weak spark 79 cressida - Toyota Nation Forum : Toyota Car and Truck Forums

fury67 · 04-17-2009, 01:12 AM

engine is back together,everything is plugged in right but engine wont start, got enough gas, plugs are routed right,timing chain reads proper. but spark wouldnt start a lawn mower its soo weak. car started just fine before but had a blown head gasket. after disassembly and cleaning and sleepless nights putting the 4 miles of vacuum tubing back where they belong the motor came together nicely and is correct in every way. i find it hard to belive the ignitor could be bad and the coil checks out fine. i have a distributor coming in just in case but if i stab a new distributor in and still nothing what could it be? also i cant say if they worked before but i noticed that the gauges dont work at all . the ESP still functions the idiot lights work but no tach or speedo? norelay thta i can find and i took the cluster and the harness is just fine so what now? and yes i hooked the grounds back upp as they came off so i have no idea now. in the proccess i now own the chassis manual the emission manual and the 4m manual maybe ill look for the electrical manual.

stepho · 04-18-2009, 02:27 AM

Sounds like the coil or igniter is wired up wrong.
Do you have a manual with a wiring diagram?

- Stepho

Doctor J · 04-18-2009, 06:10 PM

Not working tach means there is no spark made by igniter. Check pickup coil connector on the distributor.

***kamesama980*** · 04-19-2009, 10:43 PM

How did you check spark?

are you sure the spark is occurring at the right time?

how is the battery? if it's drained it's possible to have enough juice to crank the engine over but when it does so the voltage drop is enough that the computer and electronics don't work. I had an old camry that got like that after it was in an accident and the battery was cracked. started and ran fine for a few months but I'd bought a new car so it was never running enough to charge a good battery much less half of one.

Doctor J · 04-21-2009, 03:52 PM

79 cressida is carburated; the spark is produced by igniter that receives impulses from single pickup coil in distributor

fury67 · 04-22-2009, 09:19 PM

battery is new,i get no gauges at all not just tach, just idiot lights and ESP.im finding it hard to belive that there is no fuses or relays for the engine. ive picked through a corona and supra from 79 and they both have fuses just for ignition. why no listing for my cressy on its fuse cover?names the other fuses but nothing for ign or starter havent found anything for gauges either. ive tested the spark with a OEM spark tester that has one end that attaches to the no#1 wire the other end to a ground. shows the spark jump when you crank the car.btw did just locate a massive book of toyota wiring maybe itll help. waiting for distributor to come in and itll have a new pickup coil in it so when its stabbed in well see where we stand.

Saggio · 05-06-2009, 04:27 AM

Did you get it running?

I have a 79 too!

fury67 · 05-16-2009, 03:34 AM

no not running but i did get another ignitor and ill put that in and see if it will fire.i also found a 78 cressida in the yard thats just too nice to be there i mean were talking premio from the body to the interior.im snagging its console, door panels,all its wiring, emblems,grill[even though i dont need it] dome light lens,instruments. i will grab the front clip on my next payday as undented unrusted sheetmetal is getting harder to find and the wheel well mouldings are shiny perfection. i cant figure why its there unless like mine it was doomed by a blown head gasket or a bad tranny. after prying throught it i can say i belive its stated milage of 78000 the manifold is steel color instead of rust and the A.I.R. injection tubes are still almost chrome like shiny where mine were rust begetting rust.

fury67 · 06-24-2009, 04:36 AM

adjusted the valves and its running but the gas has gone bad and the carb needed to be rebuilt so i rebuilt it and broke a part of it and now im buying another carb for the one piece i need then it will run idle and be happy. guess i should have figured the machine shop ground the valves and gave it a 3 angle job so duh the vales needed adjustment.got a lot of gear off the yard car but they have now erected a fence and said even if a car on the other side was one you could part now you cant why? greed they have to pull it and charge more for it so looks like im done tapping that well.que sera she's running and thats all that matters. oh yea the valve covers look great polished. pics very soon.

rhandwor · 07-25-2009, 07:43 PM

I would check and make sure all ground wires were hooked up after the repairs were completed. Then make sure everything was plugged in after the repairs were done. I've had problems of this type before and double checking for these type of problems corrected them. If it was running before tear down it should start when repairs are done.