Breaking up in boost. Car runs good with timing extremey advanced...

[Bhughes]

Recently bought a 1988 starion. It was boosting 13psi and would bust up around 5k rpm. So first thing I did was drop boost to stock 10psi. Then rerouted the vac adv line to the nipple at the top of the tbi. (I checked the vac adv and it seems to be working properly). Then I noticed it had a 1g maf so I swapped that back to stock. Now my problem is it still breaks up in boost with the timing extremely advanced. But if I set the timing to 10 BTDC. It runs horrible, makes no power, and still misfires.

 

Any ideas?

[87B71Brad]

I'm a newbie but...have you checked the fuel injector leads? I've had two of these cars so far and both of the leads on them had the insulation off the wire and was all corroded and caused trouble.

 

Also when you look at the tbi (driver side) there should be 3 vac. nipples in a row. I believe that the advance should be routed to the very first nipple(one on the left). Or thats how my car is run. I could be wrong.

 

Maybe cut in the fuel? I don't know the factory cut out though. I think that I heard on here that the 1g maf raises the cut, is that true?

 

anyone else??

Edited July 20, 2010 by 87B71Brad

[Indiana]

That vac. adv is dead and it will never see vacuum where you put the hose for it. The reference must be back where it was, the forward most of those in a row. This adv. unit also retards timing under boost all the way up to ~7psi. I'd say you have fouled plugs, leaking injectors and maybe plumbing leaks in your intercooler. ?

[Bhughes]

There is a leak in the tbi assembly. Just put new plugs in. I'll reroute the vac advance. And ordering a tbi rebuild kit.

 

Before I moved the vac adv hose it was plumbed into the farthest right nipple and the car ran worse than where it is now. But I'll move it again to where it's supposed to be and see how it goes. Is the vac adv supposed to see vac at idle? If so should I disconect the hose before setting base timing? That's what I would guess...

[Bhughes]

so i undid the vac adv hose, sucked on it, watched it pull up and hold until i let go. so from what i read the vac adv is good right?

 

then while still unhooked up, i set base timing to 10 deg BTDC. (that is the correct base timing right?)

 

routed the vac line to the most left nipple on the TB.

 

 

 

i didnt really notice any misfires and didnt really bust up, but was the slowest thing iv ever driven ( i DD a 2.2l S10, i know what slow is).

 

its WAY quicker with the timing advanced say maybe 20 degress or so. with only s hick-up at around 5k.

 

suggestions?

 

is there a mechanical advance or something (i think i read something about it while searching)

[conquest707]

id pull the distributer and see if its in there right, if its off a tooth that would explain why it runs well under (presumably) way advanced timing

[Bhughes]

Uh is there a certian reason why a tooth off would matter? Cuz on pretty much any other car as long as the timing is set it doesn't matter which tooth it's on. Edited July 22, 2010 by Bhughes

[Indiana]

It might be the timing chain on the cam gear is off or you have clogged up exhaust or a dead locked up turbo or one that isn't but barely spinning.

 

Pull the hose off the compressor housing and spin the turbo with your finger

 

If it has the stock exhaust your convertors might be clogged up but I'd look at the timing chain before I took to cutting out convertors or removing them for testing.

[Indiana]

Could be the wastegate actuator has the wastegate held open a little bit or it may have fallen off, check that. The wastegate actuator arm will be a little bit to short to reach the pin it hooks on.

[Bhughes]

What are y'all talkin about exhaust and turbo? It's open downpipe and it makes boost fine. Hits 10psi and holds perfect. With the timing at 10 btdc it's slow. With it advanced 20 to 30 degrees it's hauls tail. So I'd guess it be timing or ignition timing (distributer). Iv checked the timing and it appeared to be correct. Is there any marks that the cam gear line up with At tdc? All I read was that the chain links are used to set up the timing (colored links, just like when I built a ka24de)

[Indiana]

Its not impossible to check the cam timing but you'll have to remove the valve cover.

 

Set the crank pulley at the TDC mark and have the cam gear with the dowel pin at the top. Looking at the cam gear bolt, draw an imaginary line from the center of that bolt through the center of the dowel and out the to the teeth on the cam gear, it will intersect in the bottom between the tips of two gear teeth. This makes the chain have one of the rollers in that location. Now look to the tip of the gear tooth that is to the drivers side and mark that. Looking at the two cam tower caps that have the bolt holes for the valve cover, draw another imaginary line through those out to the cam gear. These lines meet each other on an otherwise stock setup meaning stock height block and head.

 

Have you checked the compression? Be a good time to do so and also if you have mechanical rocker arms to check those. If you see rocker arms with rollers on them that's why your car runs like arse unless it has a roller cam and I'd doubt it does. 10psi isn't anything for a stock turbo btw so I'm not sure what you expect from it. At what rpm do you see that 10psi in say 3rd gear?

[Shelby]

seting base timeing is only part of checking and adjusting timeing,, you have NO mechanical advance thats why you are haveing to physicaly advance the timeing in order to get any power,,

 

remove the dist cap,, twist the rotor it should turn and snap back to the base position when you release it,, i'l bet any thing it stays where you move it or don't move at all

 

all it needs is a little tlc and cleaning

[Bhughes]

turns and snaps back perfect, or so it seems. but i also feel the mechanical advance is bad but for a different reason. im getting a feeling the previous owner (who has proved himself to me a cheap, ghetto modder) attempted to recurve the timing by changing the springs and used too stiff of springs therefore not allowing the mechanical advance to work.

 

im actually about to walk outside and pull the dizzy and start pulling it apart (iv been reading the rebuild thread over on the other forums).

 

and yeah i understand that 10 psi on this baby turbo is nothing. but i also understand that with timing advance it doesnt knock and rides out and therefore know that something is wrong with the timing... with the timing advance its maybe a 15 sec car...maybe, when set at 10 degrees its something like a 25 to 30 sec car.

[Bhughes]

brought the dizzy in, pulled it apart. and it appears that everything is good, has one soft and one stronger spring like it should. turns and snaps back like it should, and the vac advance works like it should. but something that caught my attention... theres three post sticking up under all the springs/mechanical adv stuff, with a thing spinning with four thing poking out towards the three post. are the supposed to touch at all? i dont believe they are but im pretty sure there hitting one or two of the three post..

[Technology]

I don't think any of that is supposed to touch inside there. Just make sure it doesn't do that. Vac advance shouldn't see any vacuum at warm idle.

 

Where are you hooking your aftermarket boost gauge to the manifold?

 

The reason for setting the crank at tdc and then putting the distributor in with the marks lined up is that you can have adjustment on both sides of where it should be. Not maxed out in one direction just to be right.

 

Take off your valve cover and check the action on the jet valves with your fingers. They should move easily and smoothly. Also do a compression test to see if your HP is leaking out somewhere. A boost leak test wouldn't be a bad idea. Stock injectors are almost all bad. Get new ones.

[Bhughes]

You guys like to get a little carried away don't yall haha. The car runs amazing with the timing advanced. That's pretty much narrowing it down to timing (mechanical or ignition). If the injectors were s*** or the HG blown why in the world would advancing the timing 30 degrees magically cure that?

 

Iv had cars with bad injectors (leaky ones in the s10). And cars with blown headgaskets (e36 m3, built ka24 240sx, and d16 civic). And none ever showed this symptom.

 

The reluctor poles are touching. And there not supposed to. I'm gona see if I can reset them. Throw it in the car and see how she does. If it's a no go ill pull the valve cover back off and check the cam timing.

[Technology]

You don't like to answer questions do you? Advancing the timing might make it feel like it's going away, but why not just set it to the right spot from the get go? No reason to have your distributor cranked all the way over. And didn't you say you advanced the base timing to 20 or more degrees advanced? If that's true then you have something seriously wrong, or you are using a digital timing light that is set wrong. There should be no corrections or +/- any number of degrees, you read it straight off number 1.

 

You say we get carried away, but you haven't actually fixed the problem yet, right? SO do all that shizz we just said and report back, n00b.

[Bhughes]

you just called me a noob and your the one that suggested buying new injectors...cuz we all know advancing timing 30 degrees cures lack of fuel...

 

ill figure it out when i get home. i bet its cam timing or a ******** dizzy.

[Shelby]

yes all of our cars will run like a strip'd ape if the timeing was advance'd but why is the dist retarding the timeing,, it does so because to be safe it has to retard the timeing or knock will happen,,

 

one simple thing such as unpluging the vacuum adv hose will make the car feel like a diff car and run like a rocket,,but it won't for long

 

it sounds like you've run the car with the timeing way advance'd and like how it did,, now your unhappy with how it performs in the stock configuation,, well keeping it that way or not is up to you,,but you can count on a very short engine life

 

you should feel how no retard does on an MPi with a 20g @20lbs , holly crap

[Bhughes]

I unpluged the vac adj and pluged it and reved the motor with a timing light on to confirm the mechanical adv is working and again with the vac adv to confirm it works.

 

 

And no it's not in my head. Car is undrivable at 10 btdc. Bucks hard and dies sometimes.

[Shelby]

ok the cam timeing is off , it's one or the other,, but undriveable is a strong term

[lionbull]

was this solved?

[Bhughes]

was this solved?

 

 

not yet. been busy on some other projects, starting to get back to workin on the starion. feeling is the timings off a tooth so thats where im lookin first.

[Bhughes]

ok so the cam timing looks to close to be off a tooth but maybe the head has been milled or something? the bolts holes for the valve cover line up inbetween the tip of a the tooth and the roller of the chain next to it. pictures...

 

http://img.photobucket.com/albums/v235/rx7anator/64bf8591.jpg

 

http://img.photobucket.com/albums/v235/rx7anator/084fd9dd.jpg

 

http://img.photobucket.com/albums/v235/rx7anator/621794c1.jpg

[Indiana]

The poles in the dist. do not touch and can't be touching. If the poles are touching then that part it rotates on is worn out. They rotate from the vac. advance pulling and pushing on them but the mechanical weights twist independently of the vac. adv. unit this way it allows the engine to see low rpm load adv. like it would in any car that used a vac. adv. its just that in this car it allows the boost to also retard the timing.

 

You might go back to the basics, check the spark plugs for being fouled or the WRONG type of spark plug. The compression numbers be in range. I see those are hydraulic rockers so make sure that's not a loud valev train and that all those rocker arms are hard if you push on the lifter end when the cam lobe has that particular arm you are pushing on at its base. If they mash down those lifters are dirty or bad or at least not getting oil to pump them up. You have jet valve intake rockers too so make sure those jet valves have clearance only after the motor has been ran and the lifters pumped up so if the lifters aren't working right it also screws up how the jet valves work.

 

It looks like an older head from looking at the valve train and if I had to take a guess I'd say that head has cracks in it and after it heats up its began to spray coolant into the cylinders and its not enough to smoke alot but it may be a little. If that's happening it will run good when its cold especially after its sat a day or two but when hot it will run like crap. If you can get someone to drive behind you and watch the exhaust that will help. You can also sniff the exhaust and see if it has a sweet odor from burning coolant. It doesn't have to be blowing out white smoke that's only after it has a great deal of coolant in the cylinders being blowing out and its just turned to steam is what you are seeing as the white smoke its not "burned" coolant.

 

and check this while you're at it

http://www.b2600turbo.com/images/ECICTS.jpg