1986 s10 2.8l


#1

I’ve got a 1986 S10 pickup with a 2.8L engine. Every once in a while, when I go to start it, it cranks but will not start. I am careful to not step on the accelerator when I go to start it, since it has a throttle body fuel injection system. After several tries, I will try stepping on the accelerator as recommended in the manual, but to no avail. It has happened 7 or 8 times in the last 3 or 4 months. But it is getting worse in the last couple of days. It finally starts after 15 or 20 tries in about 15 or 20 minutes. Once it starts, there is no problem. Any ideas?


#2

When was the last tune-up?


#3

I bought it about 6 months ago, and had a mechanic look it over. I asked him to give it a tune-up if he thought it was ready for one, and he thought it was fine. I also took it to him when the problem first occured, and his only thought was maybe the fuel pump. But that didn’t seem to make sense, as there is no problem once it starts. Short answer is, I don’t know when it was last tuned.


#4

Determine whether the problem is fuel or spark or both. My first guess would be the fuel pump relay. I believe there is a redundant fuel pump circuit in the oil pressure sender but an old engine may not quickly build the required pressure to activate it… While listening at the fuel fill spout have someone turn the ignition on. The pump should be heard for a few seconds, then turn off until the starter is engaged.


#5

Especially with cars this old, when I acquire them I change all the fluids and do a full tune-up, replacing all filters. This helps eliminate odd problems like this from possible neglect. Rear differential and transmission fluids are the most neglected. For a truck like this, I can usually do this for around $150 in parts.

Do a full tune-up, including plugs, wires, cap and rotor. And, check the timing, and replace fuel and air filter. Then please post back, and see if that makes the difference. Spark plugs typically last 12,000 miles/1 year for this truck (copper core), and you’ve put 6 months on spark plugs of unknown age. I always replace cap and rotor with the plugs, but check the wires, and typically replace those every other time. Also, the filters are of unknown age, and it’s just good to start the clock fresh on those.


#6

Very good advice, guys. I’ll go ahead and give it a full tune up and look into the issue with the fuel pump relay. I’ll let you know the results. Thanks.


#7

I thought that my best route was to try replacing the fuel pump relay switch first before anything else. And sure enough, it started right up!! It wouldn’t start at all before I installed the new switch, so I’m convinced that was the culprit. Thank you so very much for your helpful advice.