I know I am new but I'm really struggling with my Blazer. I have an 01 4 door with the 4.3.It starts fine...fires right up, idles good. The problem is when first fired up when its cool runs good the warmer or longer I drive it it just wont go. 5mph up a hill. Have to play with the pedal to find the sweet spot to go. When I try to push the pedal down it just all out boggs. When I let up it catches up with itself but I cant accelerate I can only just ease or remain steady on the pedal. So far I've replaced the Cat, TPS. Cam sen, Crank sen, Mass air, ICM cap, rotor, wires, plugs, fuel filter, MAP and my father in law just replaced the coil not long before I got it off of him. The fuel pressure is 60 with key on engine off and 52 at idle. Any ideas would be greatly appreciated.

 

Sounds almost exactly what I went through, for my fix it was a new spider injector, but before we get to that is the SEL on, if so get it scanned, and also check for vacuum leaks, can rent a tool at auto zone or get a hand bleeder/diagnostic tool kit from sears
link here Sears: Online department store featuring appliances, tools, fitness equipment and more
if you order a spider injector get the newer MFI type,check rockauto and I got the DELPHI part #FJ1056511B1, $230 with the new bracket included, and don't forget to Google a discount code, should cover most of the shipping

 

What is the SEL? I'll check the vacuum just didn't get a chance yet. I just hate to spend more money to diagnose something. I had it to a garage that supposedly had alot of diagnostic equipment. Cost me 160 bucks for them to tell me they wasn't sure what it was, but they thought the fuel pump, but I put it in for my in laws in the fall of 09 and there's not many miles on it. Not saying it couldn't be weak but there again I hate to spend all most 300 bucks for a maybe. I know i'll have to eventually though. I'm just trying to cover all the bases. That being said how would I know if the fuel pumps weak? Like I said earlier the pressures seem ok according to the haynes manual. Thanks for replying.

 

sel=service engine light

 

I would say if you got the pressure then its not the pump, you could also try a junk yard for the injector 03 and up will have the MFI type if you not liking the cost, but weight the used vs the new.

 

Thanks Karcinagin. I'd rather buy new but I know some people would take a chance to save a couple bucks. I hope to only do this once. Hey Blazinloud thank you to. I always called it the check engine light. I kept thinking what the h-ll is an sel. I was at work and it hit me what it may have meant....sure enough I got home and your post was up. I wont have a chance to do anything to it for a couple days but I'll post if I figure it out.

 

you may have initial pressure, but it needs to hold pressure.

 

The easiest way to fix it without spending money needlessly is to diagnose it correctly Did you perform a crankshaft position sensor relearn after you replaced the sensor? It is absolutely mandatory if you want the engine to run correctly. Next, when the distributor is moved in any way, camshaft retard must be checked and adjusted if necessary. Both of these sensors must be in "sync" with the engine and each other. Both procedures require a bidirectional scan tool.

Fuel pressure at 60psi KOEO, (Key On Engine Off) is rock bottom minimum, this thread will take you through the diagnosis: https://blazerforum.com/forum/2nd-ge...agnosis-45941/

These are all basic things that you have worked on and they must be correct for the engine to run correctly. Keep in mind that if an OBD sensor, or its circuits have a problem, it WILL turn the SES light on.

 

I am having a similar, if not the same, problem with my 96 s10 blazer lt. (all stock as far as i know minus routine maintenance: plugs,wires, oil change, etc). Slight miss at idle. On a cold or warm day, upon FIRST acceleration AFTER FIRST CRANKING, the engine boggs just as you described until it shifts out to the second gear ( @ approx 1800 RPM ). After that the engine seems to run fine until you turn the engine off or hard acceleration, then boggs. my SEL is Lit. When i reset the computer it takes abit, but the SEL re-lights. I have yet to have the scan tool run on it at oreilley's autoparts. I have spent many hours reading posts so far RE this issue, but yours is the only one ALMOST exactly describing my problem(S). I know there is alot of posts on similar problems and appologize for 'beating a dead horse', for lack of a better term. Any information is appreciated and i will continue to follow this post.

 

I did not perform a relearn. Didn't know I had to and don't know how. As far as the distrib I didn't move it all I did was put in the new cam sensor and cap and rotor. At first the thing threw out codes for random misfire and o2 sensors bank 1 sensor 1 and 2. There was also one for coolant temp low. After all I did the last time I drove it it wont throw a code at all. When I did drive it at first when it was cold or not ran very long like 5-10 min it ran good shifted good. The longer I ran it it just wouldn't go. I'd tromp it and it would go to about 2500- 3000 and wouldn't shift down it just acted as though it is against the limiter or something, all out bog. I let up on the pedal some and it smothed out, tromp bogg. Come to a hill, forget it, no power.

BTW Captain thanks for the thread. Would it be better to take it to a chevy garage for the relearn or can anyone with a bi directional scan tool do it?