4age slightly down on power and hesitating in lower rpm

[Sprinter Freak]

Car - KE70

motor / part in question - 4age

problem - low on power, feels doughy and hesitant in low rpm

occurs/started when (if applicable)- in low rpm below 3500

hey guys

Was driving the car home from work the other day, and progressively throughout the drive it began feeling a little dough and hesitant in the low end. it also feels like it hasn't got 100% power, more like 75%-85%. At idle its a little lumpy, but not massively. i've changed the plugs, and it hasn't done anything. i feels as if its not running on all cylinders cylinders.

I tried the trick of taking each spark plugs lead off to see how it changed the running of the engine. The first one(closest to the rad) was fine, as soon as i took it off the engine started to die. The second one seemed like it only affected the running of the engine a little bit, and got only slightly better when i put it back on. The third one was similar to the second cylinder but a little. when i took the fourth plug off it was the same as cylinder one.

Tried the head gasket leak test where it checks for exhaust gasses in the radiator system. But that didn't come up with anything. I have a feeling that it might be a break in the head gasket in between cylinders 2 and 3, am going to get it compression tested tomorrow.

Can you guys think of anything else it might be? i know its got spark to each of the cylinder and it seems to be getting fuel fine.

any help is much appreciated guys

cheers

Ryan

[Gunner]

I think its a good excuse to get some more horsepower but i think youve hit the nail on the head with the head gasket. But could be a host of things. See what the comp test says

[tottacrolla]

Assuming the car is an AE86...........
It could be any number of things wrong but a diagnostic test will help to eliminate some of them.

[Matt]

Check the injector plugs are on properly... Do you need a comp tester Ryan? Can also lend a leak down one as well.

[Sprinter Freak]

yea could be man, if it is the gasket i'm going to get cams, quads and an ecu put in while i'm at it . yea well see tomorrow after the comp test.


yea sorry should have said the car is a KE70 with a 16v bigport 4age in it. yea will run a diagnostic test tomorrow if the comp test comes up with nothing.

yea checked all the injector plugs were on correctly(also pulled each one off while it was running to see there wasn't a break in the injector wires). nah should be good for the comp test, am just going to take the car to the workshop up the road and get them to test it. did the leak test today and didn't show up anything.

cheers anyway man.

[FoldKing86]

Do the usual test like comp, timing, tps, earth, battery/alt charge.

Could fuel quality be an issue. I usually pull the timing back alittle, if things improve, drop fuel and get some more, or just use octane boost and return timing to where it was.

[Matt]

Leak down tests valve stems and cyclinder leakage... Nothing to do with radiator...

[ezyslider]

hi , Ryan sounds like you have a vacum leak , check your vacum line from your map sensor to manifold etc possible leak , would cause incorrect map signal and running rich, also check the vacum line that goes to the fuel pressure regulator . good luck.

[Gunner]

Would everyone stop trying to help him fix it, we need to tell him its fucked, he neeeds something some more power lmao

[Futo_gt86]

Does it have TVIS?
Are all the lines on?