Skipping when lightly on throttle.

[Zelfear]

My N/a is skipping when I am lightly on the throttle. like when you are just tring to keep a constant speed. Some times the idle fluctuates other times its normal. when it flutuates the valve by the cold start opens and closes. Any ideas?

I have replaced the spark plugs, wires, cap, and rotor button about 1k miles ago. I used E3 spark plugs, bosch wires, the autozone brand rotor and cap. Someone told me to check my spark plugs. Also there were a bunch of bubbles in my coolant that looked like white foam is this an issue? I didnt see any oil in there. I'm going to check timing and compression today.

 

[ricerkid]

it sounds like a bhg from the bubbles in your coolant. is your coolant really dirty?

 

[Zelfear]

no its not dirty at all. The bubbles are really tiny it looks more like a foam than bubbles though. Im not losing any coolant either. I'll see if I can get a picture.

 

[ricerkid]

is your overflow tank dirty inside? my coolant doesn't look that dirty, but my overflow tank has oil and exhaust gas residue in it so that's how i knew i had a bhg. I cleaned the tank when i got the car and a week later it was dirty again... also, your afm might be messed up since the idle fluctuates. i replaced the afm and it fixed my idling problem and my revving problem. sorry if my info isn't that helpful... i just started working on cars.

 

[Zelfear]

Ok here is a picture of the spark plugs and coolant.

 

[Zelfear]

Also I did a compression test to the number 1 cyclinder and it was 195 I'll check the rest later when I have time.

 

[radiod]

195psi seems super high on the compression. TSRM says 156psi (or higher) for the GE. Has the engine been rebuilt, head gasket replaced, etc before? If so someone may not have done their homework and put too thin a gasket on to keep your compression in check. If that's the case, I wouldn't be suprised if you've got a break in your headgasket in one of the other cylinders.

Take a look for the obvious signs...gurgling waterfal noises when reving cold, white smoke on startup, rough idle on cold start, milky oil cap after a lengthy drive (short drive doesn't work...that's just condensation), oil in the coolant resevoir (look for the little rainbows), overheating, etc.

 

[AJ'S 88NA]

Have you checked and set your TPS lately, could be the "skipping" problem. The foam, have you used a coolant flush lately, that's what it looks like to me.

 

[Zelfear]

195psi seems super high on the compression. TSRM says 156psi (or higher) for the GE. Has the engine been rebuilt, head gasket replaced, etc before? If so someone may not have done their homework and put too thin a gasket on to keep your compression in check. If that's the case, I wouldn't be suprised if you've got a break in your headgasket in one of the other cylinders.

Take a look for the obvious signs...gurgling waterfal noises when reving cold, white smoke on startup, rough idle on cold start, milky oil cap after a lengthy drive (short drive doesn't work...that's just condensation), oil in the coolant resevoir (look for the little rainbows), overheating, etc.

Well I got the motor from a junkyard about a month ago and the car had 140k on it. I check the head bolts and the were already torqued to 72ft-lbs so Im pretty sure it was replaced.

I don't see any of those signs. could the higher compression foul out the spark plugs? They seem to have a little too much carbon on it for only being in there 1000 miles.

Have you checked and set your TPS lately, could be the "skipping" problem. The foam, have you used a coolant flush lately, that's what it looks like to me.

No I haven't. how would I check and set it?

Well I put the motor in about a month ago and when I did that I used some purple power to clean out the radiator. I think that is what the "foam" is. My dad said something about that earlier tonight.

 

[AJ'S 88NA]

http://cygnusx1.net/Supra/Library/TSRM/MK3/ Should tell you all you need to know.

I'd flush the coolant system and refresh it with new.

 

[Sideways_bob]

I was getting the tps code and mine was doing it as well.

It runs fine but only does it when cruising at a constant speed. it jerks pretty rough and the rpms go wild until I press in the clutch, and let it back out.

 

[gelboy1015]

Mine has been doing the same thing going over 50 mph. Runs fines, but jerks while gaining speed after 50. Changed my AFM yesterday, but it still does the same thing. Ill look into changing my TPS..

 

[AJ'S 88NA]

Did you guys set it according to the TSRM?

 

[BlackDynamite]

Mine will slightly sputter/ backfire when cold.(No cat, timing 14 degrees, and upped compression by a shit ton) Mine is a auto to manual, still running auto ecu and wiring harness. So technically it is always in park LOLZ. Sounds like tps, and why the hell is ur coolant white!? Milk is not a coolant...

 

[Zelfear]

Well My problem ended up being my spark plugs cleaned them up and ran fine afterward. The white coolant is just bubbles which we figured out was from some purplepower left in the radiator from when I used it to clean it before putting it in.

 

[BlackDynamite]

well, if the plugs are fowling out that quickly, check your valve covers. they tend to leak because of the crappy Philips screw heads. can't torque them enough and they'll strip. hit up home depot, lowes, etc. and get the same thread and length. cost you like 4 bucks. worth it.

 

[shaeff]

Well I got the motor from a junkyard about a month ago and the car had 140k on it. I check the head bolts and the were already torqued to 72ft-lbs so Im pretty sure it was replaced.

How did you check? Hopefully not by just putting a torque wrench on them and cranking them down. You MUST loosen the head bolts before retorquing them. Just a little bit, otherwise you will not have enough torque to overcome the tightened bolts, even if they're only at 52ft lbs.

well, if the plugs are fowling out that quickly, check your valve covers. they tend to leak because of the crappy Philips screw heads. can't torque them enough and they'll strip. hit up home depot, lowes, etc. and get the same thread and length. cost you like 4 bucks. worth it.

Keep in mind that they're not supposed to be THAT tight. The torque spec for them is 22in lb.

If you get hex head bolts for them, do NOT overtighten them, you could warp the cam cover, or break the tabs right off.

 

[BlackDynamite]

Keep in mind that they're not supposed to be THAT tight. The torque spec for them is 22in lb.

If you get hex head bolts for them, do NOT overtighten them, you could warp the cam cover, or break the tabs right off.

This is true, i just did a zig zag pattern like you do on the head bolts and i had new valve cover gaskets, and rubber washers. Cleaned the covers and head, then I just tightened them until they were tight. I could move my valve covers around with the Philips heads, because they were stripped and wouldn't tighten all the way...so anything is better than that ;]