88 burb igniton

[SucioD]

could a faulty ignition switch xause the vehicle to run poorly. i thought my starter, alt, and battery were giving me problems, but i think i may have traced it to the ignition switch. the starter just clicks, like it does not have enough power to crank. It syarted out sparatically, then got progresivily worse, and now it wont start and just clicks. i have also been having a problem with the engine sparatically bogging down under load. when i disconnect the timing wire by the firewall, it runs fine. i was wondering if these two senarios could be related. starter, alternator, coil, dist, MAP sensor, knock sensor, battery, and main comp. are all new. HELP!

[MT-2500]

Originally Posted by SucioD

could a faulty ignition switch xause the vehicle to run poorly. i thought my starter, alt, and battery were giving me problems, but i think i may have traced it to the ignition switch. the starter just clicks, like it does not have enough power to crank. It syarted out sparatically, then got progresivily worse, and now it wont start and just clicks. i have also been having a problem with the engine sparatically bogging down under load. when i disconnect the timing wire by the firewall, it runs fine. i was wondering if these two senarios could be related. starter, alternator, coil, dist, MAP sensor, knock sensor, battery, and main comp. are all new. HELP!

Bad switch could but not usually a bad switch.
You may have several problems.
If it runs better in base time mode.
Get the base time set with a timing light.
Go over basic tune up stuff plugs and wires and dist cap and rotor and fuel and air filter.
Confirm good fuel pressure.

On the electrical end get the battery and alternator and charging system checked good.
And do not forget the battery cabels.
Check and clean.

Check computer for codes and post back any codes.
Let us know how it goes.

[SucioD]

OK. I have completed all the testing I can dofrom checking and cleaning all grounds to replacing the ignition switch and nuetral safety switch. I still get low voltage in the starter when turning the key. I even ran 12v to the purple wire on the ignition switch, it turned the motor no prob! but when you use the key, i get the low voltage clicking starter CRAP! Had the battery tested and it turned out good except for it being a little low. Did voltage and load test. Starter, alternator, cables, ignition, nuetral safety switch, distibutor, cap, rotor, plugs, wires, ECM, MAP, Knock senor, and a bunch of other misc things are all new. Still runs better on base timing, NO IDEA WHY!!! I have traced or replaced almost everything I can think of and still have the same problem. The only codes I am getting are 42( probably due to the unplugged EST circuit) and 44 (lean Exhaust, maybe due to no cat, and no air pump, or fuel pump running at 10lb. I dunno!) ANY HELP WOULD BE MUCH APPRECIATED!! Thanx

[MT-2500]

Have you checked base timing with a timing light?

Code 42 is a electronic spark timing problem.
Open or a short to ground on est bypass circuit.

Is the only time it sets code is when the est is unplugged?

On low voltage to starter?
What is the key on start voltage to purple solenoid wire?

[SucioD]

Yes, the base timng was set with a timing light. And yes the only time it pops a code 42 is when the EST circuit is unplugged. As far as the other ?, I had the ignition switch off of the column when i was testing it. I believe the switch was in the off or lock position as i dont remember moving it to another position. i have since remounted it to the column and things seem to be OK. thought maybe it needed to be grounded to the column. Put a really good charge on the battery and away i went, no clicking so far. time will tell. As far as the other problem, I have a new distributor with new ignition module in it. When the EST circuit is plugged in it wants to bog down and run real rough and backfiring out the exhaust. ( I have blown up 2 flowmasters )The only thing i have not replaced is the EGR. This problem happens very sparatically. Sometimes i am able to turn the truck off and restart and it will go away. Sometimes it only happens when i put it in gear and other times it happens when it is in park. Done lots of testing, even had my mechanic friend put it on his computer, but the symptoms would not happen. Extermely frusterating!!! THANX for the quick reposts. Hope someone may have an answer. Thanx

[bigjimdaddy]

on the bogging down problem have you changed fuel filter i had a similar problem with my 88 sub turned out to be fuel fiter pluged up and fuel pump went out about a month later replaced both then it ran great.