WIERD! 6 & 7 bolt cam gear combo question

[black97spyder]

Hey guys, sorry about the long post in advance. I just bought a '90 tsi awd today (my first 1g and first 5 speed DSM) for dirt cheap.... It runs and drives a little rough because the previous owner had installed a wally 255 in the tank and didn't have an AFPR to keep it from overwhelming the stock FPR... (he said it needed a tune because it wasn't getting enough gas, haha) so im going to install my wally 190 in it 2moro and hopefully that fixes everything (im sure it will because I smell a ton of gas when its just idling and at low rpms then I get into boost and it actually runs decent)

BUT, IF that doesn't fix the problem then this leads my other potential problem and the wierdest thing ive seen with a dsm so far.... it has one 6 bolt cam gear on the exhaust cam and a 7 bolt cam gear on the intake side but thats not the end of it! The previous owner also changed the H.G. and put a cometic MLS H.G. in with ARP head studs, and when he went to install the 6 bolt head studs, they were too big so it had a 7 bolt head on a 6 bolt block?? So he used 7 bolt ARP's on a 6 bolt block? ( he also said it was having overheating problems and then found he had a blown H.G. and on top of that i dont think he surfaced the block or head (but will ask) and upon re-timing the motor is when he found out it had the two different cam gears.


Im just wondering if you guys think the same as me and it will only be a simple fuel pump swap (keeping fingers crossed) or do you think the combo of all those 1g & 2g parts (mainly cam gears) is causing it to run rough??

Thanks!
-Matt

 

[motomattx]

The cam gears shouldnt matter really, they are both the same size but the 2ga has a cam sensor trigger on the back of the intake.

 

[synthetek]

The cam gears don't mater. Not having the head & block prepared properly for a mls head gasket and not having the correct head studs would be the bigger problem.

 

[2slow4now]

Sounds awfully fishy. Are you sure it doesn't just have a 95-96 motor swapped in? I would say that is the only way the cam gears would look different. You use the same aftermarket cam gears for 1g, 2g and evos. Probably several other cars too.

On 7 bolt arps installed in a 6 bolt block there's about 1mm size difference between the two. So the threads wouldn't fully be engaged. They would probably pull out or strip out. Thats why I would think its a 7 bolt in your car.

Cheap car oh well. Swap the pump and tinker away. Should be fun.

Get some pics posted up.

 

[black97spyder]

I didn't think they were different but I wasn't 100% sure on it.

As far as running rough do you guys agree its the fuel pump overrunning the stock FPR causing it to run rough due to it being a stock wore out '90 fuel pressure regulator??

(at a low rpm with injectors barely flowing its rough, then under boost with a 16g at 10psi the injectors are flowing enough so that the pump doesnt/isnt overruning the stock regulator as bad) and it runs kind of decent under boost... but judging it is hard because im used to 24+psi on a 20g auto car tuned very aggressive so im not used to the huge boost difference, smaller turbo, boost lag and stock cams of this car


2slow4now - I know it has a tranny mount on the passenger side (didn't think 1g's had a tranny/engine mount on that side), 1g t/b, 1g intake, 1g thermostat housing (think its a '90 but not sure of there is any difference on the 1g's) '90 OFH with OLD oem oil cooler, and a blacktop cas that is plugged into the firewall like it should be but other than that.... no im not sure its not a 95-96 motor and it has great oil pressure (and supposedly 143k miles on the lower end) so I dont want to tear the oil pan off to look at the rod sizes compared to my 7 bolt rods

 

[2slow4now]

Yeah if the fpr is getting over run at idle then it sure could. The injectors have no idea there is more fuel available so they just open like the fpr is doing it's job. More fuel is available than normal since the fpr can't dump the excess back to the tank so it dumps out the injectors. Makes me think back when I was a kid throwing a big carb on a beater v8. Get on it and it stutters until she lights off then wwwhhhooo!

 

[black97spyder]

Yep that was exactly my thoughts as well! Your making me feel alot better about picking it up for $1600 running and very likely needing a smaller fuel pump as the fix .

wish I could post pics on the site but it wont let me, but i think it is the cleanest interior on a that 1g ive ever seen and everything on the dash works!! Except for the tach until 2moro (P.O. never plugged the noise filter back in or lost it after doing the "H.G. job")

 

[black97spyder]

Well when I went to change the "walboro 255" out of the car that I was told was in it, I found the stock fuel pump still in the tank.... so since i was there I went ahead and swapped my wally 190 in and then the car would try to start but never actually start......

SO, would a old stock FPR cause the car to idle rough and then once under boost it runs decent?? (not great but driveable) and def has a miss until you get under boost then the miss gets better but doesnt go completely away.

would one tooth off on the timing job he did cause it to run rough?? Or maybe due to mixing 6 bolt and 7 bolt cam gears ('90 exhaust cam gear and 97-99 intake cam gear??

it also has tons of boost leaks as well, which from my experience hasnt ever caused my other dsms to run rough