Mfi 1.6T misfires under boost
Hey all,
I have an escort rs cvh 1.6 mfi thats starts like a charm. But when i accelerate and make more boost then -0.5 (on my boost gauge) it misfires and splutters a bunch. When i ease her into the rpm's she will go beyond 3k but she doesn't like it. But, when she is cold she picks up fine and only has a slight misfire. Now i thought of it being an vacuum leak, but when i manually press down the metering flap it still misfires. It will rev out when not in gear but the initial pickup is spluttery.
Replaced items:
BobinePlugs and leads (not the lead from the bobine to the distributor)
InjectorsFuel distributor
I know of one injector rubber being ripped half way and i'm getting that replaced. But i dont think that small leak could cause such problems.
Anyone have any ideas?
I have an escort rs cvh 1.6 mfi thats starts like a charm. But when i accelerate and make more boost then -0.5 (on my boost gauge) it misfires and splutters a bunch. When i ease her into the rpm's she will go beyond 3k but she doesn't like it. But, when she is cold she picks up fine and only has a slight misfire. Now i thought of it being an vacuum leak, but when i manually press down the metering flap it still misfires. It will rev out when not in gear but the initial pickup is spluttery.
Replaced items:
BobinePlugs and leads (not the lead from the bobine to the distributor)
InjectorsFuel distributor
I know of one injector rubber being ripped half way and i'm getting that replaced. But i dont think that small leak could cause such problems.
Anyone have any ideas?
Few things to check if not allready, all Turbo Hoses / intercooler etc no leaks....Manifold gaskets !!!....it sounds like its "leaning out" re - low fuel pressure....as you say some what better when Cold....then from Cold the pressure will be Higher via the "Pressure actuator"....but that resets itself after a 1/2 mile or so...depending on temperature, the Bosch KE runs very High pressure 80/90 psi... has it been checked ?....is the Fuel filter known to you been changed, Im thinking your ignition OK, but you can get HT testers that go on the spark plug and "Glow" when running...so one can see the Spark ok when you increase the rpm..sure you know this...but just a mention, you can allways tell when the Fuel pumps are getting old / worn buy the noise they make...should be a nice "hum".. not rattly / noisy if low pressure then your exact fault. , also ensure when engine running there is 12.8 / 13volt at pump itself....as these cars age not uncommon low volts, more so if the "Fuse-able links" are still on the battery...most thrown away years ago. just a few helpers...as said "Pressure actuator" is a clue . Peter
Few things to check if not allready, all Turbo Hoses / intercooler etc no leaks....Manifold gaskets !!!....it sounds like its "leaning out" re - low fuel pressure....as you say some what better when Cold....then from Cold the pressure will be Higher via the "Pressure actuator"....but that resets itself after a 1/2 mile or so...depending on temperature, the Bosch KE runs very High pressure 80/90 psi... has it been checked ?....is the Fuel filter known to you been changed, Im thinking your ignition OK, but you can get HT testers that go on the spark plug and "Glow" when running...so one can see the Spark ok when you increase the rpm..sure you know this...but just a mention, you can allways tell when the Fuel pumps are getting old / worn buy the noise they make...should be a nice "hum".. not rattly / noisy if low pressure then your exact fault. , also ensure when engine running there is 12.8 / 13volt at pump itself....as these cars age not uncommon low volts, more so if the "Fuse-able links" are still on the battery...most thrown away years ago. just a few helpers...as said "Pressure actuator" is a clue . Peter
So I checked everything except for fuel pressure, and everything was fine, injectors pushed out fuel like a boss. Filter is 6k km's new and al gaskets are fine. So I looked at my dizzy cap and when I took it off there were a few plastic parts that fell off. I put it back on and she didn't fire up again because there was no more spark (the connector was bodged on) So I put a multimeter on the + and - cause it should put out around 2.4/4.8 volts according to this forum post: https://passionford.com/forum/ford-e...ct-sensor.html. Now I am thinking that this could be the problem, because maybe the on boost timing couldn't be correctly put out. This could also explain why it ran okay when ice cold, if the sensor was already shot the extra heat doesn't do it justice. I think this will be it, either way I have to replace it now. Thanks for the advice.
The "Hall effect" ignition system used, the 3 Pin plug at Distributor,,,1 Red/black tracer is indeed with ignition on 4.5 to 5 volt....2nd wire Brown is common - earth......3rd wire Green/yellow tracer....is the signal back to the "Silver ECU" where the internal Amplifier converts to " neg " pulse for Coil & rev counter, take it the pick up in Distributor is damaged. Peter
Last edited by OAP Pete; Aug 31, 2021 at 06:08 PM.
So i found a new Hall sensor and this reads correctly. But she still won't even start now. There isnt a spark and It doesn't fire any injector when i take them out. My coil gets 9V, my fuel pump pressurizes, no fuse is blown and all relays work as far as i know. So i am bedazzled, anyone have any ideas?
I think it could be the pump, it sounds different so i will check that. Does the system know when there isn't enough fuel pressure? Cause i cannot for the life of me get it to spark.
I think it could be the pump, it sounds different so i will check that. Does the system know when there isn't enough fuel pressure? Cause i cannot for the life of me get it to spark.
Last edited by Mitchel Jonckheere; Sep 7, 2021 at 03:38 PM.
You must consetrate on the HT spark issue , before thinking about Fuel system....hear is how to test for a spark...you might check the "Gap in the Trigger plate", as you have had the distriburor out etc....might have disturbed the "Gap "....you will see 4 Gaps in the round plate, make sure the Gap in the plate is 20 thou as it passess the sensor....you should have 12v at the Black wire on ignition coil....ok turn on ignition unplug the 3 wire plug...rig up a Test lamp...ie 6 watt bulb be fine , connect one wire to earth [ ground ]...remove King lead from distributor...place near the engine block...touch " off & on " the other wire from your Test lamp to the " green / yellow wire" only in plug, coil will activate a strong spark. ok...if not ....but i feel it will be ok. then fault in distributor. Peter
Last edited by OAP Pete; Sep 7, 2021 at 06:02 PM. Reason: not finished
You must consetrate on the HT spark issue , before thinking about Fuel system....hear is how to test for a spark...you might check the "Gap in the Trigger plate", as you have had the distriburor out etc....might have disturbed the "Gap "....you will see 4 Gaps in the round plate, make sure the Gap in the plate is 20 thou as it passess the sensor....you should have 12v at the Black wire on ignition coil....ok turn on ignition unplug the 3 wire plug...rig up a Test lamp...ie 6 watt bulb be fine , connect one wire to earth [ ground ]...remove King lead from distributor...placw near the engine block...touch " off & on " the other wire from your Test lamp to the "
Thanks in advance,
Mitchel
Trending Topics
Your getting confused...the Ignition coil has 2 wires...one Black which is live 12volt on turning on the Key...the Green is the Trigger from the silver ECU..dont test with meter that wire..no need at moment...so doing my test on the "green / yellow" wire the amplifier in the silver ECU with send a "negative pulse" to the coil...OK Peter
Your getting confused...the Ignition coil has 2 wires...one Black which is live 12volt on turning on the Key...the Green is the Trigger from the silver ECU..dont test with meter that wire..no need at moment...so doing my test on the "green / yellow" wire the amplifier in the silver ECU with send a "negative pulse" to the coil...OK Peter
NO Ballast coil not used on RS Turbo series 1 or 2...!!!...will effect the output of the coil you have if its being used, with eventual damage to the ECU..... as the wiring loom is not set - up for a ballst coil...but with my TEST will make a ballast coil give "HT SPARK"..but just as a check as the ECU amplifier within wont like it...so as a test...OK only..the proper coil was a Bosch unit with a amps draw with the coil "neg " to ground was 8/9 amps as a test only. Peter
So my distributor switches on the "0" pin from 2.4 to +-4.8v, is this correct? If this is correct the only suspect left is the ECU right? I can't do anything to get my green wire to connect to ground.
Also I tried putting my test lamp on the green wire of the coil and the other side to an earth point, still no juice.
Kind regards,
Mitchel
Also I tried putting my test lamp on the green wire of the coil and the other side to an earth point, still no juice.
Kind regards,
Mitchel
Last edited by Mitchel Jonckheere; Sep 10, 2021 at 03:27 PM. Reason: More info
Your following not my test procedure...i realise now [ sorry ] you may not be in this country or the car ?....all i can do is write the Test again, First can you make sure you DONT have a imobiliser fitted !!! in case blocking the "Black " wire on coil....also that Black wire splits off within the loom to 2 outher locations...1 the fuel pump relay....2 the Silver ECU pin 13. So to test the Hall effect system used on RS Turbo, Coil test fit H/T lead to coil.....the other end close to engine block...turn on ignition the Black must be live 12v....if not..STOP there is a major problem...i come back to is imobilise fitted ????...Will continue assuming there is 12v...pull off the green wire, your going to need a "old school condensor" really to see a strong HT spark, get a clip lead to earth [ with condensor in paralel if available ] touch the earth wire off & on to coil neg terminal...HT will be good...but weaker if no condenser, all good !!...spark there, now ignition still on reconnect green wire...unplug the distributor 3 wire plug...first make sure 4/5 volt is on the "Black/red terminal"....make sure the "Brown" wire is earth...now with a good Test lamp 4/6 watts to earth...with the probe of the Test lamp off & on to the Green/yellow terminal...you are now testing the ECU amplifier good spark ok...all being well ECU fine...pick-up in distributor faulty. best i can explain my end , if you have a friend your end with knowledge of cars, should understand Test...remember no "Black circuits " will never run...imobiliser / alarms to be looked into ?.. best i can help this end..... Peter
Last edited by OAP Pete; Sep 11, 2021 at 06:50 AM.
She started out of nowhere
i drove for a bit
stalled
road services came to help
he did your test and now i understand it
it is still my hall sensor
thanks for all the help everybody!
Mitchel
i drove for a bit
stalled
road services came to help
he did your test and now i understand it
it is still my hall sensor
thanks for all the help everybody!
Mitchel
Last edited by Mitchel Jonckheere; Sep 11, 2021 at 03:02 PM.
never had a ECU give trouble...make sure you have live 12v at the ECU on pin 13...open up the loom to see the "Black" wire...thats ignition live same as Fuel pump relay number 15...there are no external "Blade type fuses" on this circuit, But the main power at ignition switch heavy Red wire is protected buy the original [ if still fitted ] Fuseable links on the battery "Positive post "....pulling off the green wire on coil..ignition on, you will see 12v at the coil "neg "....the green wire ends up in the ECU amp, something not right,.....make sure pin 2 of the ECU brown wire is earth...as thats the common earth for the entire ECU and its components.... as said you can open up the loom plug.....see the wiring to do checks.....trying my best this end.
Thread
Thread Starter
Forum
Replies
Last Post







