Jump to content

Superspecies Engine Swap


deano266

Recommended Posts

With all the troubles I have had with my rover t series (it will now only run 6 miles before stopping completely), me and my father were thinking of maybe looking at putting aazda mx5 engine in. We know it will need new engine mounts, gearbox mounts and propshaft as well as the ECU that comes with the engine (to keep costs low for now).

 

My question is. What else will I need besides these and a bit of plumbing

Link to comment
Share on other sites

It should do, doesn't it currently use an adaptor plate to fit the T Series? Not sure how the hole would affect mounting the starter motor.

 

It sounds like a lot of work to fix something that probably an ECU issue - especially if you have to buy an ECU for the new engine.

Link to comment
Share on other sites

That's not a bad suggestion really, Rich, when you think about it - if you're ready to commit to an engine swap that involves an aftermarket ECU, why not just try the ECU route now on the existing engine and see if it resolves all the issues, in which case you've saved yourself a wealth of work. If not, well, you've at least done the hard part of the wiring/ECU ready for the engine swap itself...

Link to comment
Share on other sites

That's a bit of a nuclear option to solve your problem :) And as it all started when you rewired the car, I guess it's a fair assumption that this is a wiring problem. What does MEMSAnalyser show at the point where the engine stops ? And what does it show when you try and start it again ?

Link to comment
Share on other sites

OK so to start you know it's loosing it's spark as it's still getting fuel

Get a timing light clip it on a lead when it stops and see at what point it's loosing the spark

If it's coil run a temp lead from battery and see if it starts

If a fault is random it's a pain to find but you know your fault will happen so a logical approach should find it quite quick

Link to comment
Share on other sites

Hi are you running full injection?

The reason I ask is I'd probably look at crank sensor as a car can idle for ages but when driving heat soak can cause it to break down

But if full management I'd doubt you'd get flooding as inj would not fire

Can you scan the car and record live data ???

Link to comment
Share on other sites

well I managed to run the car today but only got a 3 minute run before the car came to a halt. The plugs were dripping with fuel as the engine came to a slow halt whilst going along. For anyone interested in the file drop me a pm so I can send it to you

Link to comment
Share on other sites

Ok, got the file thanks. It does have some odd things in it though. We can see from the trace that the engine stops running at 2:41 and the ECU stops at 3:20. We can see that 2:38 you have the throttle wide open trying to keep the engine running, but the RPM drops to zero 3 seconds later.

 

1. There is something wrong with the alternator. All of my logs (and AndyW's) we get a fixed voltage around 13.7V +/- 0.1V until the engine stops, at which point it drops down to 12.6V, the sign of a charged battery. Yours looks very poor, starts at 13.1V dropping to 12.4V before stabilising at 13.0V. But at 2:25, 16 seconds before the engine stops, something very weird happens, the voltage starts to drop and it is at 12.4V when the engine stops but continues down to 11V before the ECU switches off. Very suspicious.

 

msg-12714-0-41123200-1540585391_thumb.jp

 

2. When the engine stops the stepper motor should reset the IAC (Inlet Air Control) position back to the idle. As you can see from the side-by-side pictures, mine does that but yours doesn't. Might explain your difficulty in restarting. However, this may be because you do not turn off the ignition so that might be a red herring. If you close the engine down normally do you hear the clicking of the stepper motor?

 

msg-12714-0-61306600-1540586641_thumb.jp

 

3. Not sure what to make of this one, but we have one of the parameters that we aren't sure of, but it has been suggested it is the fuel/air ratio. On my car that has never varied from 145 (14.5 to 1.0 ?) but as you can see from the picture, at the instant your problem occured it suddenly took a sharp dip. No idea what that means.

 

msg-12714-0-02935300-1540587006_thumb.jp

 

4. There is a byte that we refer to as Long Term Fuel Trim, although I am not personally convinced. The default setting is 128 (256/2). Mine used to be 119 but over the years has gradually drifted down to 112. I see yours is 108, which seems a bit low.

 

And finally we have your Air Temp Sensor failure light. It seems a bit odd, as we can see that the ECU is actually registering a temperature. However, on all my log files the Intake Air Temperature and the Fuel Temperature generally follow each other. On yours they are radically different. In fact at the start of the run the Intake Air Temperature is showing as 95 deg C and then comes down instead of up. I think that is highly unlikely :) But I assume you see the same behaviour with the sensor disconnected ?

 

Everything else seems OK. So not much help really although I find the alternator behaviour a bit worrying and I know you have had problems with it before. Send me any more log files you do so we can see if there is a pattern.

 

Cheers

 

Al

 

Link to comment
Share on other sites

Al forwarded me your MEMS logfile to look at, and I agree with his comments.

As we've mentioned before, you've got something wrong with your air temp sensor as it's showing a fault code. But very oddly it seems to be producing inverted values, starting with high temps and getting cooler as the engine warms. Either the sensor is duff or it's the wrong type, or it's connected wrongly. Did you make the checks I suggested previously? Disconnect the multiplug and check the resistance across the sensor pins - it should be about 2400 ohms at temp 20 deg C (range from the manual is 5700 ohms at 0 deg and 1100 ohms at 40 deg C). Also, with multiplug connected and ignition on, check the voltage the sensor is providing to the ECU - at 10 deg C temp, the green/black wire (to ECU pin 16) should show about 2.8 volts, and the pink/black wire (to ECU pin 30) should show an earth.

Also as Al says, your battery voltage looks very odd, and I wonder if this is the root cause of your issues. The alternator output when running isn't high enough, as it should be in the region of 13.4-13.7 v, but yours is mostly 13v and below. Also it doesn't look very steady or consistent, whereas mine stays 13.5v +/- 0.1v for the whole of a journey until turning off when mine drops to battery voltage about 12.4v. The end of your log shows the battery voltage gradually tailing off down to 11.5 v over a minute which is not normal behaviour. It's as though your battery isn't holding voltage, or the alternator output is declining.

Engine voltage is critical to many MEMS functions, including air flow calculations, stepper motor control and resetting it after stopping, and coil output. I just wonder if this is the cause of the problems you are seeing. If the voltage is declining after driving for a while maybe the ECU can't function properly and is shutting down? I would get your alternator and battery checked, as well as the wiring between them and all their earth points.

Cheers, Andy

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...