the C7 and the other is beside the C 24 markings on the board. The cuts look like scuff marks. That is the coating on the board. I hope this helps. Tom

[jamman]

Tom

Thanks much this is great !

Gary

[MeZapU]

I just did this to a LA2 for my SVO. Worked great. I'm much happier with the LA2 vs the PE in the way my car now drives.

You may want to edit the pictures with colored arrows or circles to point out all the circuit board modifications. Some of them were hard to see and would be pretty tough for someone not familiar with circuit boards to spot. But maybe I' was to analytical as to tracing runs rather than just getting on with the process.

I wired the ACT sensor to the unused pin #41. I'll probably end up installing one in the next few weeks.

[SVOeric]

???? you like the la2 better than a PE ?
You'd be the first person I've ever heard say that

[jamman]

Started to mod my LA3 .. Will let you know how it turns out ..

BTW - I popped off the kick panel to get ready to remove the PE, looks like there is only one screw on the plastic fitting holding the computer, is that the only one I need to remove to get it out ?

The little back plastic shields were a little fun getting out ..

Thanks !

[jamman]

Ok thanks Mike,

Got the board rewired so now I need to plug her in and see how it goes !

[SVOinDC]

Like my LA2 much better than the PE. So I guess that would make two.

[jamman]

Popped by LA3 in and it seems to work but I have not taken it out of the garage yet due to bad weather here today to really put it thru the paces ..


Just revving it up it seems to run ok ...

My idle is still not good though ... I thought the LA3 would be much better so it must be an engine issue ..

My base idle is at 900 rpm's and it misses quite a bit at that RPM but it's fine when it hits 1300 RPMs and higher, the car runs great ...

It has Siemens gray top 895's in it which are 34.8 lb injectors from what I found - they were used by the 2.5 Dodge turbo's ...

Has new plugs and new O2 also and recent distributor cap

Previous owner had the head rebuilt with a roller cam installed not sure what kind and what the specs are for it ...

[Rob.]

Drive it.

Go take it for a drive. When I first put in my LA3 my car ran like crap. I was soooo pissed. It takes the EEC some time to "learn" your motor. It will be running really rough then....>BAM<... all is right with the world once again. I'm sure some of the more knowledgeable people(Mr. FLemming) here could tell you approximately how many revolutions it takes for the EEC to dial it in. If your car ran fine before your changed EEC's and now runs rough, there is probably nothing wrong. Go drive it, soon you'll be enjoying a MUCH smoother running car. The LAx series is not quite as aggressive as a PE, but what you gain is more usefull and noticable. You can also get a J-3 chip interface if you want to tune it to be more aggressive.

[jamman]

The idle was rough with the classic PE miss and idle hunt between 900 to 1100 RPM, so I thought it was just the typical PE hunt-miss thing ...

The head was rebuilt (with roller cam), block decked and replaced 4K miles ago and the Siemens injectors were added then as well as a new timing belt, IAC and water pump .. I just put in new plugs and O2 last week and it passed inspection with flying colors ...

I have idled the car in the garage for a total of about 15 mins, when it warms up the idle drops to 900 RPM is still hunts up to 1100 RPM and back to 900 etc .. Vacuum is 12 at 1100 PRM and 8 at 900 RPM and bounces back and forth during the hunt ..

I'll take it out for a spin and see if it improves ... I hope so !

Any other tips are welcome ...

[caroth]

The P and L series processors are not adaptive like the A9L stuff. If the car is running rough, there is a problem with a sensor, vacuum leak, dirty injectors, weak fuel pump, or wiring issue. Pulling codes is always the first step to track down the issue.

You mention Dodge turbo injectors, some of those injectors needed a base fuel pressure of 50psi or so. If the idle is hunting, it could be from a lean condition, or a vacuum leak. I chased a hunting idle for years and finally found it to be a bypass valve leaking.

It is probably best to not hijack this thread trying to figure out your problem. Start a new thread if possible.

Chris

[jamman]

I have a manual boost gauge so with the LA3 will the turbo still have the same boost levels as with the PE ??

Just curious ...

Guess I'll find out when I finally get some plates on in and take it out for a nice high speed drive

[jamman]

I met with Chris Roth last night and he programmed my F3 module to put on the La3 ..

Thanks again Chris I can't wait to try it this weekend !

We discussed that possibly the cam might be contributing to the rough idle also ...

[SVOeric]

Chris is so good at it, he can probably do it in his sleep!