turbo boost problems and rough start Topic is solved

connorclee42 · Post by **connorclee42** » 04 Jun 2019, 14:17

having a lot of trouble with maintaining steady boost on my 2000 volvo v70 xc awd. some time it work really good and other times it will get to around 10 psi then spit all the boost out completely and i have to let of the throttle and then get back on it to start building boost again. i have changed 90% of my vacuum line and have spend hours reading other posts and inspecting my vacuum line's. getting really annoyed. i have put a new ipd CBV kit in, ive changed the TCV (i have another on the way). The only two codes it ever throws it TCV and gross evap leak. could a bad evap leak be messing with my turbo? my understanding is this is after the turbo so i figured it wouldnt have an effect on it just gas millage. i have a new evap valve coming this week also and hoping that fixes the problem but i doubt it.. any help would be much appreciated

update: also this car usually has a rough first start. i either have to crank it a while then it will start and stumble a little and sometimes die, then the next time it starts right up and no problems. help please

BTW this care is bone stock.

Sommerfeldt · Post by **Sommerfeldt** » 04 Jun 2019, 14:36

Fix the evap leak. It’s an air leak, and these cars absolutely hate air leaks. Evap leaks will cause rough running, rich running, maf or map troubles, with the accompanying loss of power, codes, cat fouling if you’re not careful, etc, etc.

Take care of the evap leak, pressure test or smoke your IC and pressure hoses, replace the last 10% of vacuum hoses and you’re probably good to go.

- S

Post by **FlyingVolvo** » 04 Jun 2019, 18:24

connorclee42 wrote: ↑04 Jun 2019, 14:17 it will get to around 10 psi then spit all the boost out completely and i have to let of the throttle and then get back on it to start building boost again.

I've had this issue before. Double and triple check you have the correct TCV hoses going to the correct places. This car stock should not see more than about 7-8 PSI. Most people recommend the Pierburg TCV and not any aftermarket ones. I don't remember exactly what I did to fix mine, but I think it was a blown-off hose to the compressor (red).

connorclee42 wrote: ↑04 Jun 2019, 14:17 The only two codes it ever throws it TCV and gross evap leak. could a bad evap leak be messing with my turbo?

If it's throwing an actual code for TCV, I would check the wiring for damage too. The evap leak should be fixed, because though it may not directly tired to the turbo, it it part of the vacuum system and may cause irregularities that could then affect the TCV and turbo.

connorclee42 wrote: ↑04 Jun 2019, 14:17 also this car usually has a rough first start. i either have to crank it a while then it will start and stumble a little and sometimes die, then the next time it starts right up and no problems.

This sounds like to me the check valve in the fuel pump assembly. After the car has been sitting overnight next time, bring car to position II (but don't start) and listen for the fuel pump to prime. Repeat this several times by bringing the key out and then back to Pos II. After a few of those, try and start it. If it starts up well with no stumble, it's because the check valve is old and losing pressure while the car sits. Expensive and more correct option: replace the fuel pump assembly. Cheap and at-your-own-risk option: install an inline fuel line check valve somewhere.

If it still stumbles after the fuel pump priming, the issue is likely something else. Lot of variables, but leaky vacuum/evap system may cause troubles as well.

connorclee42 · Post by **connorclee42** » 05 Jun 2019, 06:32

thanks for the reply ecbsykes.I will double check by TCV hose and make sure they are going to the correct places, and i always buy the Pierburg TCV. almost thought about getting the HD IPD one but i didnt. I havent checked the wiring for the TVC so this is a good idea also, i will check it today as well. Hopefully i get my purge valve in today and can replace that as well, i read somewhere that they can fail in high heat. Also do you happen to know where my evap canister is on this car? i havent been able to find it yet but i havent put it on the car lift yet to look under it.

Is for the fuel system i have tried turing my key to possition two a couple time and that didnt seem to work. i also tested the fuel pressure last month and if i remember correctly it was around 54 or 57 PSI which i read was good. Im hoping the evap leak is the cause of the bad start because other than that it seems to idle really good. But if it does set idle for more than five minutes then i give it some gas it smokes out the exhaust.

connorclee42 · Post by **connorclee42** » 05 Jun 2019, 06:39

thanks for the reply also Sommerfeldt. i have been trying to make a homemade smoke machine but havent had much luck yet. i bought a 30$ fog machine hoping i could save some money and it didnt produce the smoke i need. Vacuum leaks are so frustrating and hard to find.

What do you mean by "cat fouling"? also what do you mean by smoking your "IC" im not up to date with all the lingo

connorclee42 · Post by **connorclee42** » 05 Jun 2019, 06:44

Also i forgot to mention i have vacuum/boost gauge hooked up to this and when i start the car it pulls right around 15hg and around 20hg when warm and doesnt really seem to fluctuate. is this a normal vacuum?

Sommerfeldt · Post by **Sommerfeldt** » 05 Jun 2019, 07:05

Sorry, didn’t mean to be all lingo and alphabet soup - we are supposed to use proper language around here (I see you there, abscate

).
Running rich for longer periods, which is one of the things an air leak can lead to, is fouling the catalytic converter. It’s expensive and troublesome. As for IC, I mean you should include the intercooler when you pressure test or smoke test your hoses and airways, so to speak. A leak in that can cause weird symptoms as well.

- S

connorclee42 · Post by **connorclee42** » 05 Jun 2019, 07:11

haha no problem. i have about zero knowledge of what the catalytic converter really does. if it does go bad would it throw some kind of code for that?

also, what is the best place to hook the smoke tester up too? would the hose from the intake manifold to the booster pump be a good place?

also having a hard time finding a good vacuum diagram for my car. all the ones i see it looks like they have a different set up/TVC

Sommerfeldt · Post by **Sommerfeldt** » 05 Jun 2019, 11:36

Yes, but it does take a lot of black smoke out the tailpipe before you fry a catalytic converter. Don't worry about that right now. You're lucky you have codes to work with - if you haven't done so already, clear your codes and see what comes back. That's how you filter out the "real" codes from the occasional hiccup.

Your vacuum numbers seem to be in the right area. My first priority would be to chase those two - you might not even need new parts, only some new hoses for the evap and a check of the TCV routing and connector. The Pierburg units rarely go bad, as far as I can tell - I'm running one of them on my 850 right now, and it's very responsive, as far as I can tell, even more so than the iPD HD unit.

Chase down what's wrong with the evap, and replace the rest of your vacuum hoses with new ones, just for the peace of mind, if nothing else. Chase the TCV issue. When you've addressed what you have codes for, see if there's still a problem.

- S

connorclee42 · Post by **connorclee42** » 05 Jun 2019, 11:51

So on lunch today i went out and looked at my TCV routing and i believe i had two of the lines in the wrong place. the one from the compressor and the one for the fresh air. i switched them and then went for a drive to get something to eat but i had my wife with me so i didnt give it much throttle to see how it would act. i will do so more after i get off of work. im hoping that fixes the problem. but also a double edge sword here because with the lines how they were i would some times geet a constant 10psi of boost which feels real nice on the car. on lunch it was staying around 5-6 which feels real sluggish now.

i always clear the codes and TCV always came back(probably because i had it hooked up wrong) and the gross leak has only showed up twice. i might go and put it on the lift today and try to trace down all the evap lines. Any idea where to find theses?

Also on a new note, does anyone recommend putting any type of tune on this car? it just hit 200,000 about two weeks ago