92 hard to start when hot

[Jerry80871852]

Here sometime back I had trouble out of my EGR Valve. 1st time it got to where it was had to start.

The EGR was stuck, so I cleaned it and put it back on, worked for a while, finally I had to replace it.

Now I'm once again having trouble, thought at 1st that maybe it had stuck open again, but it wasn't.

When cold it starts great, but when its hot it will not. I've noticed if I will hold the throttle wide open before trying to start it when its hot it will start, but runs rough for a few minutes.

But if you don't hold the throttle open, it will just crank and crank not even trying to start.

Any ideas would be appreciated.

Oh, its had 2 fuel pumps put on it.

[blazes9395]

Sounds like its flooding. Holding the pedal to the floor puts the truck's PCM/ECM into flood clear mode, and stops the injector from firing and throwing gas in the engine. With it running rough after it starts, it sounds like its just buring the extra fuel. When its cold it needs the richer mixture, plus it sits for awhile so some gas evaporates and it starts without problem.

I would pull the upper intake and look for leaks. With key on engine off, let it prime and see whats there. If you see no leaks at this point, fire the injector manually by jumpering the injector from the battery, and see if you have leaks at the nozzles, and/or the little tubes.
Good Luck!

[Chris Stewart]

I agree with Blazes,
After removing the top, it's supposed to be grungy inside. Any bright, clean areas are where fuel is leaking or spraying. Clean passenger side area is a fuel regulator problem. Clean drivers side area is a supply or return fuel supply problem.
Here's some pressure regulator replacement pics.
http://www.automotiveforums.com/vbul...=cpi+regulator

[Jerry80871852]

I thank both of you for your replies. I meant to get back sooner then this got thank you for the information.

In the old days I did quite a bit of work on Chevy's, back when they had points and Rochester Quadrajet Carburetors. But the modern day computer and fuel injected engines are foreign to me.

But I have seen the inside workings, had to replace the gas line to the spider about 30,000 to 40,000 miles back. At that time I did have a friend who run codes on it 1st, but there were none, he suggested what y'all have, take the cover off and check the lines and such.

I did go look at your fuel regulator replacement pictures.

Yesterday I talked to a person, who gave me basically the same information as you 2 have, but he did say, I would run codes before talking off the cover and checking the spider.

Last night I was going to call my friend and ask him if he could run code on it this weekend, but he has since divorced and has no telephone and now works out of town, so that may not work out.

I might add, when 1st started it idles fairly well. But after I drive it to town the idle is a bit rough. And as I previously said, if you kill it and come back in a short time the only way it will start is to hold the accelerator to the floor. When it starts you can smell much gas from the exhaust.

The for a few seconds you have to hold it above idle or it will die, especially if you put it in gear.

My gut feeling was that it is the spider.

I did order a top gasket set yesterday, for here in rural Arkansas usually its not in stock and has to be ordered.

From what I gather yesterday talking to my parts man, the spider and fuel pressure regulator comes as one unit, the price was a bit over $350.00. I had been told a few years back that they were around $550.00 to $600.00.

Out of curiosity, do you know how many years models used this spider set up like the 92 S 10 Blazer?

[blazes9395]

The spider unit used in these trucks was used from approximatley '92 to '95. They were used in the s-10's, astro/safari vans, and of course blazer/jimmy's that had the W engine code.

For sure get it scanned, you have to see whats going on there. From there take a look at the spider unit, if all that checks out it could be a 02 sensor, or even the ECM itslfe that starting to go out.

Good Luck!

[MT-2500]

Double check all basics.
For checking codes.
http://www.troublecodes.net/GM/
If you get any codes post back code no.
A fuel pressure check and test will help pinpoint a leak in the injector system.
Watch for a fast leak off on fuel pressure.
If it is leaking in there when you get the cover off prime up fuel pressure and look for the leak.
They can leak at the fuel pressure regulator or the plastic fuel feed and return lines called a fuel line nut kit.
MT

[Jerry80871852]

Right on the fuel nut kit, replaced it a few miles back, the one coming in was split and spraying gas everywhere.

Went to my friends house, had his old computer at home. Guess what, it pointed to the spider.

Did not have his fuel gage at home, it was 30 miles away where he works. His old computer doesn't show fuel pressure.

Probably early next week I will put the cover. He told me if I did not see a leak to call him at the shop and he would bring some equipment and come out here to check it further.

Thanks again for the help. When I find more out I will post it, maybe it might help someone.

[Jerry80871852]

I pulled the top intake yesterday. It was leaking real bad from around the regulator.

Which I had started it and moved it to another location, as soon and I took the breather loose I could smell gas fumes real strong. If someone has a similar problem in the future, if they will unhook the flexible rubber tube on the intake they can probably smell the excess gas that's under the intake. The fumes from mine would nearly knock up down.

I'm going to replace the injector, having more than 146,000 mile on it and planning on keeping it for a few more years, I feel that is the smart thing to do while I've got it opened up.

I'm going to go ahead and replace the fuel lines, I believe y'all have said GM calls it a nut kit, that hooks to the injector, I believe that when my friend replaced the incoming line, it split about 50,000 miles back, that he only replace the fuel incoming line, not the return line, seems silly to me not to replace both of them while I've got it opened up.

I bought it new in 92, I'm still not ready to get rid of it, its been a very good ride, drives and rides like new and I feel it drives better than our 2002 Jeep Grand Cherokee.

About the only thing rightly wrong with it is in the last 3 to 4 years the white paint has been turning loose, which I suppose I'm fortunate, for I know many of the white ones did this in the 1st few years they were on the road.

When my friend had the computer on it, at 1st the temperature was running at about half of what it should. After a bit it jumped back up running normal. So while I have the top intake off I'm going to go ahead and change the sending unit located on the front left hand side of the motor kind of below the EGR valve. Be much easier to change it while I have the top intake off. I understand this sending unit goes only to the computer.

I went to the code page posted, I sure didn't know you could take a paper clip and or a jumper wire and read codes on at 92 S-10 Blazer. I appreciate that info, thanks for posting it.

Here is the code page again.

http://www.troublecodes.net/GM/

But I don't see no code listing for my 92 4.3 Multi Port Fuel Injection with a W motor. Am I missing something something?

[MT-2500]

Is yours a S-10 or a S-10 blazer. One or a S-10 does not list a W engine until 93.
A L35 engine.
But no problem.
Just use the 93 W engine codes.

[Jerry80871852]

And I thought I had Blazer in my signature, but I didn't. But its there now for I went and added it right quick.

Don't remember where I saw it, but the other day I was doing some searching and I read something that said the 92 S-10 Blazer's 4 X 4, the biggest majority had the throttle barrel system.

From what I here it doesn't get as good of fuel mileage and doesn't have as much power as the multi-port fuel injected engines.

So mine is the same as a L 35 engine in a 93 model.

I'll see what it does when I get it put back together, my parts are suppose to be here sometime after dinner tomorrow.

I was surprised me, in less than 45 minutes I had the injector out.

[Jerry80871852]

Parts came in today, they are installed and my old Blazer runs better than it has in quite some time, nearly like a new one.

Injector kit and nut kit were from Delco. They came out of Memphis, TN, ordered yesterday morning, got here about 11:00 AM this morning.

Injector kit 393.93
Nut kit 75.16
Temperature sending unit 17.59
Gasket 9.64
shipping charge 9.50
taxes 46.66

Total $552.84

The worse part of it was getting the fuel lines coming into the back side of the intake started. Thought I would never get them. I finally slid them things out the back side of the intake, got them started, them slid them back in and them all went well.

If I were to do it again and or telling someone the best way to do it, I would get them started before sliding them in the backside of the intake. I would have saved probably more than 45 minutes if I had known that.

Thanks much for the help, appreciate it so much. Especially the pictures that were posted, that in itself is worth so much when tearing into something like this.

[MT-2500]

You are welcome and.
Thanks for posting the fix and how it went.
Glad all is well now.
MT

[Jerry80871852]

Do you have trouble with those fuel lines coming in the back side of the intake?

I did not mention it, but I did grease them down right good as well as the hole they go into hoping to prevent cutting or nicking the O-rings.

I learned to do that when I was a jet engine mechanic in the Air Force back in the last half of 1965. I found that would prevent many headaches caused from tearing things down a 2nd time and putting them back together again. The 2nd time was never as enjoyable as the 1st time.

[Jerry80871852]

This is much like the trouble that I'm having with my 92 S-10 Blazer is doing.

Not that many miles back I replaced the injection spider, The story is right here, everything worked great for a while, now at times when I start it, I have to use starting fluid, although at times it starts OK. After it has been started I drive to town it starts just fine.

Yet last week another problem showed its face. It started idling to high. I checked to see that the accelerator was not sticking inside or under the hood, and it wasn't. So I started unhooking sensors one at a time, the 1st one was the one across for the throttle valve. Just a few short seconds it idled back to normal.

I went and talked with my favorite parts man, he suggested taking the sensor off and clearing it up as necessary before buying parts. I had not idea what the sensors looked like on the other side. So I took the one on the throttle off 1st, there was nothing to clean on it. Them I took the one off on the accelerator side. It was a bit dirty and I cleared it up. The other 2 it did not seem there was anything I could do for them.

After doing this it started fine, and idled properly, so I leave it to try today and see what happened. Same thing, had to use starting fluid to get it started, after it started it idled to high, I unhook the sensor across for the accelerator and it idles just fine. Seems to run a OK.

Could these 2 problems be connected? Thought I would ask before I went any further.

Since this topic was so much like mine, I thought I would 1st post it here, them go from there.

[old_master]

Using starting fluid is dangerous and can damage the engine, best to use carb spray instead.

If it starts when doing this, it's a classic symptom of low fuel pressure or excessive leakdown, or both. Ignition ON, engine OFF, fuel pump running, fuel pressure must be 55psi to 61psi and must remain above 50psi for 3 to 5 minutes after the pump shuts off. Post your results.