96 blazer stalls when hot

[mcdon26]

ok guys, any objections to this? http://cgi.ebay.com/ebaymotors/Delph...#ht_4400wt_939

[maxisp2000]

It's cheaper on Amazon.

http://www.amazon.com/Delphi-FJ10565...ar=1&carId=001

I am almost to that point too. Just a couple of more tests.

[MT-2500]

Originally Posted by mcdon26

ok guys, any objections to this? http://cgi.ebay.com/ebaymotors/Delph...#ht_4400wt_939

If it is Delphi it has got to be good.
But that does not fix the fuel pump.
MAKE SURE WIRING AND GROUNDS AND POWER FEED TO IT ARE GOOD AND GO WITH A DELPHI oem PUMP SETUP TO.

[mcdon26]

alright, hold the press, I was about to pull the trigger on the set from Amazon when I went out for another look at the motor. MT, my fuel lines go into the top of the intake, not the back as I previously thought. I hate to get into this thing and have the wrong parts. I don't want to be out 200.00 bucks.

Maxis - any word on what heat sink you used and where you mounted it. You have any pictures?

[MT-2500]

Originally Posted by mcdon26

alright, hold the press, I was about to pull the trigger on the set from Amazon when I went out for another look at the motor. MT, my fuel lines go into the top of the intake, not the back as I previously thought. I hate to get into this thing and have the wrong parts. I don't want to be out 200.00 bucks.

Maxis - any word on what heat sink you used and where you mounted it. You have any pictures?

No nut kit in there than.
The picture on Amazon is the right one for the line in top setup.
But I would just check/replace the fuel pressure regulator.
And check out /replace fuel pump.
A good delphi pump unit will hurt way over 200$

[mcdon26]

Originally Posted by MT-2500

No nut kit in there than.
The picture on Amazon is the right one for the line in top setup.
But I would just check/replace the fuel pressure regulator.
And check out /replace fuel pump.
A good delphi pump unit will hurt way over 200$

thanks, yes I plan on replacing both the fuel pump and the spider assembly at the same time, or I should say same weekend. Good thing about the new spider assembly that was listed on amazon is that it includes the fuel pressure regulator

[maxisp2000]

Ok here I am. Sorry for the wrong part, I thought your intake was different. I don't have a nut kit either. Lines go into the top of the injector.

Today's test. Drive 45 minutes, stop 3 times. Go on freeway 30 miles. Start fuel pressure test.
58 start up, on demand, pressure rises to to 65. Falls to 58 at idle.

Turn off engine.
Pressure drops to 55 in seconds. No further drop in pressure. One hour later pressure at 50 engine cold.

I don't think there is a spider problem, or them leaking hot.

McD, did you press the pressure relief before your tests? Because you may have been leaking down an air slug at the top of the valve.

Drive 3 miles around the Las Vegas Speedway area. Gas pressure never varies from previous settings. A little needle bounce from speed bumps.
The scan tool shows no problems.

Removed pressure tester drove 65 miles around beltway.
Car ran fine.

I wrote a detailed explanation of the heat sink and the site returned an error when I saved it.

[maxisp2000]

ICM heat sink

I got an old scrap heat sink from something. I trimmed it to the same size as the original. Using the original holes as a template I drilled matching holes in the scrap heat sink. Using new long bolts and nuts I assembled ICM/silver paste/stock heat sink facing out/silver paste/scrap heat sink facing out the other way/U bracket.

Using a piece of aluminum sheet, I made a "serif" U bracket that matched the coil mount bracket and mounted the assembly on the old bracket. The silver paste is used to thermally connect a CPU or chip to a heat sink.

Reconnect.

Car has not failed since.

[mcdon26]

Originally Posted by maxisp2000

ICM heat sink

I got an old scrap heat sink from something. I trimmed it to the same size as the original. Using the original holes as a template I drilled matching holes in the scrap heat sink. Using new long bolts and nuts I assembled ICM/silver paste/stock heat sink facing out/silver paste/scrap heat sink facing out the other way/U bracket.

Using a piece of aluminum sheet, I made a "serif" U bracket that matched the coil mount bracket and mounted the assembly on the old bracket. The silver paste is used to thermally connect a CPU or chip to a heat sink.

Reconnect.

Car has not failed since.

Got a failure today. I have a video I am uploading so everyone can see what my experience is. According to the truck outdoor temp sensor it got to 94 today. I had no issues driving home at all. Once I got home, I turned the key off and pressure dropped to 42ish as it always has. When I turned the key back on, I got no movement in pressure what so ever. repeated several times with no movement. and the truck would not start. I decided to hit the pressure relief valve on the pressure gauge to see if I was potentially clogged or vapor locked. I relieved all the pressure and turned the key on. I could here the fuel pump had kicked on, I was hearing it from under the left side of the dashboard. Pressure increased some, but as the fuel pump ran to build pressure as it should, but it only jiggled in placed with no great increase in pressure. Once the videos upload, I will post links so you can see what i'm talking about. Peace

[mcdon26]

video 1 failed fuel pump

video 2 no fuel pressure

sorry for the scratchy videos.

All signs pointing to Fuel pump alone???

[mcdon26]

went out to the truck an hour after it sat and turned the key on, fuel pressure went back to normal and truck start on third crank

[MT-2500]

Originally Posted by mcdon26

video 1 failed fuel pump

video 2 no fuel pressure

sorry for the scratchy videos.

All signs pointing to Fuel pump alone???

yes and no.
May be not all but most or no 1 problem .

No fuel pressure points to fuel pump fail but you need to confirm good power and ground to it when it has no pressure.

About 5 lbs Low regulater fuel pressure may be bad fuel presure regulator.

I would replace pump with a delphi unit.
Do not use a Airtex or aftermarket unless you want to be replacing it 4-5 times.
And check wiring to it.
Then retest running fuel pressure.

Good luck and let us know how it goes.

[maxisp2000]

Good job, it looks like a bad fuel pump.

Just check the relay and grounds too.

I hate changing GM fuel pumps. My Camry has a access panel underneath the rear bench and changing th fuel pump is a snap.

[mcdon26]

thinking a little more on this last night, I was wondering, if the fuel pump is in the tank which we know to be true, what am I hearing up under the dash when the key is turned on. I know it is directly related to the fuel pump because when it kicks on I hear it and the fuel pressure increases, when it goes off the fuel pressure decreases. I only hear it when the keys is turned on for a few seconds without starting the motor.

I'm still a little hung up on why this only occurs when the temp is above 80

[MT-2500]

Originally Posted by mcdon26

thinking a little more on this last night, I was wondering, if the fuel pump is in the tank which we know to be true, what am I hearing up under the dash when the key is turned on. I know it is directly related to the fuel pump because when it kicks on I hear it and the fuel pressure increases, when it goes off the fuel pressure decreases. I only hear it when the keys is turned on for a few seconds without starting the motor.

I'm still a little hung up on why this only occurs when the temp is above 80

Key on the computer turns the fuel pump relay turns the fuel pump on for a 2 second prime up.
Engine cranking or running the engine computer turns on fuel pump relay.

That is why you should check for 12 volts to fuel pump key on 2 second prime up or engine crankig or running.

If the fuel pump relay fails to turn on fuel pump you will not have fuel pressure or pump running.
If on engine cranking you lose spark on secandary ign the computer will not turn on pump relay.