1997 GMC Savana 1500, intake gaskets, EGR plumbing etc

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Peavey

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Hi again!

Just a little update. The intake is off and is now on the bench in the garage awaiting some further inspection. The hose connector seems to be fine and the leak I wrote about earlier seems to have been coming from the gaskets - leaking "upwards" towards the valve covers and on to the intake manifold. The gasket surface on the intake has also suffered from this as there is some pitting around the coolant passages. So, based on this, and some other stuff, I have a few more questions on how to adress certain issues. Hope that´s ok with you guys.

1. When I was removing the fuel lines, I noticed that there was some fuel underneath the cap which covers the shrader-valve (spelling?) on the fuel line. I suppose that means that the valve has seen its better days, but is this a "standard" valve like the ones usually fitted on for example tires or is it something more specific for fuel lines?

2. About the corrosion-pits on the gasket surface. Would it be possible to use "liquid-metal" such as JB Weld or similar to smoothen out the pits?

3. Before starting this intake-operation, I read a lot about the spider injection and how the poppet injectors eventually start to leak due to carbon build up, heat and whatnot. However, the updated mfi-units were (are) not available for order (at least on Rock Auto and Summit) aside from non-acdelco brands which does not seem to be a good choice given the reviews and opinions which came up. So, I thought, well, the van was running fine before so "why bother"....but....there is a scent of fuel coming from the intake, especially when opening the throttle, indicating that there may be a leak on the inside. After scouting the internet, I found a company in the US called Motor Man Fuel Injection who sells refurbished mfi-units with, according to their website, new ac delco injectors fitted along with new o-rings and other bits and pieces...I just wanted to ask if anyone here has any experience from this company or any other advice regarding the mfi-upgrade?

Thanks again and best regards!

//Johan
 

1998_K1500_Sub

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The updated mfi-units were (are) not available for order (at least on Rock Auto and Summit) aside from non-acdelco brands…
After scouting the internet, I found a company in the US called Motor Man Fuel Injection who sells refurbished mfi-units ... I just wanted to ask if anyone here has any experience from this company or any other advice regarding the mfi-upgrade?

No responses, eh?

I suggest you start a new thread with MPFI as the subject. Let’s see what people say. I’m curious.
 

1998_K1500_Sub

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You can do it but you need to tune out the EGR advance or else it won't run very well

JET’s “Dynamic Spectrum Tuner” can be purchased for around US$300. Installed on a laptop, and using the included interface to the ECU, one can “tune” the 1997 vehicle and, among many other things, disable the EGR.

If you want more details on this option, respond to this post or look around GMT400… this topic was covered by me and others earlier this year in the threads.
 

stutaeng

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Hi again!

Just a little update. The intake is off and is now on the bench in the garage awaiting some further inspection. The hose connector seems to be fine and the leak I wrote about earlier seems to have been coming from the gaskets - leaking "upwards" towards the valve covers and on to the intake manifold. The gasket surface on the intake has also suffered from this as there is some pitting around the coolant passages. So, based on this, and some other stuff, I have a few more questions on how to adress certain issues. Hope that´s ok with you guys.

1. When I was removing the fuel lines, I noticed that there was some fuel underneath the cap which covers the shrader-valve (spelling?) on the fuel line. I suppose that means that the valve has seen its better days, but is this a "standard" valve like the ones usually fitted on for example tires or is it something more specific for fuel lines?

2. About the corrosion-pits on the gasket surface. Would it be possible to use "liquid-metal" such as JB Weld or similar to smoothen out the pits?

3. Before starting this intake-operation, I read a lot about the spider injection and how the poppet injectors eventually start to leak due to carbon build up, heat and whatnot. However, the updated mfi-units were (are) not available for order (at least on Rock Auto and Summit) aside from non-acdelco brands which does not seem to be a good choice given the reviews and opinions which came up. So, I thought, well, the van was running fine before so "why bother"....but....there is a scent of fuel coming from the intake, especially when opening the throttle, indicating that there may be a leak on the inside. After scouting the internet, I found a company in the US called Motor Man Fuel Injection who sells refurbished mfi-units with, according to their website, new ac delco injectors fitted along with new o-rings and other bits and pieces...I just wanted to ask if anyone here has any experience from this company or any other advice regarding the mfi-upgrade?

Thanks again and best regards!

//Johan
1. I don't the answer.

2. Yes, that's what most guys do.

3. If your engine is running ok, just leave the spider be if you want. I used the BWD mpfi injector on my 5.7 a few years ago because one of the injectors was dead. Truck is not a daily driver, but so far so good. All of the units look practically identical, so who knows if there's even a difference between the brands?
 

L31MaxExpress

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1. I don't the answer.

2. Yes, that's what most guys do.

3. If your engine is running ok, just leave the spider be if you want. I used the BWD mpfi injector on my 5.7 a few years ago because one of the injectors was dead. Truck is not a daily driver, but so far so good. All of the units look practically identical, so who knows if there's even a difference between the brands?
When I managed an Oreilly store, I sold dozens of the Standard Ignition ones for 4.3s and V8s. Never had one returned for a problem. The thing looked identical to the Delphi sourced AC Delco one down to the plastic package it came in. Honestly between Delco, Delphi and Standard Ignition, get the cheapest one you can find, I believe its all the same.
 

Peavey

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Hi again!

First of all, thank you so much for all your replies and info, I really appreciate it.

As an update/respons: I have ordered a remanufactured spider unit from Motor Man Fuel Injection which should be arriving within a week or so. I do not know whether this was a good choice or if, based on your answers, I should have sticked with a new Standard unit...time will tell. I´ve had some mail correspondence with Motor Man and they seem genuine, flow matching the injectors etc so let´s just keep our fingers crossed.

As for the hose connector, it does seem like it is the factory fitting does not have any form of restrictor in it, at least as far as I can see.

I have also bought some liquid metal from my local parts store which is supposed to be able to handle 260 degrees C (don´t know what that is in Fahrenheit though, sorry). Hopefully, I will be able to use it as a "bondo" for the gasket surface.

Regarding the schrader valve, I don't know but I´ll keep an eye on it once it gets pressurised...we´ll see

As for the process...I have removed the upper intake, the spider etc and...boy am I glad I actually took it apart...it does seem like it has been leaking and the carbon build up on the inside was rather massive. Today, I have begun the tedious job of cleaning it all, bathing the whole thing in diesel and working it with brushes, a simple "bottle-brush" came in very handy btw working a treat in the ports on the intake, although my dear wife wasn´t that impressed when I used the kids´old bathing tub as a parts cleaning device B-)....anyway...we´ll see what happens...I´ll keep you posted and I´ll try to attach some pics of the van, and misc stuff down below....

Thanks again!

//Johan
 

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Peavey

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First of all, I realize that this update is beyond late, there are probably bottle posts moving way faster than me in this case. I have no excuse except from a really bad memory combined with a busy day-to-day life, but hey, who doesn’t have that? All in all, I apologise for not responding back sooner.

To summarize: I got van back together with new intake gaskets, spider injection etc. I actually ended up buying a second mpfi spider unit (Standard Motor Products) from Rockauto as the one I ordered from Motor Man Fuel Injection somehow got stuck in the Swedish Customs and, at the time, seemed to be pending there for too long. As me and the family were on our way out on holiday, time was simply running out and the SMP-unit from Rockauto seemed to be the best choice, especially as it arrived within a few days. I had nothing to compare it with but it was actually branded with “Delphi” on the injector connectors. Anyway, no issues after re-assembling except for the electrical connector to the coolant temp sensor which was defect and threw a code right after start-up. Replaced it and problem solved.

Other than that, the rig ran fine throughout our holiday, except on the journey home where it seemed to be running a bit hotter than it previously had done. I will however start a new thread about this and some other new issues I have come across. The package from Motor Man Fuel Injection was finally released and arrived when we got back. This unit looked like new and I still have it in the garage as a spare, but I´ll probably try to sell it in the future.

Thank you for all your help so far! Hope to hear from you again in my new post regarding engine temperature and other bits.

Best regards!

//Johan
 
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