Let me clarify this is not my car but my friends and I do work on it a lot so I would like some help to fix it. Thanks ahead of time.

We have a FD with a 20B / Borg Warner S400 setup built with a massive radiator (4" thick, 28" wide, 18?" tall) and a nice FMIC. The ECU is a Microtech LTX12, the coils are Bosch 715s, the injectors are 850cc primaries, 1600cc Bosch secondaries. The problems we are having is that the car ran great for a little while after we got the car back from Florida (built in FL) and recently the car began to have problems idling properly and now is running quite rough at low RPM's.

The car will idle somewhat while cold but still needs a little (1k rpm) help. After the car heats up the car will have more problems idling below 1500rpm (hot start problems also). Now I've changed all the spark plugs and coils but still to no avail. I've checked and double checked all the wiring. I've swapped batteries, swapped starters, redone ground wires, checked TPS, there is no external map sensor (as far as I know, they are built into the ECU) but that never made any problems before.

The car will run very smoothly at high RPM's (above 4000) and has no problems driving at that speed(still don't drive it). The car is setup to run 17 psi but is currently running 8 psi for streetability. We previously swapped out the crank angle sensor (similar to the FC style) and it fixed this problem before but this is a brand new one so I don't see why this would be messing up (I can still check if you offer a way to check it without pulling it out).

We just got the car not too long ago but we are hoping to be able to fix it so we can enjoy the full 17 psi!

Any ideas? I have access to about any part I may need to check if you have a suggestion.

 

Oh yeah, I'm sure everyone wants pictures seeing as this has never been mentioned before. I'll get some for you. This car is amazing. Makes me cry not to see her run.

 

I have no expirience with 20b, but,

* Did you try re adjusting the fuel parameters ? maybe compensation map for different regions needs a bit of tweaking.

* And did you check timming ? is it set correctly .

* And Vaccum leaks are also a big one for idle , did you triple check to see theres no vaccum leaks anywhere, map sensor is connected , etc..

 

Thanks for youre help. All the vacuum lines are stainless lines that are threaded so they are not leaking but I will double check them.

I'll double check the timing but could someone suggest how to do that exactly?

I will def check out the fuel parameters but I do think they are right since the A/F is good at idle. I will probably try to lean it out a bit at idle though.

Thanks for the reply.

 

pmed you

 

I'd like to see this car.

 

When you check for vacuum leaks, use some throttle body cleaner and spray every intake seem. Ya never know! Also, it could be possible that your coils are malfunctioning.

 

I have had a few microtech LT-12's and LTX-12's have severe glitching issues at various rpms. Its a problem with the LTX-12 mostly due to internal ignitors, they get hot and mess with the main board. Do a data-log and you may find the rpms signal to be erractic. If so pull it and send it back to microtech for a new one. Or better yet, just get a electromotive or Haltech standalone, and spare the headache (personal experience talking here).

 

pmed you the info for the microtech tuner building my car....3 hours from you. he is the cheapest you will find

 

check compression

its probably fine, but it is an easy test and then you get that out of the way

also can you monitor fuel pressure? You could have a pump issue causeing low pressure....

 

check compression and take a look at your vacuum gauge. how many inches of vacuum is the engine pulling?

 

I will check thanks for your replies. I'll try to get some pics too.

 

I think you have ignition problems...
if you dont have any problems with your compression then the problem is your ignition, I had the same problem on my 20b last week.

It starts and runs bad on idle, a way to find out is, to check the ignition by the spark pluggs and the ignition wires. put one used spark plugg on the wire and try the ignition, it should show a strong spark! (blitz).

 

If you want to see this car please feel free to call my cell phone and come over. The owner doesn't mind and actually likes to talk about 7's. (919)827-3613

 

My computer is not letting me upload so Ill add more tomorrow.

 

The main crank pulley has movement now. I do not know if it was like this before but the pulley moves about 3mm as it rotates. I don't know if it is adjustable or if the engine is damaged. The turbo has shaft play and is spitting oil now as I have found a broken oil return line that almost caught the engine on fire. I suspect we will just swap a different engine in place of this one.

 

Sounds like the front thrust bearings are toast, most likely due to a crank pulley being removed at some time, and a thrust bearing fell down, and then was crushed on re-assembly.

 

I meant to post the pics sooner but better late than never.

 

Plenty more available if interested.

 

motor is absolutely sick...... but put the stock headlights back on.

 

Yeah I don't like the headlights either.

 

What ever was the diagnosis? Was the thrust bearing the culprit?

 

The owner hasn't decided what he wants to do yet. He wasn't very happy when I told him I couldn't just swap it out for one of his other 20B's because this one was made out of 13B plates and mounted on the stock sub frame. I hope to have it running again before the damn thing rots. It's sad.

Strangely, there are plans and parts for his next FD, P-port custom forged block; GT300 RE-A Widebody, SSR 11" wheels (335 wide), more to come.

 

May I ask who built the car in FL?

 

Here's another one to check. Ignition breakup because of RF interference at the CAS. Huge problem with the Haltech (E6X). I know this is Microtech, but they can have similar issues with RF interference.