Thought I'd post this thread so if anyone else starts this project they can be prepared as to what may happen.

This summer bought a 97 LS 4door 4X4 Blazer that looked good, no rust and was not beat on. Had 165K on the clock and ran reasonably well all for $1,500. I knew it needed lots of little things but I'm good at those things so it came home with me.

Only major repair that I knew was coming was the lower intake gasket. Was leaking when I bought it, no big deal...or so I thought.

While at this I had planned on new plugs, wires, cap, rotor, etc. I striped everything off that needed to come off and had no surprises and did the clean up and back together it went.

I wasn't aware of the timing reset proceedure so it took me awhile to figure things out and finaly found the DIY link on this forum. I guess I did good because I managed to hit it without knowing the proceedure.

Was time to do the first start up and it wouldn't start. It tried to but wouldn't. I double checked everything again, timing, firing order, crossed plug wires but nothing. Finaly pulled a plug and found no fuel in the cylinders so I primed the TB and it fired and ran for 30 sec. Now I know I have an injector problem but don't understand why. I never did anything to the injector.

I did the raw gas thing again and it started and ran but with a big miss in the engine. I spent the next 3 hours pouring over the threads here on this forum and realized that the spider injector was going to need replaced. Found one at the local parts store for $300 (MFI type) spent the next two hours putting it in and it's running great.

 

You didn't happen to bend over a few pins in the main spider connector did you?

 

No bent pins...That was one of the things I did the double check on. I do think that I wasn't getting good contact at the pins which may have caused the no start situation. I'm thinking that because it was after I moved the plug it started but had a dead cylinder. I then pulled the plug looking for a bent pin and didn't find any.

I did a temp test on the exhaust manifolds, or at least the best I could with the limited room, and found the driver side was cooler near the center. I looked at the poppets for that side but couldn't see anything.

The MFI upgrade did make throttle response better and it starts real easy now. We'll see how MPG does.

 

Update....

The thing starts real well in zero degree temps and with all the cold weather it still is getting about one and a half MPG better than when it was warm with the old injector. Did the new plugs and wires help too. I'd assume they did.

One other thing happened too....
After the injector and intake gaskets were done I realized the FWD wasn't working so I looked it up on this forum, did what was suggested which was reset the TCCM and it works fine now.

 

I've been doing the same job of replacing the intake gasket. I've spent several days working on it since I only get about a hour and half each day to do it, but finally got it all together tonight. I was excited to crank it up, but that's all it did was crank and not even try to start. To the best of my knowledge I did the timing right, but haven't found other post you talked about that helped. I'm hoping to figure it out tomorrow after work and have my Blazer running again!

What is the MFI that you were talking about? How did you find out your spider injector was bad?

 

This is the link to show how to get the timing set back to where it needs to be. https://blazerforum.com/forum/tech-articles-diy-29/edi-engine-timing-24373/

The spider injector problem was easy to see by checking the fuel presure after turning on then off the ignition and waiting for a few minutes and finding no residual fuel pressure. This indicates a fuel presure regulator problem. Then checking the spark plugs for any wet fuel. Then putting raw fuel down the throttle body. When it fired and ran for a few seconds I knew the injector was bad. The MFI is an upgraded injector that now replaces the OE spider injector.

Sorry it took so long to reply.

 

Sorry I'm responding even later! I got my timing problem fixed after a couple hours of head scratching. Had nothing to do with fuel injectors. Pretty much had to stick a screw driver down the tube and turn the oil pump to the right spot. This took a few trial and errors since I couldn't see at all way back there and having to go by feel. The 'ol Blazer runs like a champ now!