Confusing spark problem

[guymalpass]

Hi,
I hadn't driven my MR2 for about a year and when I came to start it up all it would do was turn over. The odd thing is if I leave it for a few hours and try again it will start up for a few seconds but it sounds rough and then dies. After that there is no spark unless I leave it for a few more hours.

I have replaced the coil and igniter and tested the HT leads and signal generators according to the BGB. The fact that will occasionally start up briefly also leads me to believe they are probably fine.

So I'm starting to think maybe its the ECU? I also tried to see if there were any diagnostic codes my jumping T and E1 but the engine light just stays on constantly. Is that a symptom of bad ecu?

Many thanks,
Guy

[Torero]

I don't mean to make you sound like a noob but is there a fuel supply to the injectors?

Anything in particular that makes you think it's an electrical issue.

[MRPagey]

When you say no spark, how are you testing for spark?
You've checked the HT leads, does that include the king lead that goes from the ignitor to the dizzy cap?
Have you checked inside the dizzy cap to make sure the contacts are good and not covered in white deposit? Is the rotor arm alright?
Does the car have an aftermarket immobiliser or ECU?

[mickybo]

have you used fresh petrol or are you using the petrol that was left in it 2 years ago?

[guymalpass]

Thanks for the replies, I have a spark tester that flashes. On the odd occasion the engine starts then sure enough the tester flashes but after it dies then no spark. Yes I pulled the dizzy cap off and cleaned up the rotor and contacts. To eliminate dizzy problems I even tried to get a spark directly from the coil to ground (I know you shouldn't do this really) and nothing. Yes in fairness its the same fuel that's been sat around, if its still a problem when I get the spark sorted I'll drain and replace.

[guymalpass]

Forgot to mention- also checked the king lead according to BGB and jumped the Fp terminal in the diagnostic port so the fuel pump constantly runs to eliminate relay problems. I haven't checked the injectors, how could i tell if they were good or not?

[MR2DI4]

More likely bad fuel or even more likely the fuel pump has packed a sad.

Short the B+ and the FP+ in the diagnostic box and check if the fuel pump is running. You can check by squeezing the fuel return line to feel the vibration or if you have good ears you may be able to hear the pump in the gear shift area of the centre console.

The battery would be stuffed if you left it a year without charging it or running the car.

[guymalpass]

Yes I have tried shorting the FP and B terminals and there is fuel going down the return line. I stored the battery separately so its in good shape. If the fuel was bad does that explain the spark problem?

[mickybo]

I had similar symptoms about 3 months ago, turned out my battery was dead, changed it viola, all good. I even jump started it left barely running kept wanting to cut out unless I kept my foot on the throttle, had no power wouldn't even rev.

[adamstanford]

batteries still lose charge when not connected to anything and a used battery might be even more so. How old is it?

[guymalpass]

The battery is about 18 months old, Odyssey AGM type. Freshly charged with a CTEK charger for AGM batteries, I'll have a hunt around for another battery though and give it a try!

[MRPagey]

Isn't the little green relay in the boot, bolted to the wall next to the ECU something to do with the spark?

[dawesy]

Nope [emoji20]


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[jimi]

Bearing in mind that it's a MK1

To go back the the OP's first post, I'd be concerned that you can't get the ECU into diagnostic mode. I'd be trying it again, make sure you have a good connection to E1 and T, the check connector sockets can get a bit corroded, give them a clean up. Are you sing the correct method ? http://www.mr2oc.co.uk/know-your-2-know ... kbartid=61