Hey everyone, im a new member but not new to the site.

Heres the deal, I just recently bought a 2000 blazer zr2 with 190,000 miles for $2000 bucks... Only had a few problems.

First of all, the truck starts hard at different times. what it does is that the starter engages, it turns the motor over about 4 times, siezes completely for a second, and then starts right up.

Also, the motor runs fine when its cold and the rpms are at a steady 700ish. But after shifting into gear, the rpms drop to about 550 and it spits and sputters from takeoff until it gets to about 2000 rpms, then it runs fine. Just from a dead stop going forward or back, it almost stalls out until i get going.

4wd works fine, all lights are good, no check engine light but i did have it checked and it had 2 random misfire codes along with a bad 02 sensor.

My fuel economy is fine. 15 city, 20ish highway.

Volt meter is toast... sitting flat and dead no matter what. Not sure if that has to do with any of the other problems...

I did some research and the guy before me said it had low fuel pressure, so I replaced the fuel filter but it didnt change much. It was definitely needed to be changed though.

The plugs wires rotor and cap look new, so im not going to swap those out because it seems like a waste of money from what i read unless you know thats the problem.

Im going to do a compression test and a fuel pressure test tomorrow and will post up results. I know this is a common problem so any help on anything whether its all connected to the same thing or not would be awesome.

Thanks,-Cody

 

I'm guessing a leaking fuel injector assembly or fuel pump. You can make an adapter to test fuel pressure at the filter to see if it's the pump or on the fuel rail to see if it's the pressure regulator/injector assembly.

 

Alright, thanks for the reply. What exactly am I looking for the fuel pressure to be normally?
What would it be if the injector assembly was leaking, or what would it be doing if the fuel pump was bad?

 

https://blazerforum.com/forum/tech-a...agnosis-23038/

 

Awesome. Thanks alot, and I'll post up results tomorrow

 

Have you tried to clean the MAF sensor? You are getting pretty good mpg so it may not be a fuel issue. Maybe bad coil, spark plugs or wires.

 

What exactly do you mean the starter seizes for a second?

 

50lb_cat, I just checked the MAF sensor and it looks perfect. There is barely any discoloration and nothing in it/blocking it.

Mishimoto, The starter turns the motor over 3 or 4 times, then everything is dead silent (while cranking the engine still) and you cant hear anything at all, then a second later the starter kicks back in and the engine starts. I guess siezed wasnt a good word to choose? Im not sure.

Today I checked the fuel pressure, the truck now wont start...yahooooo! So the best I could do is turn the key on, and I tried it a few times all coming out to be 53ish... I waited 10 minutes, came back, and it was at 51-52. It barely moved at all, but still wont start.

When I say it wont start, what I mean is that it cranks maybe 5 times over and then it clicks non stop and lights flash all over until I let off the key..oh and the back hatch opens..

Maybe a bad ground? All connections at the battery are fine.

 

Definetly not a fuel problem since you had almost no leakdown. Have you checked the fuses? Maybe a bad relay? I'm not much help when it comes to electrical problems but that is definetly what it sounds like. Have you tried to tap the starter while someone else turns the key?

 

I havent at all.. It could be a bad starter I guess... I think I might jumper to test that relay. And I remember reading somewhere that I should be running 60-66psi at the fuel rail.. could this be why it isnt starting also?