Megasquirt help needed

ok im fed up with reading a manual thats just so full of nonsense and doesnt really apply to my setup

ive posted on msefi and no one really seems to know whats going on with my setup (its not chevvy running eddis)

its a 20vt in a mk1

starts but sounds like the timings out as it holds the starter back at certain points in its cycle once it is running it will idle ok then it gets warm and game over missfires backfires hunts like a blood hound

ive tried every wiring combination as far as the injectors go my fuel gets hot well my fuel filter is warm to touch but both pumps work my wideband reads good

if i try and put any load on the engine its awful so lets start with the timing

my spark map is shady to say the least not an expert in that department yet
trigger angle 83deg

trig a 5
return 14
trig b 35
return 44

set with a timing light

anyone out there want to do a home visit

 

I,ve heard very good things about T.I.M. Sport and megasquirt. Not sure if he is on here. If not then try rajmirch @ SRT on edition38, he will be able to put you in contact

 

Fuel warming up is fairly normal if you're just idling, most of it will be getting returned by the fpr so it'll be doing circles around the fuel circuit.

Are you using the 20v coil packs? Are they wired up correctly and in the right order? I've heard of similar symptoms from people who have got the packs the wrong way round on wasted spark.

 

Hello there, where abouts do u live??

Rite, I had the same problem as you during cranking, it kept holding the starter back and even startin but spinning the engine back and causing it to back fire. I found out what my problem was, but mines a 16V with a dizzy. I expect u wont be using a dizzy rite? Do you have wasted spark setup? Are you picking up using a crack sensor?

If you are on msn, add me and I will try and help.
mrgrr666@hotmail.com

Danny

 

Bens Cab I shall try and talk to Tim this weekend, as has already been mentioned check the coil pack wireing, we had a similar prob on a mk2 with Emerald, turns out the diagram Emerald did for us was wrong, was so long ago that I had forgotten about it till Martyn mentioned it

 

hmm

its running wasted spark 1&4 to spark 2&3 to spark b


all the wiring seems to be ok im going to double check the coilpacks tonight
vr sensor gives a good steady signal

the only thing i did wonder was my triggers with the timing light it reads spot on fixed angle 14deg

83deg angle

triga 5
return 14
trigb 35
return 44

is it worth trying time based timing and 0 the return triggers ??

at a guess i would say i have a timing issue but not ruling out fuel as it could cause the same symptons

using agu 3 pin coilpacks

live in sunny bognor regis

 

timing

just tell me i got this right

original firing order 1342
A B
wasted spark my connections are 1&4 2&3 is that right as thats how its wired

injectors are wired 1&3 2&4 4 squirts alternating

 

Sounds OK, you could try swapping over the HT leads between the two pairs of towers (i.e. swap 1 and 4 for 2 and 3) just to double triple check the coilpack is wired the right way round

 

coils

the coils are hard wired to the ecu dont have plug leads

ok so does the fuel pump relay effect things im using the all the k-jet fuels pumps accumilator ect with a digifant filter then the 20vt fuel pump relay it all works as it should turn ignition on pumps sound then go off

start cranking pumps come on and stay on so i think thats ok

all my wiring seems ok

just runs lumpy as ****

im convinced its got something to do with my triggers is it ok to use time based and 0 the return triggers what effect would that have???

 

hmm spark plugs

ok this is a good idea going to swap my plugs for a set i know work offmy mates pea greem mk1

cos just had horrible thought that it could be a plug breaking down if it is ill buy everyone a pint (if i ever meet you guys )

you lot have been more help that the guy that built the ecu and msefi forum

cheers to you all

ill let you know how i get on

 

plugs

just taken the plugs out apart from being black as black gets once cleaned they look ok
not going to put them back in until ive tried a defo good set guessing most of the black on there is from it was running rich last week or could that have burned off already?

coil packs all look good no hair line cracks ect ect

 

I think I might have noticed something that wont work there, try putting it on 2 squirts alternating . For my LPG setup I needed to run 4 squirts per cycle alternating but I found that the car ran totally rubbish until it warmed up, then it went ok. I reported the problem on the megasquirt form but no one seemed interested as 4 squirts per cycle isnt something many people run. It made the car really rich at when cold, so if you are setting ur mixture from cold I would expect it to go really lean once it warms up, dunno if this could be ur problem.

What version of software are you using?

 

hmm

software msnxtra 029q2

right change plugs no better then had it at idle and it dropped to 2 or 3 cylinders??

check plugs coilpacks all ok

opened up megasquirt and found a wire on on of the vb921s had come of weird
soldered it back on back on all 4 cylinders idles ok slight miss not as bad as before

tried to put some load on it bit better but not great thinking i just need to go through my settings and double check it all before i go any further

could i have a weak vb921?? perhaps its getting to hot ?


once i get my odle nice im going to drive with auto tune see if that helps im still convinced its my timing it loves being advanced tick over 14deg but wants more could it be im dumoing to much fuel in there 12 to 13 afr any leaner and it starts to die

 

just an after thought my injectors are the standard 20vt ones ive set them in the constants as hi impedance

i did try to measure the resistance but my multi meter is shagged it was telling me my battery was 19volts no no no no


so im guessing they are hi impedance

any thoughts on this

 

Have you tried changing the number of squirts per cycle yet? I really suggest you try it because if I set my car to 4 squirts alternating it will idle but die soon as I try to set off.

If anyone else on here is running alternating injection, just try 4 squirts per cycle alternating when starting from cold and see what happens. I would be interested to see if other found what I did.

If your injectors were low impedance they would still work ok set as high impedance, but there is a good chance you mite burn them out once you go for a drive and make them stay open for longer periods of time.

Danny

 

hmm

ive tried 2 squirt similtaniuos it ran like crap 2 squirts alternating seems like alot of fuel to be dumping in there

4 squirts alternating is the best so far

going to try and get all my settings checked in the morning what could make it hunt on idle its like its missing a beat every now and then

not to worried about driving it yet i think that will sort its self out with auto tune if i can get it to idle im half way there

 

I run 2 squirts alternating, if you run 4 the idle PW will be havled and you`ll need the opening times etc spot on or you`ll have to re-tune, may never get a reasonable idle, plus due to the injectors been closed more often you may run into DutyCycle problems at full load/rpm.

 

msns

my pulse width at idle is 2.1 ish is i go 2 squirts my required fuel goes from

13.0
6.2

to

13.0
13.0
is that to much fuel ??

how are yor injectors wired to ms i have 1and3 to bank 1 2and4 to bank2

 

That injector arrangement should be fine, your required fuel is doubled because you are doing half as much injecting. Your injectors are opening half as much, so they need to open twice as long.

Keith, when I ran 4 squirts per cycle alternating because it was for my LPG setup because its more like throttle body injection rather than each injector having its own port. I found that on both fuels it would not run correctly when cold, the accel enrichment were miles to high(had to almost turn them off), if I got it running ok just reving it, soon as I set off it would go really rich. Yet if I let the car idle for 5 mins to warm up, it ran perfect on both fuels. I believe there is a fault in the code somewhere to be honest.

Danny

 

hmm

going to try 2 squirts alternating tommorow i think ive tried it before and it flooded the car up but hey ill try anythink at the moment

i even had mickey marrows from edition 38 come round and have a go he said rewire my injectors which i have then start driving it once your idle is sorted he managed to get it to idle but had to create an air leak to do so

hes been a star helped me out so much just want to get it to the point where i can drive it with autotune

i seeled the air leak back up and made some adjustment to get it to idle so i think ive got it as good as he had it