October 27, 200718 yr Some of you are familiar with my Weber dilemma and the associated problem with backfiring through the carb when under load and sluggish acceleration, etc... on the '84 wagon. The wagon had a heart transplant. Shawn, Jerry and I installed a perfectly strong running, Weberized, motor and exhaust system from another wagon this past week. Again, I want to stress that the motor we installed ran flawlessly (had a blast driving the rust bucket it came from)... The wagon starts and idles w/o issue (Just like the original motor with the NEW Weber we installed) but we are experiencing nearly the same problems of backfiring, rough and sluggish acceleration, etc... I am honestly at my last nerve and don't know what to do. -timing is spot on -there are no vac leaks -master has been replaced -hoses are fine -coil, plugs, disty are good We swapped the fuel pump last night and that did nothing to change the problem. The only thing left would be the fuel tank itself. Thought being that if there is water in it (since the wagon has been sitting at CCR forever) it would be getting sucked from the tank when we put the car under load and cause the sluggishness and a lean condition? Would it be worth it to try swapping out the tank or is it something else we are overlooking?
October 27, 200718 yr Before you swap the tank out use a bucket or gas can as a surrogate tank to verify it's fuel tank or tank contents related. It sounds like it might be electrical though, and related to the vehicle. What color is the spark? Could be a weird short somewhere or something. GD
October 27, 200718 yr Also EA81 fuel tanks have a drain plug in the bottom. So if you are concerned about the tank contents then pull the plug first and drain it all out. You can pull the sending unit and reach your hand inside to check for sediment or to flush the tank, etc. GD
October 27, 200718 yr put the spacer from the Hitachi on. What?? That's not going to help the man. You don't need the spacer. GD
October 27, 200718 yr oops! been awhile since i done my weber. got it backwards. if it's on, which i doubt since the guys helping you are smart, take it off.i put it on when i first did my weber and it ran like ************. but i did have to double up on the gaskets around the base....
October 27, 200718 yr oops! been awhile since i done my weber. got it backwards. if it's on, which i doubt since the guys helping you are smart, take it off.i put it on when i first did my weber and it ran like ************. but i did have to double up on the gaskets around the base.... Ahhh! you mean he should check for vacuum leaks around the carb base But he shouldn't have to mess with it if it was already on the engine when they dropped it in the car and ran fine before. GD
October 27, 200718 yr reading all the prev. posts in this and other thread, am i correct in assuming that these probs existed with both weber motors to varying degrees but only when in the car transplanted to? i have an idea that i haven't seen mentioned but it's so stupidly simple i'm hesitant to bring it up. i'll go back and re-read again.
October 27, 200718 yr Author "Stupidly simple" is exactly what we need to hear. I suspect that is what is the cause of all this. You are correct in that the problem exists only when the motor is in the 84 wagon (aka. "The Colonel"). The problem did NOT exist with the swapped in motor when it was in the parts car. It ran like a champ...
October 27, 200718 yr its REALLY sounding like either a fuel tank or fuel line issue, or a coil problem. do you have good volume of fuel supplied to your carb? a partially clogged line could cause something like this.. I doubt an issue with the return line could cause it, but it may be worth investigating. As GD said, what color is your spark? I realize you said the coil etc is "good," and I haven't re read your other threads to see what makes it "good" but, the important thing is blue spark out of your spark plugs. Do you have that? You aren't using the same spark plugs as you were in the other engine, are you? Other ignition parts (wires etc?) If so, replace the plugs; I learned firsthand this spring that the most beautiful looking used NGKs CAN be intermittently bad. Failing that... the only thing I can even brainstorm that could effect it would be driveline friction?!!?????? but that makes little to no sense. You HAVE to be close to figuring this out. Good luck, these problems that run from one thread to the next without resolution are the WORST.
October 27, 200718 yr "Stupidly simple" is exactly what we need to hear. I suspect that is what is the cause of all this. You are correct in that the problem exists only when the motor is in the 84 wagon (aka. "The Colonel"). The problem did NOT exist with the swapped in motor when it was in the parts car. It ran like a champ... fuel filters. both of them. there i said it. i have an '84 wagon that was having VERY similar issues.
October 27, 200718 yr Gotta stress, we swapped nearly everything from the silver donor car. The ENTIRE engine with the distributor, alternator, carb+intake which were never disturbed (lines not removed gaskets not removed, nothing). The coil from the silver car fuel filter (vapor separator one). Last night we swapped in the fuel pressure regulator from the yellow car just in case but that didnt help/hurt. Today we will drain and inspect the fuel tank. Thanks for the suggestions guys.
October 27, 200718 yr Just for gits and shiggles....... Run a new ground wire from engine to battery -, Put a length of wire onto coil + leaving other end free', Start engine normally, Hook free end of the wire you put on coil + to the battery +, See if conditions still occur...... If so,,,, you have an electrical problem. Yeah I know, you didn't mess with that much wiring, but it's "old" wiring, don't take much sometimes......
October 28, 200718 yr Author Just for gits and shiggles....... Run a new ground wire from engine to battery -, Put a length of wire onto coil + leaving other end free', Start engine normally, Hook free end of the wire you put on coil + to the battery +, See if conditions still occur...... If so,,,, you have an electrical problem. Yeah I know, you didn't mess with that much wiring, but it's "old" wiring, don't take much sometimes...... This sounds like a good idea, along with changing both fuel filters. We did manage to find some water in the tank when we flushed it, but it didn't solve the problem. Theory being there is still water in the filters...
October 28, 200718 yr Just for gits and shiggles....... Run a new ground wire from engine to battery -, Put a length of wire onto coil + leaving other end free', Start engine normally, Hook free end of the wire you put on coil + to the battery +, See if conditions still occur...... If so,,,, you have an electrical problem. Yeah I know, you didn't mess with that much wiring, but it's "old" wiring, don't take much sometimes...... This IS a great idea.. I have seen ignition setups that for some reason were getting proper voltage, but nowhere near the amperage needed to put a spark out that would actually ignite the fuel; basically we did what tom suggested (this was on a 240Z) and the car cranked up perfectly. Also, swap out a different set of spark plugs if you haven't already; that didn't get specifically mentioned so I had to re-iterate. I'll shut up about it now, but after the PITA I chased earlier this year... I don't want anyone else to go through it. This sounds very similar to the problem I had been facing on my SPFI setup, or I never would've mentioned it.
October 29, 200718 yr Author So remember that thing about "it's probably something stupid"? Remember your mom always telling you to give everything you do a "KISS" (keep it simple stupid)? It turns out that if you hook plug wire one into number three, and the three wire into one, the engine only runs on two cylinders. Who knew... Yeah, I'm the dum-dumb, and I thank everyone for the great advice in tracking this issue down!
October 29, 200718 yr So remember that thing about "it's probably something stupid"? Remember your mom always telling you to give everything you do a "KISS" (keep it simple stupid)? It turns out that if you hook plug wire one into number three, and the three wire into one, the engine only runs on two cylinders. Who knew... Yeah, I'm the dum-dumb, and I thank everyone for the great advice in tracking this issue down! pshaw, that aint nothin. good to hear it was figured out, thanks for the update.
November 9, 200718 yr I have seen Japanese coils give out. They usually end with a loud bang and the car never starts again. With regards to the Weber backfiring, always look at the ignition first check fuel pressure as well. no more than 3 psi
November 9, 200718 yr I have seen Japanese coils give out. They usually end with a loud bang and the car never starts again. With regards to the Weber backfiring, always look at the ignition first check fuel pressure as well. no more than 3 psi Thanks for the advice. The car is no longer in Yeti's posession. He got a brat and may be doing the weber shuffle soon enough.
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