blown_volvo850r Posted August 7, 2009 Report Share Posted August 7, 2009 About three months ago, I had the replace the motor in the R. The headgasket was blown and the head was warped .015". The coolant lines in the block were completely sludged up, so we located a new engine and had it put it. There was some shoddy workmanship on how everything was put back in, but I fixed most everything that wasn't done properly. About a month ago, I started having some issues. For the first minute or two of ignition, the engine would bog down and after holding it at 2K rpms or so for a few minutes, it would clear up and run fine. However, it's gotten a lot worse to the point where it barely runs for the few minutes. At first, I thought it was possibly an issue with getting the engine warmed up, but it wasn't. Once the engine was warm, simply switching the ignition off, then right back on would create the same problem. One of the regulars at my work mentioned a "warm-up" period in which the computer drops the fuel pressure in order to lean the AFR a bit and get the engine warmed up more quickly. However, sometimes it would do it and sometimes it wouldn't. I considered that my ECU is mapped for 350cc injectors and the stock fuel rail only had 305cc oranges. I swapped out the fuel rail and put the adjustable FPR back on. Still didn't work properly. I also noticed that one of the hard fuel lines on top of the block next to the timing belt was left open and a hose that ran to a nipple on the intake manifold was sealed off with a bolt. Spencer (can't remember his sn on here) told me the hard line is simply an evaporator line that allows the gas tank to relieve pressure and normally gets run to the intake manifold. On my first engine, that line was run to the FPR, so I did that. Still nothing changed. I did notice throughout the previous month that the car ran poorly when it was wet, and when we had a severe rainstorm on Tuesday, hitting really deep puddles caused my engine to completely bog down and almost stall out. I'm considering the possibility that water had gotten into the open line and ran down into the fuel tank. I also noticed when I cleaned my air filter that during a rough idle, I was able to smooth the idle out by slightly putting my hand over the intake pipe (once the filter was off). Clamping it completely over the pipe obviously stalled the engine, but when it was left open, it had a rough idle. Putting my hand an inch or so away from the pipe smoothed the idle, so my guess is that the engine is not getting enough fuel. Had the problem been too much fuel, I doubt the car would've started immediately after stalling out. Tonight when I was working on it, the engine would start very strong, but within a few seconds, the vacuum reading would drop to 1-2 inches as it bogged down, then would stall. If I intermittently popped the throttle, it would rev up, and at close to WOT, it would rev like normal. However, holding the throttle down (around 2-3K rpms) would do absolutely nothing, as if the throttle was not being opened. It's not a throttle cable or throttle body problem as I've already checked both and they are working normally. One time tonight, I was able to get it through the first few minutes without stalling, but it still had a rough idle and was only holding 10 inches of vacuum, give or take. I looked everywhere for a vacuum leak and was unable to find one. Even if there is a vacuum leak, it still doesn't explain the fact that the car barely runs once started until it clears out. It wasn't doing this when I got the car back from the shop, and since it's started, it's gotten progressively worse. However, it's been it's worst after I went through the puddles on Tuesday afternoon, and I'm wondering if it's water in the tank and the deep puddles got a lot of water in there. I'm planning on changing the fuel filter in the morning to see if that helps any. I did consider the possibility of a bad MAF sensor, but when I had to replace it a couple of years ago, the problem was persistent. It didn't only cause AFR issues at startup, so I really doubt it's a MAF-related issue. The engine has brand new ignition components (plugs, wires, rotor, coil pack) and all fluids are a go. Brand new front O2 sensor as well. Something else I noticed was that the intake manifold has three nipples on it where my first manifold only had two. Two of mine now are capped off, and I'm wondering if I should run vacuum lines from the manifold to the vacuum tree. It seems to me that if the car is getting too little fuel at idle, pulling air from the manifold to the tree might help. Any advice on this would be greatly appreciated. The most logical theory is that the open evaporator line has been letting water get into the tank, and the excessive rain from Tuesday got enough in there to keep it from even running. At first I thought it might be too much fuel, but the engine has not flooded at any point. During the rough (almost stalling) idle, I adjusted the FPR from 35psi to 65psi and back down, and no rise or fall in fuel pressure changed the idle. I also put some water evaporator in the tank, but in the couple of hours I was continually trying to get the engine to run, I saw no visible results from the evaporator. Link to comment Share on other sites More sharing options...
FCP Euro Posted August 7, 2009 Report Share Posted August 7, 2009 I am thinking it is either a bad vacuum leak, or your fuel pump might be going. Link to comment Share on other sites More sharing options...
flyfishing3 Posted August 7, 2009 Report Share Posted August 7, 2009 i wouldn't rule out MAF. also does the 97s have a IAC? if this was my 98, i'd be looking all over the hoses to the IAC and the IAC Link to comment Share on other sites More sharing options...
7 VII 7 Posted August 7, 2009 Report Share Posted August 7, 2009 i wouldn't rule out MAF. also does the 97s have a IAC? if this was my 98, i'd be looking all over the hoses to the IAC and the IAC Yes Link to comment Share on other sites More sharing options...
blown_volvo850r Posted August 7, 2009 Author Report Share Posted August 7, 2009 Forgot to mention that I already pulled the IAC out and cleaned it as well as triple checked the hoses running to and from it. No problem there. I did some more reading last night after I posted and from what I've read, fuel filters won't pass water, so a significant amount of water in the tank will clog the filter. I bought a new filter earlier today and I'll be putting it in shortly. Fuel pump could also be going bad as water can damage it as well, but I'm gonna try the filter first and see if that helps. I looked everywhere and could not locate a vacuum leak. That being said, if the engine isn't getting enough fuel to keep a steady idle, it won't generate full vacuum, even if there's no leak. So it could be a vacuum leak, or possibly just low vacuum due to lack of fuel. I'll post up later once I have the new filter in and drain some of the tank. Link to comment Share on other sites More sharing options...
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