89 gmc I have spark and fuel but wont start

SOURCE: engine won't start

when you pulled the dist did you mark it before pulling it and were ALL the timing marks lined up
if not you will need to pull # 1 sparkplug and get the piston up to TDC (top dead center) on the compression stroke then put the dist back in with the rotor pointing to # 1 plug wire .
Be sure to check dist direction of rotation and comfirm firing order

SOURCE: my 1989 gmc 2500 sle sierra wont start iv replaced

Check if there is power going to the distributor

SOURCE: I have a 98 GMC

maybe the fuel injectors

SOURCE: 1994 GMC K1500. Ran great,

As per the problem which you mentioned in your question it says " Once it gets up to op temp, idles very rough, won't take fuel, eventually dies. Won't restart til cold."------- ------- Its low fuel pressure or problem with o2 sensor.----------

As per your problem mentioned, it indicates the problem with fuel pressure.-------- The fuel pressure is low.---------- First thing you can do is get the fuel pressure checked, this will confirm the problem. --------- If the pressure checked low that means problem is with faulty pump and clogged fuel filter.----------- If the fuel pressure is checked ok, then other possibility is faulty o2 sensor and crank sensor. The o2 sensors are before and after catalytic converter.-------Both the sensors are to be replaced.------ And as per you mentioned your problem, its quite possible that faulty o2 sensor will cause this problem.------ O2 sensor is the part which sends signal to ECM( the cars computer).It sends signal to computer about fuel / air mixture.How and when to send fuel to engine.--------- If o2 sends stops sending signal to cars computer then it will not send the fuel to engine.------- In your case the o2 sensor is getting overheated and this is stopping the o2 sensor from sending signal to ECM.But when your car shuts off the sensor gets cool and again it starts working.------ So as per problem, get both the o2 sensors checked and replaced.---------- Also get the crank sensor checked.--------This will help.Thanks.Helpmech.

Marvin

• 85242 Answers
• Posted on May 25, 2012

SOURCE: My 98 gmc 1500 V8 5.0l won't start. Has good spark

Spray starting fluid into the air intake of the engine, if it starts and you have fuel pressure you have no injection or injector pulse as we call it. Check ECM fuse one and two for continuity if it starts with fluid..