WillM

I have what appears to be a fueling problem that I'm stumped on. 75%-WOT car bog's horribly and ceases acceleration around 3k rpms. This started about a week ago and progressed rapidly to the point it is now very consistent. The car is a 94' civic with a B18C transplanted in. It was formerly a turbo motor, but has since been returned to stock with the exception of an MSD pro billet ignition. I have a Greddy turbo timer that shows A/F go very lean when this is occurring. Plugs show signs of lean running as well. When not trying to accelerate quickly, the car runs perfectly. I commute 100 miles a day on interstate and car has no trouble maintaining speed, quick to start and smooth idle. Btw, no CEL (although for once I wish)

So far I've changed the fuel filter and then the pump. After the pump, it was slightly better, but sill very much still a problem. engine accelerate strong to around 4500 - 5k now and just hangs as before. Never any jerky and doesn't sound like it's misfiring.

Ideas please? I have searched the forums and been through the shop manual, but I'm out of ideas.

mouab18c1

iTrader: (5)

Are you back on the stock ecu?

WillM

Yes, Unmolested p72. Also, stock injectors, FPR, etc. I did forget to mention it has a skunk intake manifold for what that's worth. It's also worth mentioning that the car was driven for months in its current config before this problem arose.

Thanks again

WillM

Anyone have and ideas?

fcm

Pull the MSD and try stock "ign", we replace 2-5 MSD systems a year for pretty much the same symptoms as yours mostly on street rods that have stock points system replaced with MSD pointless systems.

Although I have MSD in my 94 Integra and love it, my boss hates MSD and would never recommend it to anyone, he thinks it's over-engineered and that is why it has problems, so far on the ones we have replaced he has been right, the problem was the MSD system.

This may not be your problem as I do not see how a problem with the MSD would result in a lean burn situation, however if it's an easy swap, do it for no other reason then to eliminate it as the problem 94

WillM

Sorry for the delay, but I'm still trying to figure this out. Finally ordered the ignitor and coil to get the OEM dizzy working again and swapped it back to stock ignition. Started right up but then I took it out and same issue exists. Car runs normal until you try to take it above 3k from 75% to WOT. Then it's like it's suddenly dragging and anchor and ceases acceleration although the engine remains smooth and sounds like it's trying. If I feather back the throttle I can nurse it up in the RPMs, but as soon as I put my foot back down, it chokes back down. No CEL but I jumped it anyway and no codes were displayed. This is driving me crazy and getting expensive. Anyone with any ideas would be greatly appreciated!

scmil95eg

Is there a resistor box still in the car?
Is fuel pressure accurate/steady while it's stumbling?
Are the washers & damper in the correct orientation on the fuel rail feed?

fourthgenhatchB17

Do the basics first, like check fuel pressure. You said you changed the pump and filter, but why? Were you hoping to get lucky or did you confirm low fuel pressure?

WillM

scmil95eg, you are my hero.
I had tested the fuel pressure, but it read way to high. I figured my pos Harbor Freight gauge was bad as high fuel pressure certainly wouldn't cause what appeared to be fuel starvation. Well it never occurred to me to second guess the connection from the fuel line to the rail. Over 6 mos ago I had the fuel line off, dropped and lost the washer between the damper and the line. Figuring it was the same as the other 3 washers on the fuel line, I tossed a new 12mm copper washer in there and ran it. After reading your suggestion, I checked another motor I have lying around and realized the washer I lost is different to allow fuel to pass. I pulled mine off and sure enough, some very fine debris has collected and plugged what little room the fuel had to go around the sealing washer. I gues that's why it ran for a while. Hard to believe after months of trying to diagnose, a $2 washer is the fix.
Much thanks to all for your help!