'87 S10 Starting Woes

[nascar48fan]

I have a 1987 Chevy S10 Ext. 4WD with the 2.8L 6 cyl. eng. Whenever the truck has been sitting for more then 3 to 4 hours, it is borderline impossible to start. It cranks over and over and over...and after maybe 15 minutes of this (or until the battery is dead) it starts to sputter, and then eventually after a few more attempts it will fire. During this whole ordeal, you'll get a strong smell of fuel. The guy I purchased the truck from said it was the throttle position sensor but a friend of mine said it may be a clogged or dying fuel pump / filter. Any help on this would be greatly appreciated. Thanks in advance.

UPDATE: After fighting with the ALDL and a paperclip like the "Accessing Trouble Codes" forum says, I saw the check engine light flash 12, or so I think. I looked at the codes and didn't see a code 12 for my engine class, so I'm assuming I read it wrong and it's actually a code 21: Throttle Position Sensor TPS or circuit voltage high. Now does this mean the TP sensor has to be replaced or what? I'm stuck now...

Please help...

[1stGenFan]

Code 12 always shows (diagnostic mode). It'll blink code 12 three times, then any other code(s) will follow the 12. Is the check engine light on?

Sounds like no or weak spark. Did you change cap/rotor/plugs/wires?

Is it TBI or carb? If carb, maybe the choke stuck closed causing flooding.

[nascar48fan]

I let the check engine light flash three times (was unaware of that) and it flashed a code 15: Coolant temperature sensor or circuit/ low temperature indicated.

It has a carb, but does not appear to be stuck open. I have not replaced the wires, plugs, etc as of yet but they're all in pretty tough shape.

Could it be just a combination of all of these things that are making the truck hard to start? I started it up today and it fired faster then normal, but still with great difficulty. Once I got it to catch, she sputtered and sputtered and stalled. Once it started to warm up, it would stay running but once I reved it up, it sputtered again wanting to stall. My gas gauge is faulty as well so i could just be out of gas.

[cyclonetwister]

It'll flash codes in a series of 3....i.e. 12-12-12 followed by (in your case) 15-15-15, (whatever other codes you have stored)- (whatever other codes you have stored)- (whatever other codes you have stored)- followed again by the 12-12-12 meaning that it's reported all of the stored codes.

If you want to clear the codes just disconnect the battery terminals for 5 minutes then reconnect..

As for the starting problem, I'd check for gas first, spark second...

Originally Posted by nascar48fan

I let the check engine light flash three times (was unaware of that) and it flashed a code 15: Coolant temperature sensor or circuit/ low temperature indicated.

It has a carb, but does not appear to be stuck open. I have not replaced the wires, plugs, etc as of yet but they're all in pretty tough shape.

Could it be just a combination of all of these things that are making the truck hard to start? I started it up today and it fired faster then normal, but still with great difficulty. Once I got it to catch, she sputtered and sputtered and stalled. Once it started to warm up, it would stay running but once I reved it up, it sputtered again wanting to stall. My gas gauge is faulty as well so i could just be out of gas.

[longhairedg79]

I had a simular prb and it turned out to be the needle seat in the carb. I would say try the gas, then tune up first though, and spary a little carb cleaner in the carb. but that is just me