loftygoals Posted July 27, 2008 Posted July 27, 2008 So last weekend at Autobahn my 944 went limp above 5000 RPMs 3/4ths way through the 3 hour enduro. When we came off of the track, the fuel pump was buzzing like crazy. We assumed we had a clogged fuel filter and we threw in a spare that Eric had. When we pulled the old filter, a ton of nasty stuff came out. Upon installation the fuel pump was now noise free again. When I raced on Sunday, the car still didn't have any power above 5000 RPMs. In 3rd gear, I couldn't even get the car to make it to redline. Yesterday Rob replaced the fuel pump, associated lines, another new fuel filter, and a new in tank filter. A quick test drive by both me and Rob confirmed the problem was still there. (It also revealed a brake problem which turned out to be a rotor that was crack all the way through the outer surface.) We didn't have room to test anything but 1st and second gear, but in Rob's words “the car was gutless above 5000 rpms.” I agreed. So, what could the culprit be? We have a extra damper and regulator we could through on. The weird thing is that low power delivery feels strong. It almost makes me wonder if the belt slipped a tooth. I will try to confirm that the timing is correct today. Any other ideas? Thanks, -bj Quote
JSilverman Posted July 27, 2008 Posted July 27, 2008 Do you still have a cat on the car? My car had the exact same symptoms when a piece of the honeycomb broke off and clogged the exhaust. Quote
loftygoals Posted July 28, 2008 Author Posted July 28, 2008 Do you still have a cat on the car? My car had the exact same symptoms when a piece of the honeycomb broke off and clogged the exhaust. Nope. Pulled a lot of honeycomb out of the muffler when we did the exhuast, though. -bj Quote
Sterling Doc Posted July 28, 2008 Posted July 28, 2008 Coolant temp sensor? AFM wiper tracks ( they usually cause it to cut out entirely when they go, however). Seems like the FPR would be the most likely culprit. We could bring spares to R.A. Quote
MadConan Posted July 28, 2008 Posted July 28, 2008 Sounds air flow related. So either enough air isn't getting through the AFM (or the AFM THINKS there isn't enough air) so it's cutting fuel. Maybe do the thing that Eric mentioned to me about the AFM? I tried to get the cover off of mine but couldn't do it. Quote
rfreundt Posted July 28, 2008 Posted July 28, 2008 It could be the AFM I have one off an 85 I could bring it to RA if you want. If there anything else that could be the culprit please advise us as I have all the parts from the running 85 that would work on BJ's car. Quote
DavidH Posted July 28, 2008 Posted July 28, 2008 Fuel and/or electrical. I had something similar where it felt like the rev limiter kicked in under load on certain turns. I replaced and you might want to check the FPR, dampener, filter, fuel relay and injectors. Tested the AFM. Then went with electrical checking DME, plugs, wires, coil, cap and rotor. Unfortunately I never found the culprit, but when we put the new motor in I have not had any issues. Oh, and I tested the head temp sensor. It was like looking for a needle in a haystack, but with this list you may have better luck with it than I did. Good luck. Quote
944-Spec#94 Posted July 28, 2008 Posted July 28, 2008 Worst case is a valve spring issue. There are two valve springs for each valve and if one fails the valve will not operate properly at high RPM, but can work at low RPM. Result is no power up high. Check all the electricals first because those are easier and cheaper to solve. Quote
rfreundt Posted July 28, 2008 Posted July 28, 2008 That was a good call on the valve spring issue, I never even thought of that. Lets just hope its not the latter one BJ. Quote
loftygoals Posted July 29, 2008 Author Posted July 29, 2008 Last night I fixed the car. You never believe what it was--rubber boogers. My intake was completely clogged with them. Removed them and I have a happy car again. The bad news is that I won't have the truck fixed in time to make it to RA. I'm still going to be racing, though. Theres a SCCA ITS race this weekend here in St. Louis. There are 2 other 944's signed up, so at least I'll feel at home. I'm bummed that I won't be racing with you guys, though. -bj Quote
944-Spec#94 Posted July 29, 2008 Posted July 29, 2008 Last night I fixed the car. You never believe what it was--rubber boogers. My intake was completely clogged with them. Removed them and I have a happy car again.-bj There is small baffle you can put in between the chassis and the fender to keep rubber from getting sucked in the intake. Good idea to either install it or fab something. It also helps prevent water from getting in. Early cars and the 924S came with that black plastic panel. The 924S one only fits in the 924S due to the narrow fender. The late 944 uses a complete fender liner that gets ditched during the stipping process. I am not certain if the early one will fit. Even so you should be able to make something that will work. Quote
loftygoals Posted July 29, 2008 Author Posted July 29, 2008 There is small baffle you can put in between the chassis and the fender to keep rubber from getting sucked in the intake. Good idea to either install it or fab something. It also helps prevent water from getting in. I had covered the opening with mesh. That kept the ruber out of the airbox, but the rubber still accumulated on the mesh. It's always the little things. -bj Quote
Sterling Doc Posted July 30, 2008 Posted July 30, 2008 This is what came out of Ray's Filter at Miller Quote
Sterling Doc Posted July 30, 2008 Posted July 30, 2008 BJ whats up with the truck? Be like Norm, drive the car in! Quote
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