4agze coffs and farts after bit of spirited driving

[mojo_type]

My map gze is coughing and spluttering after a hard run
eg after its up to running temp if i say boot it hard up to ~160kph or so from 0 it goes fine as usual
THEN
try to give it some again after the "power run" so to speak and it coughs and misfires
almost like its not getting fuel
but slowly wind it out and its ok at the top rev range
in 4th at about 60kph put the foot down and it coughs terribly as soon as its on boosts above 5psi

im thinking spark plugs but before i go buy some any other ideas ?
seems to be heat related or after a thrash (thats why i assume heat related)
its fine when its cold or getting up to temp

could it be the coilpacks ?

[caibs]

could be a number of things mate, do your plugs first and if that doesnt solve it look at fuel and ignition problems. could even be something like a stuffed o2 sensor.

[myne]

Map or AFM?

I'd be thinking boost leak if it's AFM.

[mojo_type]

map

yeah only while its hot though

ill change plugs soon and see how it goes

[kassma]

Hey Mojo_Type....

If this is a 4agze Map, it would also have individual coils for spark (IE: 2 coils for 2 spark plugs each, giving total of 4). I would suspect this is where you problem is.

But I would probably go along the lines of 1) Change spark plugs (Cheap), 2) change spark leads (cheap), 3) check injectors, possibly get them cleaned and connectors checked, 4) check your o2 sensor, and 5) check your coils (Very expensive).

I used to have the exact same problem in my supra, and the cause of it was the coils sitting on top of the engine in the 7mgte engine. Sure enough I started with sparks, spark leads, and then coils.

Hope this helps.

MIKE.

[DavisJD]

had similar problems, wasn't running a cooler at the time and was running 11psi so had the timing backed off and it running rich to look after the engine. Mine got so severe sometimes that it would turn off from the heat. The fuel was vapurising. Anyway got a cooler put in and a re-tune as well as change the spark plugs as they were dirty. All was fixed

[xolent]

what car was it before?

was it carb before?

sounds like your killing your petrol after the run, then you go for another run with not that much petrol left, petrol gets surged.

after the "power run", did you notice this happening while just gunning it on the straight or through some twisties?

[phrostbyte]

Could be something as simple as detonation, although the 4AGZE has a knock sensor right? Engine very hot = fuel could be detonating before spark therefore not giving off any power (Ignites as piston is coming up, and tries to force it down on the wrong stroke). You running 98/101 octane??

Kev.

[mojo_type]

thanks for the ideas guys keep em coming

it was a carby 4ace or 4afe cant remember so yer it cuts out when its low around corners but after a power run even if you leave it for a while it coughs n shits so its not a fuel surge problem

ive got top mount intercooler with no hole in the bonnet
ill be gettin a front mount soon so hopefully solve that

engine doesnt get too hot
always sits above normal but ive checked with a laser temp gauge and the gauge is just a bit higher then usual so its not overheating .. i hope

alwasy run bp 98 in it, we dont get that 101 octane shell? stuff in perth :/

be playing with a 1j project soon so i might have to wait to fix it

[ToySprinta]

Mine did the exact thing, because the coil packs were stting on top of the engine and getting hot... moved them to fire-wall and haven't had a problem since. Could be something to look into...

[inertia]

CAS getting too hot maybe?

[oldcorollas]

any ignition or electrical component could be getting hot and wigging out.. i would bet on coils or ignitors as first port of call, but it could be anything... having an interwarmer with closed bonnet probably doesn't help much

[Nim]

it was a carby 4ace or 4afe cant remember so yer it cuts out when its low around corners but after a power run even if you leave it for a while it coughs n shits so its not a fuel surge problem

The 'E' on the end means it has EFI, so it was a 4A-C or 4A-F (4A-FC? Not sure), no E in there.

What car do you have this in? AE86? Try putting a vent on your bonnet to get some cool air into the intercolder.

Are the coil packs under the topmount? If so, this could be whats heating them up. Might be an idea to relocate them to the firewall as has been mentioned. Once again though, vent the topmount and the problem may well fix itself.

Or just don't push the car untill you get the front mount in. Although, from what I've heard, relocating the coil packs to the fire wall might be a good idea anyway (assuming they are above the spark plugs).

[mojo_type]

i might try relocating coil packs and try cleaning all the connections :/

its a ae92 seca hatch

and yeh interwarmer aint helpin but i want to keep it looking like a sleeper so no bonnet vents

when i can lay my hands on a vr4 cooler ill get some airflow going until then spark plugs and leads and if i can afford it the coilpacks maybe(if relocation doesnt work)

[Nim]

If you could just rip the bonnet off, go somewhere private and take it for a bit of a fang, then you could see it it was the interwarmer heating the coil packs up. That might not be feesable though.