OBDC code interpretation for 1996 9000 low pressure turbo

[DavidR]

1996 9000 5 speed 4 door 2.3 liter low pressrue turbo. 130,000 miles (original clutch). Rebuilt turbo installed about 4 months ago. Car runs great but check engine light is on. I borrowed an OBDC cable and downloaded the software to diagnose the "Check Engine" light. The dealer had previously charged me $145 to say it was "plug misifre" and replaced some vacuum hoses. It has new Bosch plugs. When I plugged in my laptop, I got two codes, Misfire and Camshaft Position. Where do I go from here?

[duesenberg]

I think You should start from spark plugs. Bosch plugs are definitely very good, but not on Saab 2,0 and 2,3 engines.
For those engines NGK BCPR6ES (gap 1,0 +0,1/-0,2mm) are best and recommended. Those plugs measuring also ionization inside cylinder.
Does "check engine" light shows any code when You switch on ignition?

duesenberg

[Paul]

I would agree with that, Saabs like NGK plugs a lot!!

I wouldn't use anything else after my own bad experiences with my C900 and Bosch plugs....

[DavidR]

Did you mean BCPR6ES or BCPR7ES? The manual says 7. 6's are readily available at my local parts store, 7's are only avaialable at the dealer for some reason.

Are the factory gaps usually OK?

I will post the exact codes - I have to go back out and hook up the laptop...

[Paul]

Your car would take: BCPR7ES-11

I would always recommend checking the gaps yourself, easily done with a feeler gauge.

[DavidR]

OK, PCBR7ES plugs it is!!

The codes are:
PO300 R M Mis (Random/Multiple Cylinder Misfire)
PO340 Cam A (Camshaft Position Sensor A Circuit)

[Paul]

Personally I would fit the NGK plugs before doing any more diagnostics on the Check engine codes, both problems *could* be down to the fact that you are using the Bosch plugs.

When I fitted them to my C900 the car wouldn't fire at all, as soon as I put in the NGK plugs all was fine. This is despite the fact that the Bosch plugs are supposedly compatible.....

[DavidR]

Hey, guys - I put in the NGK plugs and reset the Check Engine code. Before I fire her up, is 1/2 turn past hand tight still the way to put in plugs?

[DavidR]

Well, I ran the car today (with the NGK plugs), the Check Engine light stayed off. But, now the car has a hesitation as if the turbo boost is reduced, around 2500 RPM under half to full throttle, like getting on the highway or passing on the highway. It ran better with the Bosch plugs but the Check Engine light was really bothering me.

Rats.

Any suggestions of where to look now?

Oh, yes, one more oddity - the temperature never gets to the middle of the normal range - the needle moves about 15% of the range and stays there. Can a low temperature affect engine performance?

[Guest]

The DI cartridge is very sensitive to the correct plug type. It must be fitted with resistive spark plugs. AFAIK NGK are the only manufacturer who sell them. The resitive element is designated by the R in the coding as in BCPR7ES. Fit anything other than a resistive spark plug and apart from running badly, you may also damage your DI cassette.

I'm afraid to say the symptoms that you now describe are characterstic of DI casssette failure. Diagnosis is to obtain a known good one and try it.

NGK BCPR7s are widely available- although not necessarily pre-gapped to the recommended 1.1 mm (NGK BCPR7ES-11)

6's are the wrong heat range for turbos, but OK for NA's

Your temp gauge is a placebo- it doesn't read the real temp at all. The original 9000 gauges were very "dynamic" which caused some concern amongst drivers, so post about 1994 the design was changed and they are now driven by the ECU, not directly connected to the sender. They indicate when the temp is cold, but rarely move above about 8 o clock once running.

If your engine runs slightly cold you will get better performance but worse economy; slighlty hot you'll get worse performance but better economy.