Am having problems with my 90 spec RST, its been off the road for about 6 or so years and am struggling to get it to fire up properly.

I've had it running very briefly but was running very rough and rich, wouldn't idle and was difficult to start.

Have cleaned out the fuel system, tank off and washed out, blown through the fuel lines and replaced the filter, barely managed to get it to fire up and was running like a bag of shite basically !!

Thinking it was the metering head at fault i got another one and tried it and its exactly the same !

Getting plenty fuel pressure going into the metering head and also at the cold start valve but getting next to nothing at the injector pipes, dont get anything when pressing down on the flap either !!

Anyone got any ideas where i should be looking to try and cure this !!

 

just because you have fuel dosent nessisarly mean you have the correct pressure. you really need fuel pressure testing equipment to check you have the correct pressures in the upper and lower chambers.

 

i have this sort of problem and the reason for the problem was the switch on the side of the metering unit and also i needed to clean the metering unit
Cleaned the metering unit and replaced the switch as the terminals had rusted over and cars runs lovely

Also you might need to adjust the metering head using the alloy key on the top of the metering unit

 

clean all electrical connections to and from the metering unit and all sensor plugs and pins specifically coolant and air temp (under manifold and on cross over pipe), unplug the black box on the side of the head and re-try (with a warm engine if you can get it to run enough to warm up),

Let us know if the problem improves with the EMFPA unplugged as this is a good place to start fault finding.

Rob,

 

Can anyone help with a wiring digram or tell me which multi plug goes where on the engine ( the one's round the back mainly! ) as i bought the car without and engine and want to be sure i have each plug connected up to the correct valve/sensor !!

 

theres a picture on here somewhere

 

they are all colour coded, you cant go wrong

 

+1 All got little coloured strips on them.

 

Had this running again last night after changing the pump and the accumulator, still running very rough and will not idle.

It will rev up not too bad but struggles to hold a constant rev and almost starts to shudder, not quite like an HT misfire but more of a fuelling problem i would say possibly.

It ran for about 2 mins then kind of spluttered to a halt and then refused to start after that !

I bridged out the fuel pump relay and loosened off one of the injector pipes at the metering head, got a decent amount of fuel coming out when i pushed the flap down but for some reason when its all back together its not injecting fuel at the injectors!

Can hear the pump running fine and there is plenty of fuel in it so am wondering where i should be looking next ????

 

have you replaced/checked the following.

Ht leads replaced and in the correct order

spark plugs replaced and in goood working order

dizzie in correct position and in good working order

timming all timed up.

when you rev dose it rev fine ? and what rpm is it ideing at ?

possobly adjust the little grub screw to tighen the trottle cable up abit ...

 

i had this problem and changed eveything on the car, inlet, metering unit twice, fuel ecu, loom, plugs, leads, dizzy twice, cam, turbo, ACT sensor, TPS, WTS, cold start, pump, filter, fuel lines, fuel tank, still ran like shit. Gave up in the end and sold it, still the same today, only thing unchanged was the main ecu so try that

just ditch mfi and go megasquirt or cossie managment, much less hassle

 

HT leads are fine, new plugs, dizzy is in correct position give or take a degree or two as not had it running for long enough to get the timing adjusted to correct position !
Cam timing is spot on, when it revs it will rev up fairly decent ish but will not hold a constant rev and starts to splutter and miss, clears its self when you give it a rev though !

 

I might have to try another ecu as everything i have tried so far is making no difference !
Its the original main ecu thats on the car (hearts and diamonds) but am using anther fuel ecu as there was none fitted to the car when i bought it !

 

Sounds like its possibly overfueling to me. I would take it to a tuner before you waste any more time and money.

 

yeh mate its worth a try, mine was running sweet for 3 days after being run for the first time in 5 years then just started running really shite and was just borewashing, only way it would run okish was with coldstart unplugged

 

Tried another ecu tonight and still non start !

Have noticed though that the engine i have fitted to the car has a crank sensor but there is no wiring in the loom for it, does the hearts and diamonds ecu need to see a signal from the crank sensor in order for it to run properly ?? Maybe when i've had it running recently its only been off the cold start valve as will only run for about 2 mins then cuts out and will not start again !

Some of the earlier models dont have crank sensors fitted do they ?

 

mfi managment doesnt use any pick up from the flywheel, just sends a signal out to the dizzy, are you getting a spark at the plugs? dizzy cap could have a hairline crack in it, coil faulty, king lead faulty, green wire that run along the front x member damaged, coil supressor faulty, you could be chasing the fault forever on mfi.

when you say you tried another ecu did you try a compatible ecu? harts and diamonds will only run on certain types of ecu but cant remember what ones, best trying another hearts and diamonds one

 

Have you checked spring on inside the meaturing unit. I had an s2 with same sort of problem by your description. (overfueling) turned out to be the preload spring on the meaturing unit. get on of your mates to hold the dish up a bit while you try and start it.
could be nothing but is worth a try as will not cost any parts to test.

 

tbh mate as you haven't had the engine etc running in the past i would guess (from you description) that the car is running very rich,

If you pull a vacuum pipe off the inlet and partially block the hole can you get the car to run any better? And what happened when you un plugged the black box like i asked earlier?

Rob,

 

hey there mine was doing the same (overfuelin) it would flood itself on idle. if urs does this try pulling out the fuel pump relay and turn it over see if it starts if it does it must be cuttin out to overfueling mines turned out to be black ecu and the tpc was jammed on full throttle thanks to ava that found that out lol

alan

 

my mates did this after being stood, i changed the injectors and it ran fine, the old injectors looked like they had been rescued from the titanic!!!

 

Does it kick out black smoke? I had a similar problem and turned out to be temp sensor (yellow one on back of inlet)

 

It did kick out a bit of black smoke when i had it running, cant get it to fire up at all again now !

Have had the injectors to check them and the tips seem clean enough, was thinking they might have corroded with the car sitting unused for so long but they look fine.

It didnt run with the fuel pump relay disconnected as tried all sorts with it ! Tried bridging out the relay just in case it was that that was causing the problem, even tried another known good relay and no difference.

Have tired disconnectin each sensor at a time and no difference, thought i had found the problem the other night as found a soldered connection on each of the metering head connectors that had gone blue and corroded, changed the wires but yet again it made no difference !

It wasn't a hearts and diamonds ecu i tried, just a red and blue square one i think, maybe its not compaitable with a 90 spec car is it ??
Are all the injector ecu's the same as its unknown the age of the one that i had as a spare, also unknown the condition of it !

Am thinking the problem is to do with fuel pressure and whatever controls the pressure from the metering head, whether its down to the inj ecu or the injectors themselves or something else i dont know !

 

unplug fuel pressure regulator on back of metering unit.if it it is better ur fuelling needs to be adjusted or cud b yellow sensor on back of inlet broke,an old cabriolet rs i had wudnt run with fuel pressure regulator plugged in,was found that the wires goin to yellow plug had snapped,so it wudnt run wen the pressure regulator was plugged in.rejoined the wires and was fine

 

Rick, ive said that to him twice now with no response, plus he really needs the engine to be warm for this to prove anything.

Rob,

 

where in scotland are you mate i could try give ya a hand?

 

I did mention that i had tried disconnecting various sensors and made no difference ! I wasn't sure what you ment by EMFPA but guessed it was the pressure regulator on the back of the metering head !

I cant get it to run long enough to get the engine warm, it would run for maybe 2 mins at most then die out and wont start again after that, now it wont start at all !

 

Kind offer mate but am quite a few miles away from you !

Im 80 miles west of Inverness !

 

I think you are running stupidly rich, this could be because of a bad sensor input, or because the metering unit is adjusted wrongly...

Other possible causes are injectors and ecu.

Do you own a multimeter?

And finally, with you cranking the car, if someone lightly pushes on the metering flap.... like a few mm, what happens?

Rob,

 

It seems like its mega rich when i was running and only seemed like it was on 4 cylinders when it was getting throttle, try and hold a constant rev and it went pear shaped and ran like a bag o shite ! Would splutter and die out unless you gave it more throttle, this would last for maybe 2 mins then it would eventually conk out and refuse to start again !!

Would faulty injectors cause a lack of pressure coming out of the metering head ?

I was thinking that the problem might have been in the metering head itself or the injection ecu (the car didnt have one fitted when i bought it and the one i have currently fitted is unknown as was in with a load of parts i bought for the car).

I will try lightly pushing down on the flap when cranking, what should be happening when i try that and what multi-meter checks can i carry out ?

Really keen to try and get this sorted now as have already missed out on a couple of events i should have been taking part in with the car !