Highly Modded 4G63 Not Dependable??

[1G90AWDTsi]

I have a 1990 Talon AWD Tsi with a new block (shaved, bored, honed), new JE pistons 85.5mm IDT, new HKS cams 264i/272e, new crank (balanced and polished), new ACL Race rod/main bearings, new Cometic HG, new APR Head studs, new Cylinder Head (3-angle valve job and internals), new 16g Garrett Turbo, new 750cc Fuel Injectors, new DSMLink (somewhat tuned), ECU chip was sent out for tech work, ported O2 housing, eliminated Balance Shaft with block-off bearing, ALL new belts/seals/gaskets on entire engine and accessories, new Powder Coated Exhaust Manifold (sorry). ECU set for factory boost, NO booster.

Drove car for 1100 miles and spun all four bearings and scored crank due to improper installation of block off bearing for BS. Then, replaced all bearings and turned crank then micropolished crank and correctly installed block off bearing. Also, added 750cc fuel injectors and tuned with DSMlink (just the basics).

PROBLEM: Car runs good for about 20 minutes and then starts hesitating and sputtering all throughout acceleration in all rpm ranges and all gears.

PROBLEM 2: For first 20 minutes of driving, no leaks at all can be traced anywhere. After 20 minutes however, car starts leaking oil (about 1/2 cup onto pavement (oil filter is covered on top and 3 bolts on oil pan have oil on them)). New gasket and new oil pan. What to do??

Engine was built 1st time by pro shop in Texas. Then engine was repaired (bottom end) in NH at turbo shop.
Check out the assembly of the motor at http://new.photos.yahoo.com/[email protected]/albums and click on the
4g63 pic.

 

[staticbrainwash]

Check all your timing marks, check ign. timing. Then, move to a power balance test when it's hesitating. There might be a slight miss.

It doesn't sound like a motor issue now.

I have a freshly built 4g63 from buschur and 4500 miles so far it's had ZERO issues. I've got 8.5compression, no BS, no AC, manual cams. Not quite like yours, but still buit a bit.

Check your basics with it hesitating. Spark, fuel. Then move to a compression test. Then a leakdown. Post results.

 

[1G90AWDTsi]

I haven't had it fine-tuned yet, do you think everything you suggested as far as the readings can be done at the dyno?

 

[staticbrainwash]

I guess so. But you'd save a lot of money doing it yourself.

 

[perley03]

I have a 1990 Talon AWD Tsi with a new block (shaved, bored, honed), new JE pistons 85.5mm IDT, new HKS cams 264i/272e, new crank (balanced and polished), new ACL Race rod/main bearings, new Comedic HG, new APR studs, new Cylinder Head (3-angle valve job and internals), new 16g Garrett Turbo, new 750cc Fuel Injectors, new DSMLink (somewhat tuned), Upgraded ECU Chip, ported O2 housing, eliminated Balance Shaft with block-off bearing, ALL new belts/seals/gaskets on entire engine and accessories, new Tubular Intake Header. ECU set for factory boost, NO booster.

What you are saying doesn't make any sense. First off, Garrett does not make a 16G turbo. Mitsubishi Heavy Industries (MHI) makes them. Second, you can either have DSMLink or an upgraded ECU chip, can't have both. And what is a Tubular Intake header? Tubular exhaust manifold or a sheet metal intake manifold? And you don't set your ECU for boost, it uses the factory boost control solenoid, which is regulated at 12psi, unless you bypass this with an aftermarket boost controller.
If I were you I would revise your list of mods so other knowledgeable people can help you out.
Not ragging on you or anything, just stating that what you posted does not make sense, will confuse a lot of people who read it, and they probably won't reply.

 

[Talesin]

1) The 20-minute thing may be the car switching out of warm-up mode. Did you tune the car warmed up, or still cold? Is your FPR solenoid still hooked up (between the manifold line source and the FPR) or are you running a straight, un-cut line from the manifold to the FPR?

2) Follow the leak upward. Find the source, clean all the oil off, fix the leak, and drive it again to find any additional leaks. It doesn't come from nowhere. If you still have your power steering, make sure it's an oil leak, and not a P/S pump leak, since it's directly above the oil filter. Usually you can tell if you have to keep topping up your PS fluid. May also just be the oil filter not being snugged down, or some kind of cruft on the oil filter housing breaking the seal. If you can turn it with your hand, it's not on properly. Don't have to worry about crushing any kind of oil/water oil cooler like on the 91+, since we have the external oil/air cooler.


As noted above. DSMLink is an EPROM replacement. You don't have an upgraded EPROM, you just have DSMLink, or possibly just an upgraded chip and a logger cable.
Tubular exhaust manifold. Turbo cars don't use headers at all, much less for the intake, and no one makes a tubular intake manifold.
Cometic headgasket. Not comedic.
ARP studs... headstuds, I assume, and not main bolts.
The ECU uses the BCS to bleed a little of the boost reference from your wastegate vac line (when hooked up in stock configuration) so the WG stays closed longer, allowing the turbo to boost a bit more, raising the pressure from 10psi to 12psi when no knock is detected. Drops back to 10 with enough knock (closes the bleeder). You can't really change that part, aside from setting a direct line from the boost source to the WG (making you run at 10psi all the time) or carefully removing the BCS restrictor (as seen on vfaq.com), allowing it to go up to around 14psi. There's no ECU setting that will change that. Understood that you don't have a boost controller in the loop.

Get your global deadtime and global fuel compensation set up correctly for the 750s (there are charts up on the DSMLink forums to give you a 'start point'), then leave the rest zeroed. Fix the leaks, and then we can start troubleshooting the other issues. :b Really jumped in with both feet, din'cha?

 

[1G90AWDTsi]

Sorry guys, this is my first turbo car, still learing about them. THANKS for responding too and I will definitely check into all the advice and see if it helps my car, I've been trying to get it to the dyno "TDC Tuning" in NH, but the guy has a waiting list about 3 weeks long (only AWD Dyno within 100 miles)!!

When I first got the car and had it built in Texas, the mechanic (my cousin) installed a manual turbo booster and told me he set it to 14psi. After shipping the talon to NH, it ran great for the first 1100 miles with no problem except for coolant pouring out of the overflow tank onto the ground, apparently my cousin didn't torque the head down to spec and I had a leak. When I brought the car to my current turbo mechanic "balistic motorsports" in New Hampshire, he insisted I get a cometic head gasket and install it. I did. The coolant problem was fixed.

Then it had a clicking noise and real low oil pressure which turned out to be the rod bearings being spun and a scored crank. My cousin didn't install the block off bearing correctly. My current turbo mechanic then fixed that problem and turned the crank and installed ACL race main/rod bearings and correctly installed the block off bearing $2200. That was done only 115 miles ago. 2 weeks ago he had the ECU sent out for what I thought was upgrading but I guess it was something else. I also got the DSMLink which he used to tune (very basically) after he installed 750cc injectors $700.

I asked him if I needed a bigger fuel pump and a regulator (could this be part of the problem?) and he said I didn't and also he said the sputtering issue was not having the car "fine-tuned" and it would go away after doing so. I just took the car out for a quick 10 minute drive and romped on it pretty hard. It drove great no probs and no leaks. I don't understand it.

I bought this car in Sept. of 2005 and only have barely put 1200 miles on it (It sat in my driveway for loooong periods of time while I saved to get it fixed for the damages above, now it's running again but I'm very skeptical about how long it will last before other crap comes up (I wish I had the mechanical skill to work on it myself, I'd have saved a lot of cash).

Thanks for all the response, I really appreciate it!

 

[Talesin]

Sounds like your mechanic somewhat knows his stuff... but he's full of crap if you're still on the stock fuel pump and FPR. Maybe if you keep the boost low... but then what's the point in having the larger injectors if you're just going to rock stock?

My recommendation would be a Walbro 255 High Pressure in-tank pump replacement, rewiring the fuel pump (instructions are on VFAQ.com), and getting an Aeromotive adjustable fuel pressure regulator (AFPR) with an install kit from somewhere like Import Evolution. Where I got mine. At that point you should be good to bump the boost down the road.

Getting the sputter fixed is again most likely just setting up the global deadtimes and global fuel adjustment in DSMLink. There are tables on the DSMLink forums of 'base' settings, and instructions on how to fine-tune them to run absolutely perfect on your car (watching the short versus long term fuel trims, getting them to match up with global deadtime adjustment, then zeroing them out with global fuel). It takes about an hour or two, but you can do it yourself, and it will fix a lot of running problems. Spend the hour or so, do it yourself... it's really not hard. And do it ASAP!

Not to be offensive, but sounds like your cousin didn't know what he was doing, and ripped you a new one in the process. Hoping he's at least paying for part (if not all) of the new/rebuilt engine?
You likely had the capacitors replaced... the OEM ones are electrolytic caps, and WILL leak over the years.. main cause of failure and weird behaviour in a lot of our cars.


Er... if the engine is leaking, and you just had it done at a shop... take it to the shop. Warranty work is a beautiful thing, and a right-there, hands-on mechanic will be able to find and diagnose a weird leak like that MUCH faster than an internet forum will. :b Even if we had pictures to work from.

 

[1G90AWDTsi]

Excellent Info, thanks! I will definitely get that walbro fuel pump and aeromotive regulator like you said.

I have a current laptop (toshiba) and my mechanic left the PC connecting cord in my car still hooked up so all I have to do is connect that to my laptop, install the software and start tuning? Should I install the FP and AFPR first and then tune? And last question, should the car be running when tuning?

Yeah, my cousin is a good mechanic but I found out after I got the car up here in NH that he never built a turbo engine before and was only getting advice on parts to put in it and he knew nothing of fuel management and tuning, I kinda felt like he experimented on my dollars. He did send me "some" money to help out with the repairs but not really to my satisfaction.

Thanks!

 

[1G90AWDTsi]

I went out again for another short ride and when I got back, I popped the hood and tried to see if I could see the injectors leaking just out of curiosity. Anyway, I found that belt that rides on the outside of the timing belt lower cover, is grinding and cutting into the timing cover! It's doing it at the rear of the motor (driverside) and also at the front of the motor (driverside). ???

 

[cbassgsx]

sounds like a timing tensioner issue

 

[Talesin]

Yes, yes, and yes.

Focus on getting it running right before you start to really work on power. And definitely get the Walbro/AFPR installed before you start tuning, aside from the global deadtime/fuel compensation... you're going to have to go back and make sure your deadtimes and global fuel trims are accurate once the pump and AFPR are in, and you have a reliable fuel pressure to start tuning from. Also, rewire the fuel pump (as seen on VFAQ) so you won't have to screw with it again. Doesn't take long, and it helps out a LOT down the line.

You have two belts on the outside of the timing cover. The one toward the firewall is for your A/C compressor. The one to the front should be your power steering and alternator. If it's rubbing on the lower timing belt cover, either the cover was not installed properly, or something behind the cover is shoving it outward (ie: not installed properly).


On tuning (after the leaks/belts/fuel pump & regulator are dealt with):
At first, you're going to be going with a rough tune. Log knock, airflow, throttle, RPM, speed, injector pulse width, injector duty cycle. You want to start out fairly rich, and SLOWLY lean things out bit by bit until you start to pick up knock, then richen them up enough that you don't any more. Third gear pulls are good for this. You can also reduce timing a bit instead of increasing fuel, it's a balancing act. More timing means more power, as does leaner running. Knock means your engine is about to kill itself though, so you want to tune for ZERO if possible. If you're getting wonky knock readings (read up on 'ghost knock') you'll want to replace your knock sensor, if it's aging or degrading at all.

Down the line, you'll want to get a Wideband O2 (among other things). This gives you a precise read on your air/fuel mixture (unlike those worthless, shitty lightshow air/fuel gauges that tap into the stock narrowband O2 sensor), so you can know exactly what you're running and predict more accurately when knock will occur, and how much knock is 'safe' as a margin for error (knock only caused by intercooler heatsoak, fuel aberration, residual heat, etc). You'll also be able to adjust the timing curve MUCH more accurately and easily, making the balancing act above much easier to pull off, and pull out every last horse.

 

[1G90AWDTsi]

Thanks for the information, my local mechanic sells the walbro 255 FP for about 100 bucks and will send out for the AFPR asap. He said again, I don't need this stuff but I've been reading a lot of forums that say I definitely do. That wideband O2, where can I pick up the right one for my 90 Tsi? If I'm only going to run factory boost (for now) will a stock intercooler kit be good enough for daily driving after the car is tuned right?

Thanks again!

 

[staticbrainwash]

You should be fine on stock boost yes. Wideband is universal really, you just need to weld a bung into the exhaust.

Aem makes a good wideband, as does innovative. Both are universal kits that will tell you all you need to know!

 

[1G90AWDTsi]

Good to know, thanks. Got a quick question...besides installing a block-off bearing after eliminating the balance shaft, what else has to be done in order to keep the oil where it belongs or is that all? Just thinking a wild thought that maybe that has something to do with my oil leak.

 

[schoffs4]

im in derry nh and have my own shop ill take a look at it if you want

 

[1G90AWDTsi]

Excellent, where's your shop? I'm over off Old Derry Rd (exit 5 on 93). Thanks!

 

[1G90AWDTsi]

I had my mechanic check out the oil leak, he said it was coming from behind the timing belt cover which is not in good condition. He said if I can find a complete timing belt cover in good condition, he will install the new one after he fixes the leak (covered by warranty)...anyone know where I can find a complete timing belt cover? I saw one for $150 on dsmparts.com, kinda pricy though.

 

[staticbrainwash]

Machv sells the top and bottom sections of the cover in their maintenience section.

 

[grnchevyz]

The leak you are experiencing is coming from your balance shaft tensioner pulley bolt. Most likely your cousin did NOT put the bolt back in or replace it with a shorter one thus resulting in oil escaping from there. It is positioned behind the cover of course

Here is a pic of where to locate it. I believe the bolt you will need is an M12x15 or M12x20

Enjoy!

 

[schoffs4]

I live in derry my shop is in methuen off 213 exit 3 called pro auto repair be glad to help

 

[1G90AWDTsi]

I'm going to bring my car by next week to your shop and have a look. Thanks!

 

[1G90AWDTsi]

grnchevyz, I KNOW my cousin didn't do anything to fix the BS issue, and my turbo mech. only said he replaced the block off bearing and never said anything about that bolt issue. Thanks very much for the info on that, I was thinking pretty strongly that the BS issue wasn't quite finished yet. Thanks!!

 

[1G90AWDTsi]

Anyone know when would it be "necessary" to install a front mount intercooler? I only have the stock intercooler and really don't want to buy a FMIC unless I absolutely have to. I will only be running stock boost even though I have all the mods. Can I get away with a piping upgrade kit for my stock I/C?

 

[bling5tatus]

water/alcohol injection is a way to dodge having to buy a bigger intercooler.