Cold engine will not get past 2kRPM

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Nov 23, 2017 7:49 pm

Nope. 5g are OBD1. Diagnostics is by code read on lights on the dashboard or plugging in to the serial connector (2 or 3 pin? I forget which...) with relevant software to read live data.

ECU wise, the thing that changes as the engine warms up is that it switches from using the coolant temperature sensor to the lambda sensor, to control mixture. I just wonder if that's related, but I can't really see how it would cause a restriction on engine revs. Even vtec being restricted by low engine temp wouldn't result in the revs being rather held that low....

A knackered temperature sensor causes engine revs to race a bit at idle, so it's unlikely to be that. You could try changing the lambda sensor though, could be that.

Post by **RattyMcClelland** » Thu Nov 23, 2017 10:41 pm

wurlycorner wrote:Nope. 5g are OBD1. .

You meant obd2. 5th gens are obd2. All cars from 1996 onwards are. However we don't have the obd2 port that was introduced in the late 90s.

Post by **Vtecmec** » Thu Nov 23, 2017 11:11 pm

Does it just cut out dead, or splutter then die?

AeroNotix · Post by **AeroNotix** » Fri Nov 24, 2017 4:15 pm

It doesn't die or splutter. It just seems to get "stuck" at 2-2.5k and won't rev past that in gear.

Is there any way to get live data from the 5th gens? It'd help in seeing if the lambda sensor is doing anything before I replace. I'd expect to be able to get live data somehow. I can do this on my 98 mini!

Post by **4thgenphil** » Fri Nov 24, 2017 4:24 pm

Atooopid question, is you throttle cable tight and still attached to the bracket?

AeroNotix · Post by **AeroNotix** » Fri Nov 24, 2017 5:21 pm

Yep. Car drives fine normally. There's a bit of slack in the throttle cable but I'm talking maybe 3mm of slack.

AeroNotix · Post by **AeroNotix** » Fri Nov 24, 2017 5:32 pm

Hey so. I've got the 2 and 3 pin diagnostic cables. There's a 3 pin to 16 pin (odb2) adapter. If I get the adapter or make one will it "just work" as a regular odb2 diag port?