Ready to kill something, Car still bucking EFI issue with 1.8L |
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Ready to kill something, Car still bucking EFI issue with 1.8L |
qa1142 |
Jun 22 2005, 07:48 PM
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#1
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
Ok,
I have cleaned contacts, tested at computer connector tested MAF, checked head temp, checked fuel pressure, Did it with points, now have compufire, still does it Changed coils Cleaned grounds Changed plugs Tech tips 700 says throttle position switch on 1.7 and 2.0 can cause this. Could the one on a 1.8 do it? I have spair. Someone help me (IMG:http://www.914world.com/bbs2/html/emoticons/icon8.gif) |
qa1142 |
Jun 22 2005, 07:51 PM
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#2
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
PS: I have a copy of Volkswagen USA Course manual 4.02
"Fuel injection AFC Air Flow Controlled" Still cannot figure this out (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif) |
grantsfo |
Jun 22 2005, 08:00 PM
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#3
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Arrrrhhhh! Group: Members Posts: 4,327 Joined: 16-March 03 Member No.: 433 Region Association: None |
No vacuum leaks anywhere, right? Oil cap sealing well too?
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qa1142 |
Jun 22 2005, 08:03 PM
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#4
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
Vacuum leaks fixed last year.
removed Decel valve. all new hoses, double checked with ether for leaks. all AOK O yeh, tested thermo time valve, no leaks after the couple of seconds it takes to close |
scotty914 |
Jun 22 2005, 08:07 PM
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#5
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suby torque rules Group: Members Posts: 1,525 Joined: 20-July 03 From: maryland, the land of 25 year Member No.: 924 |
when you tested the maf did you put an ohm meter on it and move it thru its range to check for a dead spot, then you might as well change check the tps ( i think it is just a wot switch but check it any way )
if the stumble is at one rpm i would check the dizzy to make sure it is not sticky in any spot how violent is the bucking, a miss be it either no fuel or spark is violent. now if you are loosing fuel the l jet does all 4 cylinders at once for fuel so if it is fi it should be accross all 4 cylinders. have you changed anything before this started like plugs or spark plug wires, you can have a bad plug wire and have it intermentant. also how is the rotor and cap. |
grantsfo |
Jun 22 2005, 08:07 PM
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#6
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Arrrrhhhh! Group: Members Posts: 4,327 Joined: 16-March 03 Member No.: 433 Region Association: None |
I'm going for silly stuff. Fuel filter clean?
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qa1142 |
Jun 22 2005, 08:13 PM
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#7
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
Fuel pressure is good, so filter should be OK - new last year - cleaned screen in tank when it was out this winter
I did check the AFS at all steps. My course book gives rating at every step (position) and it tested fine. |
qa1142 |
Jun 22 2005, 08:14 PM
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#8
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
BTW
Fuel filter is not that silly, but I have learned that lesson on my 64 chevy in high school (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif) |
qa1142 |
Jun 22 2005, 08:18 PM
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#9
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
Tach reading stays steady, so spark is still there
I think I am dropping all 4 injectors, sometimes just enough to buck, sometimes long enough for car to decelerate for 8-10 seconds. First it happend once mid summer last year Went weeks fine, slowly became more frequent as year went on. Now it is every time I am out (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) |
JerryP |
Jun 22 2005, 08:21 PM
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#10
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member Group: Members Posts: 314 Joined: 8-October 03 From: Berwyn, PA Member No.: 1,225 |
Even sillyer.....I had the same symptom with my 2.0. Cleaned some crud out of the tank....no more bucking (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)
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lapuwali |
Jun 22 2005, 08:42 PM
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#11
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Not another one! Group: Benefactors Posts: 4,526 Joined: 1-March 04 From: San Mateo, CA Member No.: 1,743 |
While we're into silly, make sure all of your injectors are plugged in securely. I had a single (1) injector connector come loose on a Golf a few years ago, and the car would randomly buck like someone was cutting off the ignition asthe connector would make and break the connection. I believe Nathan had the same thing happen to a D-Jet 914 awhile back. It would cut out in hard turns, where the connector was pulled away from the injector.
Does it only cut out while you're driving, or does it do it sitting in the driveway, too? Is it tied to load (does it more up a hill than down one)? |
qa1142 |
Jun 22 2005, 08:52 PM
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#12
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
does not die at idle and does not feel or sound like it is missing
Bucks accel, decel, and just crusing goes days fine (not this year) Then bucks every time I drive her. Fine for few miles, bucks couple, fine again Sometimes is non-stop where I worry if I'll make it home (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) |
ClayPerrine |
Jun 22 2005, 09:14 PM
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#13
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Life's been good to me so far..... Group: Admin Posts: 15,508 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille |
Check the dropping resistors. They are mounted to the chassis, and the harness connects to the engine. Because the engine moves a little bit relative to the chassis, the wiring in the resistor packs have a tendency to break. There is one common wire that feeds all the resistors. If it is flaky, you will get fuel cutout. I have seen this same thing.
Start the car, and wiggle the wiring on the dropping resistors. Otherwise check the grounds under the intake plenum. |
914GT |
Jun 22 2005, 09:56 PM
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#14
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Senior Member Group: Members Posts: 1,100 Joined: 11-October 04 From: Tucson Member No.: 2,923 Region Association: Southwest Region |
Check your timing for too much advance. Make sure the distributor advance mechanism is working properly, it may be worn out.
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elwood-914 |
Jun 22 2005, 10:21 PM
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#15
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elwood-914 Group: Members Posts: 387 Joined: 29-December 02 From: Plymouth CA Member No.: 38 |
Check your F.I. contacts inside the distributor,mine was bucking and checked it and it was badly pitted. No more bucking.
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qa1142 |
Jun 23 2005, 07:32 AM
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#16
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
L-jet has not contact points
I'll check timing and for loose connectins toninght (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) |
redshift |
Jun 23 2005, 07:37 AM
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#17
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Bless the Hell out of you! Group: Members Posts: 10,926 Joined: 29-June 03 Member No.: 869 |
I have never owned a 74 1.8.
I recently had a somewhat similar problem with my 74 2.0, that went away when I cleaned, and reterminated wires in the harness connections under the passenger seat, and taped the seatbelt interlock rig together with better tape than the PO.. (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) I dunno... M |
Michael J |
Jun 23 2005, 08:03 AM
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#18
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Welcome to 2007 Group: Members Posts: 268 Joined: 23-November 04 From: Olympia, WA Member No.: 3,166 |
My 1.7 did this when cruising at constant speed. Throttle at nuetral position. Under acceleration it was ok. Started fine, idled fine. I finally took the TPS switch apart and it was full of "crude". A technical term. Carefully cleaned all the contacts and reinstalled. Problem fixed.
Yours does sound like a broken or loose wire. Hard stuff to track down. Good luck & keep the evaluation results coming. |
qa1142 |
Jun 23 2005, 08:53 PM
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#19
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Whiplash Group: Members Posts: 1,514 Joined: 1-June 04 From: Lake Zurich, Illinois Member No.: 2,140 |
FYI
Head temp sender was bad, Thanks to Brad Mayer (914LTD) for the suggestion She's purring (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/wub.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/mueba.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/aktion035.gif) An then some See you on the trails |
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