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| really strange engine surging with lights on | |
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| Tweet Topic Started: Apr 12 2014, 12:18 PM (509 Views) | |
| espltd | Apr 12 2014, 12:18 PM Post #1 |
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Tinkerer
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Hi all first off want to say this is my first post here, been browsing your site for the last few days and very impressed with all the helpful knowledgeable folks on here. Anyway I m a recently new owner of a little 98 3/5 with about 220 k miles that I picked up for 400 $ Engine was rebuilt at 180k with the paperwork, and when I bought it it needed a clutch which leads me to my question. The clutch install went easy no probs and since I noticed that the bearings were getting a little noisy I went ahead and rebuilt the tranny while it was out ( many thanks to pacpao and the other authors of your transmission rebuild series for help in getting it all apart easier. ) Upon reinstalling and starting her up the idle was really odd almost like it was flooding out or running too rich, and wouldnt stay running too long. Checked the EGR it was ok checked all my grounds and cleaned them, the one on the throttle body seemed to make a difference and I thought it was the solution. No now it runs fine in idle regardless but if I turn on the headlights and roll forward the engine starts surging, even if it isnt in gear rolling forward, turn off the headlights and back to normal. Pulled the light relays and problem seemed to resolve, disconnected the DRL module and it got much worse. Also just discovered the heater switch isnt working now either, all of these things worked perfect before that transmission work. This is by far the strangest problem I have ever encountered in car repairs, I saw a thread here talking about the diode module being a possible suspect but never really saw any resoloution to that problem, nor do I know much about diode modules. Does anyone have any ideas or did I just bugger up one of the wiring harnesses and need to tear it all back apart ?? Any help is much appreciated Update... Took all the grounds off again for a good cleaning now the car really won't run at all. Just sputters pops and dies, seems like it is connected to the grounds on the back of the TBI, I actually went and replaced the entire tbi assembly with a known good spare and nothing changed. So it leads me to think something in the harness, buy I'm not really the best on the electrical side. Anybody have an idea ? |
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| Hanuman | Apr 12 2014, 03:28 PM Post #2 |
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"The Almighty Grounds Cleaner"
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re-do those grounds, again. check for damaged/loose/corroded conections. it ran better before you cleaned the grounds, your answer lies hidden in the grounds. fix |
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| Hanuman | Apr 12 2014, 03:36 PM Post #3 |
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"The Almighty Grounds Cleaner"
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Surging idle/loping idle if the idle does surge up and down while at idle and with a fully warmed up engine, (drive for 20 minutes) then heres the next step...... i just fixed my fast/loping idle a few days ago. mines a 1997 3/5. lets start with the easiest things to check, and work your way on.......(i kinda wish i had done it this way....) 1# is it a vacuum leak or something else? you can check/replace every vacuum line on your car....spray it with flammable liquid and risk setting your self on fire.....or you can watch the ISC plunger and see if its pushing the throttle in and out with the fluctuations in rpm. no plunger movement? vacuum leak. plunger is moving throttle? not a vacuum leak.....move on to .... 2# are the throttle body coolant lines plugged? with the engine nice and warm on the passenger side of the TB you will find 2 very small coolant lines....they should be as hot (both of them) as the heater hose lines. if not disconnect both lines, use your air compressor to blow all the junk out. (make sure you insert the blow nozzle through the TB side of the line, i wasnt paying attention and got a free coolant both, its also a fast way to remove half a gallon of coolant. takes about 2 seconds) if the lines are BOTH hot....move on too.... 3# clean your engine grounds. even if they look clean, disconnect and clean the grounds, use a dremel tool, sand paper what ever. make everything shine! your car will thank you for this. period. just do it! ...........A# the ground wires on the back of your intake manifold VERY IMPORTANT! ...........B# battery cable ground to tranny. ...........C# battery cable ground to chassis near top of radiator. also there is another ground behind the engine fuse box. on the inside fender. ...........D# distributor ground. black wire with a clip in the middle. runs from below the distributor to the coil on the fire wall. clean distributor ground. remove coil and clean wire mounting point, and clean where the coil bolts to the firewall (both fire wall and coil) 4# the throttle stop screw. this is not a idle speed adjustment! back it off until it doesn't touch the throttle. (this was my problem) did this work? adjust throttle stop screw correctly (directions are on the forum, Google it) not the problem? adjust throttle stop screw correctly (directions are on the forum, Google it)...see the next one 5# adjust your TPS. this is complicated go to the "guides and how to section" and look for "THE TPS REPORT" by badbent. and adjust. |
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9:12 AM Jul 11