1988 Chevy Truck No spark at plug

Remove distributor cap and have a helper crank the engine for you as you check if the rotor
rotating
if not remove distributor and check gear and also check timing

[quote:4730c195fb="BMRFIXIT"]Remove distributor cap and have a helper crank the engine for you as you check if the rotor
rotating
if not remove distributor and check gear and also check timing[/quote:4730c195fb]

The rotor does rotate while cranking. How do I check timing if the motor will not run?

Can you clarify some thing for me
with engine cranking you have no spark you moved the distributor and you have spark know put no start
is that correct
or you have no spark at all
do you have spark at the coil
check coil and connector
one way to check if the rotor and crank shaft timed is to put the crank shaft at top zero center
check if rotor at or close to # 1 spark lug wire at the cap

[quote:472710a712="BMRFIXIT"]Can you clarify some thing for me
with engine cranking you have no spark you moved the distributor and you have spark know put no start
is that correct
or you have no spark at all
do you have spark at the coil
check coil and connector
one way to check if the rotor and crank shaft timed is to put the crank shaft at top zero center
check if rotor at or close to # 1 spark lug wire at the cap[/quote:472710a712]


That is correct. When I turned the distributor and sparked I had the engine crank several cycles and the plug would not spark again until I turn the distributor again and repeated it a few times.

I would pull the distributor and look at the gear, sounds like it may be partially worn out
Could also be a bad ignition module, they were known to fail

You can read guide below, it will help you with your no start condition

https://www.2carpros.com/articles/car-cranks-but-wont-start

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Ok this has been bothering me for a while now. I replased the engine about a week ago and everything is fine no problem at all except to intermittent codes for lean air mixture. today i come out to start it and it cranks but doesn't have any spark and no injector pulse. i have 12 psi of fuel and when i disconnect the 4 wire connector from the back of the distributor and take a test light that is connected to 12v and touch the connector terminal that is a reference wire for the ecm, the injectors shoot fuel out. i have replaced the ignition module and still have no pulse and no spark.

OHM check pickup coil see diagram

A infinite resistence in B 500-1500 ohms

There is no spark at the plugs even after replacing ignition module, dist. cap, rotor, and ECM. There is spark at the coil. The main reason why I changed the ECM was ALDL gives no response when a scan tool is connected but does flash a code 12 with the servise engine light (still nothing with the scan tool connected) This all started when in the morning I started the drove it 10 miles stopped got gas started right up drove it another 10 miles to a store came out 15 minutes later and it would just crank and not fire up. I would appreciate any suggestions of other areas to check.

Hi tdecker85087 and TY for the donation

Check and test the distributor pick-up coil and air gap-also double check the cap and rotor contacts-if there's spark out of the coil-it should have spark at the plugs if cap and rotor good it has to make it out there to get to the plugs

DTC's

12
No Distributor pulses

13
Oxygen sensor

14
Coolant Temp sensor circuit

15
Coolant Temp sensor circuit

21
Throttle Position Sensor

22
Throttle Position Sensor

23
Manifold Air temperature sensor

24
VSS (Vehicle Speed sensor)

25
Manifold Air temperature sensor

32
EGR system

33
MAP sensor or MAF sensor depending on engine

34
MAP sensor or MAF sensor depending on engine

35
Idle Air Control Valve

36
MAF Burn-off circuit

41
No Distributor pulses, cylinder select error

42
Electronic Spark Timing or Bypass fault

43
Electronic Spark Control fault

44
Lean exhaust

45
Rich exhaust

46
VATS system fault

51
PROM fault

52
CALPAK fault

53
System over-voltage

54
Fuel pump circuit

55
ECM fault

61
Oxygen sensor fault (degraded sensor)

Electrical problem
1988 Chevy Truck V8 Four Wheel Drive Automatic

I wondered if anyone could help me with a question that I can not seem to get a answer to. I have a 1988 Chevy 350 TBI K1500 truck and need to know could a defective ECM cause it to have no spark. I have fuel out of injectors,power to the coil. I have replaced the coil,ICM and it has a whole new Dist as of 6 months ago. Timing is good also just set it and confirmed the rotor is turning when motor is cranked. Problem started where it would cut out and surge at low-mid rpm but if I gave it more gas to where it would go into passing gear it run really good,but as soon as rpms dropped down it would start surging and cutting again.Then i was getting on the freeway and to stop it from cutting out i gave it about 3/4 throttle and it kicked a couple times and shut off.Now it cranks fine but I have no spark. PLEASE IF YOU CAN GIVE ME YOUR THOUGHT ID REALLY APPRECIATE IT.
Thanks A lot

Welcome to the forum. Is there a pulse on the negative/tach side of coil, use a testlite? Any codes?

With bypass ignition, it is the ignition module that controls spark under 400 rpms. Over that, the ecm puts 5 volts on tan wire with black tracer. That signal tells the icm to use the signal on the white wire for spark timing. If signal on the tan wire and none on the white, there may not be any spark. Whether the problem is the wiring circuit or ecm??

Electrical problem
1978 Chevy Truck V8 Two Wheel Drive Automatic
----------------------------------------------------------------
My 1978 chevy truck just stopped running today. Upon checking I found that it was getting fuel but had no spark. Replaced the coil, cap, and roter. Still no spark. Any ideas of what may be wrong?

Make sure the distributor is getting power from the igniton switch-if so all you got left now is the ignition control module/and distibutor pick-up coil

take the number one plug out leave spark plug wire on and crank engine and look at electrode to see if spark coming from it use proper rubber end spark plug pliers

forgot to mention the number one plug is on the drivers side cylinder closest to the power steering resevoir (front)

I bought my Chevy a little while and it ran like a tank. than one day it wouldn't start. it did have a weak spark and gas when it first died but now it has none. i repalced the distrubitor cap, coil, oil and air filters, ICM, spark plugs and the cap wires look good. my thought is if the fuel pump died wouldn't i still have spark? I really am stumped any advice??

My info shows your vehicle is fuel injected. Without the rpm signal, there won't be any spark or injector pulse. The rpm signal comes from the ignition module,but, without the trigger signal, the module doesn't know what to do. The trigger signal comes from the pick-up coil assemble. I'm not telling you to replace anything, right now I'm not quite sure what's causing your problem? Is there B+ at the coil, with the key turned on? I have seen procedures for testing the circuits to this type coil,but, my memory fails me.

As far as the fuel pump, my info shows there is an oil pressure switch in the fuel pump circuit. After you crank the engine enough to bring up oil pressure, that switch closes, and the pump will run, but, it doesn't matter if the pump does run, cause without the rpm signal, the injectors won't pulse.

I recplaced the coil, had the ignition module checked, ok. getting a reading of 1300 ohms from the pick up coil. No spark at the coil wire.

I removed the pick up coil it was melted pretty bad, the ignition control module was going bad, tested ok but it finally failed. Now i cant get it timed correctly when i reconnect the EST the truck will not start, but when its disconnected it will run fine. :?: Whats next?

Maybe someone can jump in on this :)

The computer will switch to a default parameter or value if a sensor is whacked. The adjustemtn will keep things working on a temporary basis.

do you think it would be ok to drive this way? Temporarily?
Is there anyway of resetting

Brother, I'd love to give the right answer, but I'd be letin' my ego take over my brain :(

My "guess" is yes. Strongly encourage to send a PM to one of the other moderators. 2carpro Jack is very good :wink:

92' chevy c1500 5.7 tbi hei remote coil new motor new distributer new coil new esc new ecm all fuses good all grounds good no spark no fuel hav voltage to coil engine cranks great

how can i get ahold of 2carpro Jack? cant find out how to send him a PM. can ya help?

Test fuse links at battery junction block also check for voltage at ECN terminal B1 and C16

Right above the Reply to question button on top of the page there is your topic and above that is "GO BACK" . Cleck the "go back" and you'll see the moderators, click on his name and there is a PM button in there.

Also test the ICM and distributor pick-up coil-

My father a 1989 Chevy Truck with a 350 engine, maunual transmission and 250,000+ on the speedometer. He sudenly has a no spark and no fuel to TBI problem. The engine cranks over so not a battery problem. I checked and replaced his dist. cap., coil and the ignition moduel but still no spark and still doesnt uncover why there is no fuel going to the TBI though the fuel pump is working. I am thinking the ECM went out yet need another mechanics opinion. Thanks for any additional ideas on what is causing this.

Three things,

1. Fuel pump fuse- passenger side firewall in a fuse holder

2. Fuel pump relay- next to fuse

3. Bad oil pressure switch possibly will cut fuel to TBI

Check these

What is the general part that fails on this rig? My truck runs perfect but every once in a while there is no spark...then suddely bam....it will start. I believe the coil is failing or somehting in the dist. I have heard about one electrical part in these older chevys that work intermittently then finally completely fail but I need some help.

From my experince with no spark problems, You may want to do these trouble shooting first:

1.How long has it been since you truck has had a complete tune up, Plugs / wires / dist cap / rotor / coil pack replaced?.

2.Could also have a problem with youre ignition Module thats located inside youre dist area.

3. Could have a dist itself wornout.


Hope these tips help you out.

Good Luck.

our truck is having the same problem we have replaced the engine, transmission, carb, distributer, intake manifold. gaskets, fule pump timing chain and gears, fule filter, spark plugs, wire harnes in dash, and more some times it will start adnd sometimes not. we are soooo tired of this truck. it wont start in the morning but it will in the evening or when ever it feels like it. it was dieing when we were driving it it has been in 3 shops no one can find problem they are all just having to guess please help!!!!!

For both of you-try checking the coil and ignition control module. Also the ignition switch when it heats up breaks open no power to the ignition system.