Enki
Motorhead
My lean burn cruise tune would like to have a word.
40% is enough to make full boost.
[SOLVED] No power, enters limp mode on acceleration
- Thread starter chris' speed 3
- Start date
- Watchers 10
chris' speed 3
Greenie Member
Im not slamming onto the throttle It has to be gradual or it misses, the issue is directly correlated with calculated load, starts at 0.65 calculated load
So low to mid 15s are "safe" for just cruising? Good to know but I am too worried about screwing something up to do that haha
I agree it seems it has to be a tune/electrical issue of sorts.
chris' speed 3
Greenie Member
Not tune related according to Justin but maybe he's wrong who knows.
Im not a mechanic so its possible I missed something or didn't check something properly, ill tell the guys at the garage what I've done so far and what exactly the issue is and hopefully they'll be able to figure it out!! Then ill let you guys know what the problem was being caused by
Enki
Motorhead
Been doing this for years, even on my old engine. There's a thread on it here somewhere I think.
It's best if they start from scratch, to doublecheck everything.
At this point I'm guessing this is why the car was sold off by the prior owner in the first place.
chris' speed 3
Greenie Member
Ill just tell them ive changed spark plugs and replaced the cat also tested a different MAF
Also I don't see why this issue would be the reason the PO would of sold it as its the first time this happened and it happened after 7k km of me driving it
chris' speed 3
Greenie Member
Mechanic texted me today he asked if he could get a new ignition coil for number 4, so he thinks its an ignition coil. Ill let you guys know next week if he was right
Enki
Motorhead
Been thinking about this, and it seems like coils *could* be an issue and I thought one of the suggestions I made was to swap coils with another car and see if it persists but it seems like I did not. Odd that it would idle and cruise fine but fail to fire even under moderate loading; this would be the first time I've heard of such a thing at least.
chris' speed 3
Greenie Member
Well still gotta see if the coil actually does fix it, If i didn't get the appointment for today I was going to meet up with the speed that I swapped MAFs with and swap coils
It would be awesome if it's just coils after thinking my engine was done for the last couple weeks
When you first gave us low compression numbers it seemed like that was the case. I suggested a leak down test to verify that everything is sealing as it should.
I'm not sure how one coil could cause intermittent breaking up under load. Unless there is a power or ground wire with high resistance. At lower loads (idle, cruise) the coil dwell is a little longer cause it doesn't fire as fast. When you're going ham on the throttle the ECU has to fire that coil pack as quick as possible since the load is so high.
If the wire can carry enough current to allow the coil to dwell enough it wouldn't be noticable but during extreme conditions it would be hard for the coil to get a hot enough spark through the combustion process.
That's just my guess as to a logical reason why a coil wouldn't fire well under high loads.
I'm not sure how one coil could cause intermittent breaking up under load. Unless there is a power or ground wire with high resistance. At lower loads (idle, cruise) the coil dwell is a little longer cause it doesn't fire as fast. When you're going ham on the throttle the ECU has to fire that coil pack as quick as possible since the load is so high.
If the wire can carry enough current to allow the coil to dwell enough it wouldn't be noticable but during extreme conditions it would be hard for the coil to get a hot enough spark through the combustion process.
That's just my guess as to a logical reason why a coil wouldn't fire well under high loads.
chris' speed 3
Greenie Member
My compression tester is junk, as it gave my inconsistent readings so that's my bad for the numbers. As for the coil, that's pretty much what i've been thinking for the last couple weeks something to do w the spark getting weaker under load
I should know monday if the coil fixes the problem or not
What @Enki was saying was to swap coils to a different cylinder and if the misfire moved then you'd know it's a bad coil. If the misfire didn't move you'd have to look at the wiring to the coil or something else.
chris' speed 3
Greenie Member
Well my cars at the garage now so too late for that, I bought a cheap scanner that would show me individual misfires and it said 2,3 were missing but the garage said its cylinder 4 so im returning that scanner.
Don't return the scanner. Keep it. You'll never know when you need one again.
chris' speed 3
Greenie Member
It didn't work properly, Im going to order a better one
Enki
Motorhead
You don't know this for sure yet.
Well dang hopefully that's all it is man! Glad you got it in the shop though so let us know! I bought off brand coils and they have worked perfectly fine so maybe I just got lucky haha
Any updates from the shop?
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