10 years after you made this video, you're still spreading knowledge can't thank you enough for the last piece of my electrical puzzle. I appreciate you so very much.
Agreed just went through 20 minutes of U-Tube videos Looking 👀 for the Wiring Diagram on A 1990 Chevy TBI EFI and lots of CLICK BATE ) but you have the BEST information ℹ️
(95 1500 tbi) when all else fails, check the tach wire at the coil for ground.. If it has constant ground, a quick fix to get ya rolling is to clip it. The coil is signaled by ecm through the other white wire found in the second connector on the coil and these 2 splice into pine another inside the coil. The tach wire is finding a ground (i haven't began my search for it so ill try to get back here with an update) and that ground is trying to energize the coil anytime you hit the key and with enough time burns up the coil.. So if clip the wire orfix the ground, but still no spark.. Test your coil that you've likely just replaced or had replaced.. Hope this is helpful to someone nonethless
What's up everybody, I have a 95 Silverado. Kinda had the same problem, I put a towing cam in it this past summer and the computer went nuts trying to figure out what to do. I racked my brain for a week or so till I watched this video. All I had to do was unhook that single wire plug( 95 is under the dash on passenger side) and leave it unhooked set my timing and let the icm do the job. Runs like a champ
Wow! You just pointed out what should have been obvious to me! I forgot all about the timing wire bypassing the computer. This will tell me right away what my problem is
I have a 1991 k1500 5.7 did a complete tune up except coil, ran great for 100 miles, now experiencing a flat out no power situation, runs rough idle and can not pull a hill or gain speed at all except over time. I can put my foot into it and sometimes it will act normal until I take my foot out of it but than it acts like not running in all cylinders. Oh yes revolution the throttle body as well thanks Don
This could also be caused by a bad pickup coil in the distributor. I believe autozone can test the ICM but don’t buy one there. Get it from a higher quality supplier like NAPA.
My husband has 98 Sierra he has changed everything,hoping this is his problem...will turn over but won't fire...we had no clue about an ecm,until this web search,hes outside ride now hunting down that black tan wire,trying to do what you said for retiming... praying it works..thanks alot for the video
Good advice,.... i have a 93Sierra that never stalls but often will not start do to no spark...then one day when it feels like it she'll start ! Should of never gone away from good ole points !
Haha, well I do agree that the ICM is a finicky module and it does not like heat at all. Don't buy a cheap one either or it will not last long. I doubt OEM modules even exist nowadays though :(
i believe if you crank it and have fuel pressure out the injectors the pickup coil in the distributor is good.....went thru this on my 92 astro....thought i had bad coil but it was the ignition control module that was junk...the module sends a signal back to the coil to spark so dont assume its bad coil right away..
Get a Actron CP9690 code tester. It checks live, record, graphing, emissions readiness test, oxygen sensor tests, ABS, SRS, and MORE! It retains the memory of results. There's another without the OBDI cables and it has the same tester. It comes in a black pouch. It has a cigarette lighter adaptor. Out-of-the- box it tests from 1984-2013. It is updatable with a USB cable from EBAY. It comes with OBDI cables for Ford, G.M, Chrysler, and Toyota, and a OBDII adaptor. There are penlight batteries under the cover at the small screw. It is well- lit! EBAY has it.
Thanks for this I just had to put new coil connectors on where someone had cut them off my 87 v20 and had a old school coil on it so I put it back factory.
I have a 92 gmc k1500 350. Only thing I have not replaced was the Ignition Control Module Relay. I ordered it see what that does. Currently it acts like no vacuum advance. It cuts out won’t pull. I had a pulsing idle replaced the knocks sensor that solved that I’m almost at 100 percent now. I’ll put that Ignition Control Module Relay in see if that’s it. I changed the cap and rotor wires and plugs. New coil as well. New ecm new computer. I bought this truck brand new so only the Ignition Control Module Relay hasn’t been replaced. Can anyone give me suggestions please?
If you fellas cannot find the brown wire, look under the passenger side dash inside the cab. Brown wire with black stripe. I have a 1994 k1500 5.7L that I am restoring and mine was behind the glove compartment next to the computer. It can also be closer to the floor behind the foot-well light, by the carpet and blower motor. To set the timing: Unplug the wire turn on the truck and wait for the engine to warm up find Top Dead Center (0 degrees) on #1 sparkplug turn off the truck reconnect the wire turn truck back on, and the computer will set the advance (usually 20 degrees) Drive around a little bit afterward, because the computer will learn as you accelerate and slow down and further fine tune the timing
cccalhoun I have a 1994 GMC pickup two seater I think it's a Stepside and I have the same exact problem and I got everything and nothing is doing the trick. It'll drive for a few days as soon as I buy a new battery and then it just dies and I think that's the problem is the brown wire. But I don't understand what do you mean turn or go to the number one spark plug and 0 degrees? And also so you're saying I can go behind my glove compartment which I already found all those other relays and change them so I can find the brown wire there undo it then I could turn my car on and then turn it off find the one spark plug and do what how do you turn it through degrees what do you mean by 0 degrees I don't get it I really appreciate all this information I've been looking on RU-vid for 2 weeks and on the schematics and everything you can think of especially being broke
cccalhoun or is that too just set timing I still don't get it do I do all that first the bypass does starting point because my truck won't turn over are you saying unplug the brown one and my truck will start and then do it all over again for the timing can you give me a detail I know you don't know me I would appreciate it
Buddies truck has an issue and we don't know where else to look! New cap rotor coil ... Cranks gets fuel does not fire but will fire with a small shot of starting fluid.
I had the same issue several years ago. It was the pickup coil but I just replaced the entire distributor. It was easier and cheaper than just the coil.
Hey farm boy I've been watching your videos for awhile I have a 94 C 1500 4.3 on the passenger side just laying on the intake there's a female plug with solid purple and solid blue wire going to it from the harness but it's not used someone told me it was for the service techs to check RPMs at factory if so I should be able to get another pigtail and wire a tach into that plug correct
I have the same thing laying on my intake Jonathan... Did you ever find out what it was for? I suppose Google search for a wiring diagram could tell me but curious if you found your answer
Where is the Electronic Spark control module located on 1993 Gmc Sierra 4.3 6 cylinder? The book we bought says near the throttle body or behind the distributor mounted to the fire wall. We can't seem to find it
I've got a 89 k1500 with no spark. I've put an inline tester on 2 different plugs and it flashes once when I turn the key on and nothing while cranking. I tried the bypass you showed and still no spark.
This could be my issue... mine is a 90 Chevy 350. Replaced three coil module 3 times, last one with ACDELCO. Still isn’t starting. I’m gonna look for this computer wire tomorrow. Pull it... crank it... and see what happens.
i have a 92 s10 pick up and this may be my problem, i changed the coil and cleaned up distributor but still randomly starts, I'll try ti unplug the brown wire you pointed out and see if it helps, thanks
It should still crank with the ICM before swapping to the ECM. The brown wire connects the ECM to the distributor. The only time you should have to disconnect the brown wire is to do the initial timing.
Just looked at your video I got a 1994 chev 1500 Cheyenne I haveing trouble some times it will start and run when not in gear then I put it reverse and it will cut off and don't want to start no more I would have to put gas in the carberrader to start .. can you help me with this problem..
Have a 1994 chevy 1500 the timming is ok put a new coil on heard at arcing noise it's arcing where the two plug wires plug into the coil only arcs every so many seconds. At the top of the wires
I'm having a starting issue, I have a 94 1500, I replaced the motor with 1 out of a 89 model, new plugs and wires are on it!! If I were to do this would this be the culprit?! I did not replace the computer or anything! Its spinning over but wont turn over for me. Any ideas would be appreciated!!
Yea I change fuel pump ,injecters,ignition module , thinking it was that . nothing so then we went and check the grond on the injecters and no spry so that's the issue . I tested it by touching on any ground and spayed.. but how can I fix this problem... i really appreciated your help ...
solid angel did u find out whats wrong ? i have same issue. lots of new parts pump. injectors. distr. n ign. all of a sudden i crank and no spray whats going on?
thanks this is helpful i still aint got no spark after doing all the same mess its a 1996 454 in a Winnebago i wonder how to set the timing or if i need to also can i set it without running by just cranking?
Not sure if anyone is checking this still. Got an 87 gmc sierra 1500 with dual tanks. Stopped while driving. Fuel pump would intermittently turn on. Replaced with a new one and new filter. Turned on once and now does not. We tested by hooking up to a power source and it works. Checked all connections with test light. Engine has spark but no fuel will produce through the TBI due to the fuel pump not kicking on. This is the driver side tank. Passenger side did not work when I bought the truck. Suggestions??
Check the fuel pump relay. If that's ok, then check the oil pressure sending unit. Power to the pump is initially through the relay via the PCM then once oil pressure builds it is powered through the oil pressure relay.
I have a 1991 chevrolet k1500. I changed my throttle body gasket and started the truck up and noticed a minor leak so I shut the truck off. After I tightened the hose I went to go start the truck again and had no fire. I changed the cap and rotor and cleaned the module but still have no fire. Having trouble find the brown wire but I was wondering if you may have an other idea to why I would not be getting fire?
Please help -Ok I have a 88 with the same coil - on the side with the thicker wire -the wire wire comes out of the plug that goes to the cap that plugs into the coil comes out and is cut - it’s Allways been like that - where is it supposed to go 🤷🏾♂️
I gotta question I have 92 chevy k1500 after tightening thepower wire to the ALTERNATOR my fuel pump wires burnt I replace the wires where the burned a little that issue resolved but while doin so I hooked them straight to the battery to test the pump it still work UT after wiri g it back correctly I have no cli king no spark absolutely nothing when I turn to the key to try and crank the the truck
i have an unrelated question. i have same setup, recently had to replace ignition module under distributor cap. its run fine for a while, until starting up a hill the other day and all of a sudden got a loud rattling clanking noise from engine, and loss of oil pressure down to half (20) instead of 40. any ideas? the top side looks good all rockers move good, bottom side looks okay as far as i can tell, didnt get anything out of oil pan. whats your suggestion
Doesn't sound good. Loss of oil pressure sounds like a clearance issue. Maybe spun bearing? I'd definitely want to pull a couple of bearing caps off and look. Good luck.
@@solutionscalebgearheadz5204 I would look for a bad ground if gauges are acting weird. I assume it's pouring fuel into the TBI? Like the injectors are stuck open?
I got a 93 Chevy 3 quarter ton TV I crank it up fine but when you started driving it won't like it's not getting no gas and I don't want you don't have to keep pumping accelerator to keep it going and it won't be let off it goes dead
I'm hoping you can answer this. My truck has a rough idle like it's not advancing the timing. I have done cap, rotor, coil, ignition control module and even the distributor at this point. When we unhooked the wire to set the base timing the truck dies. It show's a code 42 which comes up as ignition bypass circuit error.
hey great video you explain things very well that help so much! so my truck 89 chevy 250 it seems to run well but limps around 55 mph and doesn't want to go faster pulling a light boat. so i checked codes since the light came on and they read 32 and 43. the 32 says map sensor and 43 is bypass ignition signal failed. what's your opinion here. i was going to get the map sensor but what do i replace for 43? thanks again for the help you give.
I have a 94 Chevy suburban k1500 350tbi and the ecm fuse keeps blowing randomly and can’t figure out why it only does it randomly wondering if you have any insight on how to trouble shoot it
Great video, but I can't figure out why my 95 GMC Sierra sometimes runs great but when you kill it it's lible to not crank again for a week, sometimes I can pull it off but it's got me puzzled any answers?
Good info. Thank you. I replaced the complete distributor,coil,cap,rotor,plug,and plug wires. Set timing and started up. Set base timing. Shut off truck and will not start back. Any ideas ?
Truck just stalked while waiting for passenger to get out of truck. Acts like it wants to stall while driving on freeway. I keep my feet on gas and it picks back up new fuel filter, new distributor what's wrong with it?
I have a question 97 350 try and find out where the white wire goes to come off of the have a red wine or white wine and another red wine I'm trying to figure out where this white wall coming up the call
Is there supposed to be battery voltage from the coil to the icm? My 1991 chevy 5.7 decided to not start last night. No spark. Replaced the icm hoping that would solve it. Now I'm stuck.
@@Michael-wk4yo Kind of funny this came up. Last few week, my pickup was running like crap. Getting crappy fuel mileage. Apparently I didn't put loctite on the distributor bolt when replaced the distributor. It backed out and slowly spun my distributor. If your pickup coil is bad and you replace your distributor, make sure you use loctite on that bolt! Good luck!
What if it stalled randomly distributor bolt loosend up and no spark after put a new distributor in now I have spark and fuel but still won't start trys to
1990 Silverado, 5.7 all lights on dash work when turning key to on, try to start and nothing, starter wont rotate but still powers everything. tried two brand new starters, same problem. one day it starts, sometimes it doesnt at all. Any suggestions?
Could that why effect it on start up? I had to change my oil pressure sending unit and when I put my distributer back in timing was right but on start up it wants to die right away but if you give it alil gas and let it idle at about 2000rpm for about 30seconds then it's okay.
When you timed the distributor, did you unplug the wire so that the computer wouldn't effect the timing? Not sure, but it sounds more like a problem with the Idle Air controller.
Quick question. I have a 94 Silverado c2500 with a 5.7L. If I use starting fluid it starts and runs fine. No starting fluid it just cranks till the cows come home. This started after using engine degreaser and power washing it off. It started fine after the spray and I let it run for a bit to dry everything up. Was looking fir an oil leak. Any help would be greatly appreciated.
@@farmboy30117 Ok, so replaced the fuel pump relay, same issue, reset the computer and it was flashing code 21, read about it... cut a hole in the bed and replaced the fuel pump... not the problem... Its a long bed so was not able to lift it myself and I filled the tank like a day before this started... Today went and got a fuel filter and a new TPS... Replaced both of them and now it works fine, my code 21 is no longer there so guessing it was the TPS that caused the issue. I can honestly say after reseting the computer the idle is perfect now and it even seems to run better! Thanks for your help man very very much appreciated!
Farm boy I need some help I just bought a 89 Chevy Silverado 350 four-wheel drive and I have no idea what to do I'm having the same issue to start no crank no spark and my battery terminals getting hot when I try to turn it over help please..
Ok thank you very much for your kind answer, the dealer has the new pickup coil and also the distributor cap and rotor, will hey have to change the distributor shaft?
I have 94 GMC tbi 4.3 v6 vortec, was driving it, shut down like u turn key off no back fire, pop, no noise, I've checked it no spark, will crank but want start, what's my troubles, also have just replaced cap button an wires (+spark plugs) took ingintion modugel off had it checked an was good
I have a 1991 K1500 350. I was driving down the highway last night and it started sputtering then died. It has been stalling out the past few days sometimes when I am in gear and stopped at a light or if I drive at very low speeds. I smell fuel when trying to crank and we sprayed some brake cleaner in the top. Changed the control module in the distributor out with a known good module still the same. We noticed that the spark in our tester was very orange and dim, it usually is bright blue. There was some dirt on the contacts inside the distributor but we cleaned them off and the spark plugs looked OK but probably need changed soon.. but still should be operable. Any suggestions? The motor, distributor cap and entire distributor motor is less than a year old.
Well it's either going to be fuel or ignition related it sounds like. I assume it cranks right back up? Have you changed the fuel filter recently? No codes?
When we use our spark tester (small tube put inline with the spark plugs), the spark is very dim. It is normally a bright blue color. We have replaced the entire distributor module and I swapped out the starter with a new one just for good measure because I have a lifetime warranty on all of the parts. It still will not start.. the only thing I think I can check for is to see if it has an ignition relay thats gone bad or the ignition switch itself is bad. Why would it have a weak spark?
