92 blazer engine runs rough

92 blazer engine runs rough Group: alt.trucks.chevy Date: Sun, Nov 2, 2003, 7:08pm (CST+6) From: snipped-for-privacy@adelphia.net (bmaty) I'm having engine problems........ Very hard starts (like its not getting enough gas) the starter sounds good but once an a while get just a click then let off the key and it starts. Now once it gets started it runs rough. It seems good under acceleration but when at a stop sign or idling it gets rough again )it smoothes out when I drop it into neutral. I just bought it a few months ago off a close friend who had alot of work done to it in the past 2 years. And I just replaced the plugs and wires yesterday that did not seem to help. One thing that it might be is a SENSOR? while changing the plugs I found a broken sensor that I ended up breaking more. Now the engine light is on but running the same. Its a 92 blazer with the following replaced in the last year or so. with a 4.3 litre v6 fuel injected fuel pump and filter Heater core exhaust distributor cap,rotor,and coil wires and plugs good oil and filter it also needs a new radiator it a has a small leak that I just plugged up I do believe the sensor is not the o2sensor it might be temperature or something its on the driver side of the engine between 2 sparkplugs and very close to the steering wheel shaft. (inside the sensor its ceramic with a metal barb sticking out) and can send a good picture to any one interested but I do not have a website to post one. contact me at snipped-for-privacy@adelphia.net and I'll reply with an attached pic. can also send wav file of hard start.

First question what is your fuel pressure? Steve C

Actually, first question would be what letter is 8th in the VIN code. Then fuel pressure. Then I'd ask if it does this only when cold, or if it does it hot, or if it's 45 mins.-2 hours after it was last run.

If it's a W code engine, would also list L35 on the yellow sticker in the glovebox, and it's hard to start 45 mins.-2 hours after it was last run, I'd put money on the CPI or fuel lines in the plenum (AKA "nut kit") has failed.

The CPI is hard to check, but fuel pressure at specific times is a key. In the absence of a fuel pressure gauge, pull the Vortec cover off the top, remove the motor that's underneath (called the Intake Manifold Tuning Valve or IMTV) and look in the hole. If one side looks cleaner than the other, the fuel pressure regulator is leaking if it's the passenger side, or the fuel lines are leaking if it's the driver's side. Also, if you find a pattern of the hard start, when you know it'll be hard to start, press the gas pedal all the way down, puts the engine in clear flood mode and it should start better.

Of course, I wrote all that and we don't even know if the oil pressure switch is working right, or the fuel pump relay...

8th letter in the vin is a W and yes after 45min's -to 2 hours after it sits its hard to start........still working on the fuel pressure.....i'll get it just need time etc......and yes now that you mention it holding down the pedal will get it going faster. Any clue what the sensor is? Also i just found out (previous owner) the spider injection unit is only 1 year old. Installed by a Chevy Dealer. Will check Fuel pressure ASAP

thank Bmaty

No idea how to fix the roughness. But in most instances, you can braze your radiator for a permanent, and cheap, fix.... hopefully you have some friends to show you... it takes some practice to get it right. Or if need be I'll describe it for you. It's best shown though.

~KJ~

Ask if the "nut kit" was replaced as well. If not, the lines may have cracked after the stress of replacing the injector. When my injector was leaking the truck was hard to start in that 45 min - 2 hour interval, but fine outside that, yours is the same, yes?

Sensor to affect cold starting is the coolant temp sensor, not sure where that one is. I think the one that's broken is the knock sensor. I know the coolant temp sender is on the passenger side head, between

2 plugs, it's the one sending data to the gauge on your dash.

do you mean brazing as in with a tourch etc.............ive done that before but the top of the raditor is plastic thats the part thats cracked( i have a high temp/strength glue holding it for now. but its not going to last.......i can smell the fluid a little

Yes I do mean with a torch. As I said in most instances. JB weld bond should fix it fairly permanently... I've seen it used on a jag with a cracked block, haven't heard that it ever failed....

~KJ~