Need some help with All Trac Celica

[Acro]

I'm hoping the turbo guys can help us with this. A really close friend of mine just bought an 88 Celica All Trac Turbo. He's having issues with hesitation under boost. I just got off messenger with him and this is what he described..

"Under boost the car is hesitating bad. its like there is no power at all. Also....the only way i can describe the slight bucking is...like the clutch is slipping and grabbing alot, but thats not it because the clutch is brand new. This only occurs under boost. normal driving is fine."

Any ideas on what may be going on? Any help would be greatly appreciated.

[MeFryRice]

It could be numerous things.


Mis-firing
vacuum leak


etc....

Any CEL's?

[Acro]

Nope. No CEL's that he knows of.

[Jack-MX5ATLanta.com]

Was it working properly at any point? Casey's old 240 was like what you're describing but that was partly due to bad fuel pump and lack of a tune. Has he changed anything recently? Could easily be a vacuum leak.

[MeFryRice]

when I had my old MR2, I Was getting on it on night when all of a sudden, my boost gauge was reading no boost, all vacuum. It ended but being just the boost pressure hose had popped off.

[Jack-MX5ATLanta.com]

The joy of turbo cars :rolleyes:

[Acro]

It was running perfect when he bought it a few weeks ago. He's done nothing to it yet. I'm constantly sending him all the info I get from you guys.

[Acro]

The car was working fine when he got it a few weeks ago. It just started this a couple days ago. I'm sending all the info I get from here to him. He's a really good friend, and I wanna help him all I can.

[FGFennec]

Hey all, I grabbed an account on here to get better info about my All Trac. Thanks to Acro, he made a good post about it. I figured I would post up the mods as well, maybe give someone a better idea about whats going on.

Upgraded CT26 Hybrid Turbo, Stage 1 Clutch, Koyo Radiator, Walboro Fuel Pump, A/C Delete, Charcoal Canister Delete, EGR Delete.

* no tune, stock boost at 5 lbs.

[Jack-MX5ATLanta.com]

Cool welcome aboard, be sure to post up in the intro thread. Hopefully one of the resident boost addicts here can help out.

[Acro]

Heya Fen :3 Good to have ya' onboard. Great group of people on here. I didn't know all the mods done to the car :p

[FGFennec]

I feel so...huge in my cars here....all these tiny little miatas running around...being SO MUCH FASTER THAN ME...

[Acro]

I feel so...huge in my cars here....all these tiny little miatas running around...being SO MUCH FASTER THAN ME...


But you are much faster on dirt :p Granted..I did some rally style powerslides last night :p

[wantboost]

do those cars have a mafs, if so check that? that or a vacuum leak would be a good place to start.

[FGFennec]

Yeah it does, the flappy thing on the intake. Yeah, the most popular answer for what im having is a vac leak somewhere, I also have a high idle which can also be explained by that.


do those cars have a mafs, if so check that? that or a vacuum leak would be a good place to start.

[wantboost]

when my car did something similar to what you are describing it was the mafs

[FGFennec]

Most people are suggesting the vac leak...the MAF is angled down a bit, so i propped it up, it didnt fix the issue, not sure whatelse i can do in this situation regarding the MAF. Sick Silvia tho ^_^

[RotorNutFD3S]

Common cause of this problem for us is spark plugs and/or the gap. Are you running stock plugs? May want to consider going a step colder. For example, Miata's stock plugs are BKR5E-11, a step colder would be BKR6E. I run BKR7E since I run higher boost than most. Now, these are NGK V-power plugs, the model number will vary among manufacturer's.
What are you gapping the plugs at? I keep mine between 0.035" and 0.040", any more than that and the spark gets blown out. Try setting all of them at 0.030" and see where that gets you. And if the plugs look trashed, replace them first! :)

[FGFennec]

I was informed that they replaced the plugs, no so much the wires tho. They didnt exactly tell me what kinda plugs or the gap on them. However they did mention that they were cooler burning than longer lasting plugs. Im not sure what that meant as they didnt go into detail about it. I will take a look into this however as it might be a cheaper and easier alternative...but taking off that top mount IC is gonna be a paaain...

[MeFryRice]

Taking off the top mount IC isn't that hard actually, just time consuming.

stumble/misfire on acceleration = it seems like it jerks and bucks when starting from a stop or accelerating from a lower speed. May not be as noticeable in neutral as when in gear. Typically an ignition misfire when it is not limited to a certain rpm. Do the ignition/spark system basic tests. If it always seems like it happens at the same rpm's then check the throttle position or map/afm sensors.

Hesitation = it seems like it takes more time for the engine to pull at certain rpms. This can be a result of improper timing or not enough fuel/air delivery. Depending on how long the duration it is in the rpm range or if its at the top or at the bottom will point you in which system to check first. Typically at the bottom of the rpm range you should be checking: tps, afm/map, timing, vacuum leaks. In the middle rpm range: tps, afm/map, timing, egr. At the upper rpm range: tps, afm/map, timing, egr, fuel.

Lack of power = when you step on the pedal and it seems like the engine doesnt pull like it's suppose to. Check the basics. An engine that pulls slowly at the bottom rpm range and then seems to "pick up" at the top is generally a sign of retarded timing( now is a good time to use that new timing light you just bought). If it seems to start pulling but then just flat lines like it's out of breath, suspect restricted exhaust or lack of fuel. Holding your hand a few inches form the tailpipe while somone revs on the engine, there should be a nice flow. Sometimes removing the O2 sensor from before the catalytic convertor can be enough to make a noticeable change with a plugged cat. A basic fuel system test will determine if you are supplying enough fuel to the rail. Give the spark plugs a good visual to see if they are running lean. Even a partially open EGR valve can return enough exhaust to bog the engine down.

[RotorNutFD3S]

Definitely take a look into the spark system then! That sounds exactly like what I had happening when the gap was too big. Oh, and for your car's sake, make sure they are NOT platinum plugs, those do nothing to help a turbo car.

Oh, and who said owning a fast car would be easy? :P

[FGFennec]

Bahaha....a potentially fast car you mean...currently my camry pulls harder....I can take a look at what i need to do, thanks to some help from you guys here. im gonna replace all the vac. lines with silicone....and then see if it fixes it, also gonna hardwire my fuel pump up permanently....then...check the plugs and wires and all that fun stuff......The plugs are copper i believe.

[MeFryRice]

Welcome to the fun world of the 3S-GTE. :D

[FGFennec]

Bahahaa..its my dream motor, i just wasnt expecting issues right out of the box...the car has so low miles too!!! 87k!

[RotorNutFD3S]

I was trying to give it some credit. lol

I've used NGK V-Powers on every car I've had, 4 of them boosted. They simply work the best for what they are and are not too expensive. I highly recommend a swap. :)

[FGFennec]

Hmmm i think my friend had some NGK plugs....they were randomly citrus scented..haha...thats the only way i remember them.....they were some crazy iriduim plug...

[FGFennec]

OK!!!! So, i took some time and really looked over things today, bought some new vac hose just in case...i capped off my T-VSV, hooked up some random vac lines that were just chilling out...and hooked up a boost gauge...and guess what....IT RUNS FINE NOW!

Also...i found out why the car isnt pulling as hard as i wanted it to....the stock boost is 5LBS....the stock gauge says 8+ so i was expecting something harder pulling....but with the new boost gauge...i can see my vac sits around 22-24...and under full throttle, boost sticks at 5.

[MeFryRice]

That's awesome to hear man! Glad it was something as small as a vacuum leak.

[RotorNutFD3S]

Sweet! Very cool that it was nothing major!