Hello all. I have a 94 jimmy 4.3 w. It does not want to start after sitting over night. It's gotten progressively worse. Sometimes it would take 3 or so tries and today I just gave up and took my other car to work after 20 or so tries and no obvious progress. After I get it started in the morning it will usually start up just fine every time for the rest of the day. Sometimes turning the key several times before trying helps. Pushing the pedal down while starting does not seem to help. I have seen many other posts on similar symptoms but most of the answers were that the spider/fpr needed to be replaced, which I already did. Replacing the injectors seemed to help for a little while but that was during the summer. Now it is back to not wanting to start. Sometimes it sounds like it really wants to start and is almost there, but today it didn't really seem to be trying. When it does start, it seems to be a slow jumpy start like it is working it's way up to proper idle speed on fumes almost. I've noticed the pumps on these trucks usually make a low humming noise but mine makes more of a static-like grumbly noise. I wasn't sure if this was relevant.
My question is, seeing as I already put in new injectors and I know there is no more leak in the plenum, is there something else it could be besides the fuel pump? I'd rather not go out and buy such an expensive part if I can try something else first. I have not checked the fuel pressure since replacing the spider and do not have the tools necessary to do so. I read some things about possibly the coolant temp sensor. Is changing this worth a try? Is there anything else that could cause these symptoms? Thanks!

 

The most important thing you can do right now before you start putting parts in it is, check the fuel pressure. That's what it sounds like to me, but there's no way of knowing unless you check it. you can buy a fuel pressure gauge cheaper than you can buy just about any part you may try and it not be the problem. And you can't really be certain the injectors are not leaking without checking the pressure.

 

The injectors are brand new. I know they are not leaking. I had the spider put in by my dads best friend who is the best mechanic I know. I know I can rule that out but thanks for the suggestion. I even looked in the plenum just recently to verify that there is no fuel pooling in there. Everything is dry and there is not a strong gas smell at all.

 

That would really be great if it meant anything, but it doesn't mean a thing.

I installed one a couple of months ago. The injector was bad in it. Rather than take the whole thing out and take it back I just took the injector out of my old one and installed it in the new one.

And you don't really know that it's letting fuel through to your injectors. That's what mine was doing, the main injector was not opening.

 

I changed the fuel pump. It starts up and runs great! Thanks for the suggestions. My only issue is that with the old pump the gas gauge read 3/4 with a full tank, and now with the new one this problem persists. Could there be a problem with the gauge? I'd like everything to work properly. The unit I installed is a brand new delphi and runs amazingly. Any ideas why the gauge could be off?

 

Anyone? Please? I don't want to start a whole new thread for something that has to do with my last issue anyway. The only isssues with the fuel gauges I've read about has to do with the sending unit but I really think this is something else since it was like that before the new pump and still the same after.

 

I've just dealt with the fuel gauge on my '93 LeSabre and I can offer a little bit of advice: find the testing procedure for the gauge and follow it. For my LeSabre that meant getting under the car, disconnecting the fuel pump wires and checking resistance on the circuit going to the gauge. It may mean something different for your rig.

To find the proper testing procedure check out All Data or Mitchell's. I can access Mitchell's through my local library for free. You may be able to do the same. You may also want to find a copy of the factory shop manual on eBay. I find them to be valuable resources.

 

If you remove the fuel gauge wire and ground it, it should go to full. Remove it from the ground and it should go to empty. That's a quick way to tell if your gauge is working right without a lot of other testing. The gauge works off resistance. Did you just change the pump or the sender too? Clean the ground. It's on the rear crosssmember above the rear bumper.