88 suburban starting problems

You have an issue (or issues) with fuel delivery, fuel flow, (and or) fuel volume. Post the results of a fuel pressure test, and a fuel leak down test.

Ok. i will do that tomarrow. the fuel pump is new. but the old one did it to.

Ibeme,

OK in your original posting if you had posted that the fuel pump is new, and that you had this problem with the old pump, I would have recommended different tests for you to do. For now you can disregard the tests I mentioned in my first response. Now we need to know:

Engine size
What series suburban (R or V)
2 or 4 wheel drive
TBI or something else (via conversion)

Ibeme,

I would like to get more vehicle info but I think Big Blocks tests are appropriate regardless.

Since most Suburbans (by far) are gas and not diesel I am going to assume you have a gas engine. Please correct me if I'm wrong.

This link may help you with the tests:

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f80c90ec8

Also listen for the pump to energize for about two seconds when the key is first turned to the run position (best done with a partner turning the key).

Post back here and let us know what you find. Thanks.

Hello Ibeme,

This doesn't necessarily have to be a TBI. Let's begin by confirming that fact. Tell us the type of fuel injection system is in your truck. If necessary get the help of a professional who can confirm the type of system it is and then post it. I also agree, that Big Blocks tests should not be ignored, but I can see where he's going with this. He wants you to understand that the tests cannot be done if the fuel pump is not even coming on in the first place.

Thank You
Helene

Ibeme,

Something Helene posted made me want to go back and read your original post.

I want to be clear on what you meant by "wont start unless i use starting fuid". Does it start with the use of fluid and then continue to run on its own or do you have to keep spraying for it to run?

Please explain your problem in detail. This info can be quite helpful. Thanks.

Iberne,

Your latest posting brings you back to my original tests, but this time with a twist. That twist is to eliminate the Fuel Leak Down Test. Had you told us what you are telling now, in your original posting you could have saved alot of time, and most likely had the truck running already. For future reference give us all the details in your first posting. Remember, this is online auto repair and we don't have your truck in front of us, so we gotta ask questions and you gotta give us answers.

OK so here's what you gotta do now. The reason it only starts with starting fluid is because you are losing Static and Residual fuel line pressure. Replace the fuel filter if it hasn't been replaced recently. If replacing the fuel filter doesn't help, and the condition still remains, then replace the fuel pump as the Check Valve built into the pump has failed.

Iberne,

With all due respect to my skilled colleague I would recommend a little different approach. I feel that it is a fuel pressure problem but I would recommend that you check other items prior to replacing the pump.

As I stated before you should have a brief power signal to the pump when you first turn the key. This is designed to pressurize the system prior to start up to help make up for any pressure that might have been lost while the vehicle was sitting. If you can't hear the pump energize and turn back off this is a problem and usually a simple one.

There are still other possible problems outside of this but let's take this one step at a time to try and avoid confusion. You have already replaced the pump. You could have gotten a bad pump but don't replace it again just because the truck still has the same problem. As far as the replacement of the filter I would say SURE why not if it hasn't been replaced with the pump but outside of that it's time to test not guess.

Post back with the results and we'll go from there.