[goro66]

Hi,

I have made a few changes to my fuel system, turbo and exhaust:
3" exhaust (no cat), 15T mitsubishi turbo, larger intercooler, bigger fuel pump, 3 bar fuel pressure regulator, fuel injectors (365), camshafts (all of these I have from my (slightly tweaked) 9000 Aero.

I have installed also an APC

The car is 1993 Saab 900 convertible (Lucas). The EPROM is 27C256.

Now the only problem is this EPROM. I have bought a fuel chip from a guy but when a friend of mine checked the bin file of my original fuel chip and the new one they were absolutely the same. So the seller of the chip told me that I already had a modified chip.

We have tried both chips but when the turbo charger is set at above 0,5 bar the car is not capable of handling it (i.e. there is not enough fuel).

So can someone send me a modified bin file? (then my friend will easily reprogram the chip - the goal is about 240 to 250 hp and about 350 - 380 nm.

Any other advice will also be welcome.

If I am not able to solve this, I guess I will have to go with the Megasquirt option.

Many thanks in Advance

 

[TheRedBaron]

If your car can't handle .5 bar, something else is wrong - even with the bigger turbo in there, a stock system should be able to handle a lot more air than that - especially considering it's the lucas system (which is a little more robust than the bosch).

 

[goro66]

RedBaron, Thanks.

However my friend who has done a lot of tuning for my cars is convinced that the problem is ECU/EPROM.

 

[Breakin5speeds]

I believe with the redbaron....you should be able to handle 1bar with ease....

 

[goro66]

Thanks Breaking5speeds.

I had a further talk with my friend and he told me that interesting thing is that at all times the car has a problem after exactly 0.5 bar (i.e. not 0.55 or 0.6 or something else).

So he thinks that there may be some kind of lock or safety feature in the ECU?

Do you think that this is possible?

Best,

goro

 

[TheRedBaron]

I sincerely doubt there's any cut-off on the lucas system at that low of a pressure - but I don't know much of anything about lucas, because it wasn't offered in the US market. Perhaps one of the english chaps on board here will chime in

 

[dlb]

goro66, You said that the car has a problem after exactly 0.5 bar. Could you explain this problem? Is it like a flat spot in the power? Does it happen at the same RPM every time?

 

[idiot_saabvant]

Almost sounds like you are at base boost, and "could" be a wastegate issue. Have you checked your wastegate (If you have one)?

pierre

 

[goro66]

Thanks to all of you.

It occurs at any rpm.

Could it be the overpressure switch? I just understood that probably I have one.

Best,

Goro

 

[DanF.]

I was thinking baseboost myself. Is if possible that the APC isnt functioning? Is there a frayed wire somewhere?

Lets see some pics of the engine/exhaust?

 

[Saab-Daniel]

The LPT's CAN have a 0.5 bar overpressure-switch, so you need another fuel-chip to by-pass it. Don't really know how it sees boost though...
Daniel.

 

[dlb]

Don't really know how it sees boost though...

Maybe the AMM?

 

[Citrosaab]

Did you readjust the fuel cut switch when installing the APC?The LPT has got a limited one about 0.5bar.It´s not in the ECU, I´m running a complete CU14 from a LPT in my car, all the parts are the same compared to a FPT.
You know where it´s located?
Only the LH2.4 has got a ECU with a integrated fuel cut, it´s generated by the AMM signal.

 

[goro66]

Guys,

most probably the problem is this thing (cf. post #30) http://www.saabcentral.com/forums/showthread.php?t=73073&page=2&pp=20&highlight=overpressure+switch

I will be able to check this only on the weekend and I will keep you posted.

Best,

Goro

 

[Saab-Daniel]

Well, the AMM measures flow, not boost... So it would cut boost according to flow, which would limit the car to a smaller amount of boost, if you fitted a larger turbo.
Ohh well, let's see what happens when the overboost pressureswitch is remove/adjusted.
Daniel.

 

[goro66]

Well, the overpressure switch was taken care of (it was disconnected). However only a slight improvement. Now the thing happens after 0.7 bar.

My friend still thinks that the problem is with the ECU. Unfortunately in my country most of the cars are Bosch and not Lucas so about the latter we do not have much experience.