Question for any of the Vortec rigs

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So I changed the fuel pump today to an Airtex E2000 and installed a Wix fuel filter and now the truck is taunting me!! It won't start, only pretend to fire and then quit. I'm going backwards now, this morning it ran with the old fuel pump and now it doesn't with the new one! I hear it priming itself when I hit the ignition but I guess the pressure is too low but these pumps are supposed to be rated at 65psi. Maybe this pump is no good. I need to go buy a fuel pressure gauge.....
 
Yeah.. fuel pressue gauge is your friend. I don't want to add another variable in the mix but potentially you might have a fuel pressure regulator issue (its part of the so called fuel spyder) on the 5.7 vortec. I upgraded to the "new and improved" sypder on my truck some time ago.

You've got to verifty fuel pressure... I think if you look in the shop manual it will note some steps to take..in diagnosing the fuel injection. One is to take a reading with just key on...and let it sit a while to see if the pressure drops...the other important reading is to take with truck running...but right now that's not an option for you.
 
I think some of the people don't care for the airtex fuel pump?? I think Rover67 had one on his truck one time...maybe he will comment on this thread...even though he runs a 5.3.

I did have a MAP sensor fail one time wihout setting a code (it got out of range) and made the truck run like crap....very rich... I would focus for now on your fuel pump/ filter and potentailly the regulator right now, because it makes no sense that your truck would not start? I do know that there are many different fuel pumps and GM is not kidding aroudn when they say that you need a certain min pressure for the system to run....I've seen it be an issue many times...
 
i use the airtex pumps as well and they've been very reliable. the engine should start with as little as 20psi ( but it won't run right ). make sure you cycle the ignition a few times to get all the air out of the system before trying to start the truck.

did you try it in third gear?
 
Another question as I dive into the pump issue this evening. Does the filter placement make a difference. Between the tank and pump? Between the pump and the engine? If it's between the pump and engine, do I run a screen of some sort between the tank and the pump? As close to the tank as possible? Filter nearer the engine? Any other variable I'm missing?

I ordered a Walbro GSL392 today. Seems that is the preferred animal. I'm going to swap in my old pump tonight to see if I can solve the no-start issue so that I can tackle some other work while I'm waiting a few days for the Walbro to arrive.

This is my first venture into the world of injected conversions. I've always done carb stuff before and never had to worry so much about fuel pressure/ volume.
 
Evening update. Swapped my old pump back in and she fired up right away! I guess the new E2000 isn't up to the task or maybe this one is just a dud. In any case, I'm taking it back to O'Reilly's tomorrow for a refund. I'm sure they will fight me on it but if they insist on only exchanging it, I'll upgrade it to the E8248 to keep as a spare. When the Walbro pump comes in later this week, I'll install that one.

BTW, the old pump is an E8248.

Still looking for input on filter placement. Before or after the pump?

Once this is all sorted out, I'll get back to the original issue, the hesitation at freeway speeds.
 
Simon, I'm running a big-assed aftermarket filter between the pump and tank. I think my pump has some cavitation, but it works fine since I figured out my loose weatherpak terminal problem. No hiccups at all, now. I'm thinking about changing my filter scheme to a large-chunk/no resistance screen before the pump and small-chunk high pressure filter after the pump. Maybe I'll try the filter that was made to work on the truck that the engine is designed for. We'll see.

On another note, please send me an email address. I was at my GMC parts department talking to a friend of mine and scratching my head on another project I'm working on. While there, I had my buddy print out the GM system check guide for the 5.7 Vortec fuel system. I scanned it into a PDF and thought it might give you some general ideas regarding what to check for your problem.
 
Here is my setup on the fuel filter pump business...

About 2 to 3 feet of new rubber fuel hose runs from fuel tank outlet port to a inline "russel brand fuel filter..I think there are pics of this somewhere...that then feeds the above referenced walbro fuel pump which is mounted on the frame rail fairl close to the right rear tire...there where the frame is straight..then it immediatly feed the GM OEM / SUV/Pickup fuel filter...after which braided fuel hose maybe 3 to 4 feet long runs from the filter which is also mounted to the frame up to the back of the engine where it mates with the fuel rail of the engine. Both fuel filters, and pump are all withing the same general area..and then a long run of fuel line up to the rear of the engine.

I use the GM fuel filter....for a couple of reasons..one (its a proven solution) two, ( its easy to swap out and easy to find).

I can't find a pic on my computer ( I thought I took a picture or two of the setup back when we istalled it) If I come across it I will edit this post and add picture..
 
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Elbert, do you have a part number for that GM filter? That was what I forgot to get from my parts guy today...

Thanks.
 
I don't have the part number but just ask for a fuel filter for a 1997 GM pickup with 5.7 engine... I think its teh same fuel filter for 96-99 and maybe even other year models.. GM SUV or pickup with 5.7 Vortec engine.

http://www.rockauto.com/catalog/x,carcode,1353350,parttype,6200


I'm pretty sure this is the one GF652 Fuel filter... Link above is from Rock Auto... 99 truck with 5.7.

http://www.rockauto.com/catalog/x,carcode,1052705,parttype,6200

see this link for 97 year model..same filter..GF652
 
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i have my fuel line set up with a pre pump filter and a post pump filter. for what ever the reason this was recommended to me by the guys at the local speed shop. the pre pump filter has to do with the 1984 gas tank and the chance for rust flaking off.

i have rubber gas line from the tank and @ the 1 foot mark i have the large micron pre filter. the fuel pump sits before the wheel arch. the walbro pump is gravity fed so it is at the lowest point in my fuel line. i have the conventional inline fuel filter at the front just before the fuel line turns upward into the engine bay.

are fuel filters even needed? on most new passenger vehicles the filter is in the tank attached to the pump to catch the big stuff and no inline filters after that?

pre pump filter from summit racing is an earls #230206erl

inline filter from napa the gold oem replacement #3486

also i think my walbro pump is the best but i did run a delco # ep286 (gm# 25117086) and had good luck. it is now my back up pump.

devo
 
I would not run a fuel injection setup with just the "sock" type filter used on the in-tank pumps...I think you would just be asking for issues.
 
Installed the Walbro pump today, very quiet.

However, still the same original problem. Smooth idle, excellent power through the gears but as soon as it hits OD, there's a recurring misfire. It'll stumble and buck until I hammer the throttle and kick it down a gear. Then it will pull smoothly at high rpm until I let it drop into OD and the stumble reoccurs. No noticeable misfire at any other times. No codes coming up.

I've searched the web on this and come up with three fairly common problems.
#1. Distributor gear is worn.
#2. Pressure regulator/ fuel spider issue.
#3. Intake gasket leak.

Anyone have any other thoughts?
 
Devortex said:
Installed the Walbro pump today, very quiet.

However, still the same original problem. Smooth idle, excellent power through the gears but as soon as it hits OD, there's a recurring misfire. It'll stumble and buck until I hammer the throttle and kick it down a gear. Then it will pull smoothly at high rpm until I let it drop into OD and the stumble reoccurs. No noticeable misfire at any other times. No codes coming up.

I've searched the web on this and come up with three fairly common problems.
#1. Distributor gear is worn.
#2. Pressure regulator/ fuel spider issue.
#3. Intake gasket leak.

Anyone have any other thoughts?
Click to expand...

It sounds like it might be a trans related problem since it only acts up in OD?
 
Simon, one thing I can attest to is that the interwebz is full of $hit...

When I had my ignition problems, I, too, searched the internet and chased my tail solving everyone else's problems on my rig. I SHOULD have purchased a Helm manual for a 5.7 Vortec powered rig and methodically troubleshot it myself, but I didn't, and ended up spending over $1000 on stuff that didn't need replaced.

I really wish I had an idea what the problem is, but I don't. Before you spend money on parts, please find out how to test for those problems you suspect. It'll save you time, money, and headaches in the end.

The fact that your problem only occurs in overdrive is wierd. I'd try to figure out how the transmission interacts with the computer before I went any further. I don't know much, but those are my thoughts...

Good luck!

EDIT: Here's a link to the manual set I'm ordering to put on the shelf

http://www.helminc.com/helm/product2.asp?Make=GMC&Model=GCK+&Year=1998&Category=1&class%5F2=GMC&mk=GMC&yr=1998&md=C%2FK+Pickup%2FSuburban%2FJimmy&dt=Shop%2FService+Information&module=&from=result&Style=helm&Sku=GMT98CKF&itemtype=N
 
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jon makes a great point.

don't "throw" money at the problem without knowing what's wrong. do your research, something's gotta come up. it's a little perplexing that the problem only occurs in od. have you tried driving the cruiser at the same engine RPMs and load in third gear? does it feel like the converter is possibly going in and out of lockup? what happens if you try to drive it at 75 or 80mph?

the distributors on the first gen vortecs do wear out over time; they're not too expensive or difficult to replace. i just had to replace the injectors and dizzy on my 5.7 in the 80. not cheap and you'll burn the better part of a day doing it.

research, research and try to narrow down the problem as good as you can. the more info you have, the easier it'll be to diagnise the issue at hand.

hth

georg @ valley hybrids
 
for what it's worth. are you using the VSS with your set up?
Could it play a part in disrupting your timing in OD when the drive shaft is turning slower that the crank?

devo
 
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