99 Safari started cutting out... Ideas?

SoCalChris · May 22, 2006

We've got a 99 GMC Safari, RWD. Yesterday morning, we were heading into town, and after about 30 minutes of driving, the engine started cutting out real bad. It felt almost like I had water in the tank, so I put a can of water remover in the tank, and then topped the tank off with gas from a different dealer.

After I towed it home, I let it idle for about an hour, which it did without any problems.

Last night, I tried driving it to the store, which is about 3 miles from us. It got down there without any problems, but on the way back, it only made it about 1/4 mile before it died. I ended up having to tow it home again.

Any ideas what the problem could be? It seems fuel related to me. Is the filter easy to get to on this model, or is it in the tank? Prior to yesterday morning, there was no indication that there was anything wrong, it was running like a champ.

Thanks

Hecktorx · May 22, 2006

I just had a similar problem on my 03 Silverado. It turned out to be I had about a 1/2" of dirt in the bottom of my tank. It would start up and run fine, but after a while, the pump would start sucking up the dirt in the tank and block the strainer in the tank.

ChevyTech007 · May 23, 2006

What size engine do you have?

SoCalChris · May 23, 2006

4.3 V6, with 91,000 miles on it.

ChevyTech007 · May 23, 2006

First thing I would do is put a dist cap and rotor and coil wire on it. Fairly common problem. Check you fuel pressure and check for fuel in the vacuum line to the fuel pressure regulator.

MustGoFaster · May 23, 2006

do the 4.3's still have the TPI? some of the earlier ones had tons of problems with that unit. if the newer units still have it, then I'd start your troubleshooting there.

SoCalChris · May 23, 2006

Thanks a lot ChevyTech007, that makes a lot of sense. That would probably explain why the van let me drive it to the store, then died on the way back (After then engine had warmed up). I'll check those out tonight.

MustGoFaster, what's a TPI?

MustGoFaster · May 26, 2006

TPI (may not have the designation correct) was a fnuky central injector system GM used on several of the 4.3's the design incorporated some bad seals, and was generally regarded as a pain in the arse, in adddition to being expensive to fix.

However, I beleive it was used on earlier 4.3's and has been phased out in the new models.

MustGoFaster · May 26, 2006

did some digging around. the injector is called a CPI unit. those were the bad ones.

SoCalChris · May 28, 2006

I tried ChevyTech's suggestions, and unfortunately none of them worked. The distributor cap was looking pretty worn though, so replacing it was probably a good thing.

I wound up towing it in to the dealer (It gave me a good excuse to get a hitch for my truck ), where they replaced the crankshaft position sensor. Total parts & labor came out to slightly less than the warranty deductable, so it worked out good, and the van is running good again.