Hello all. Long time lurker, first time poster. I’ve had an 01 Blazer 2 door for around 6 months now, it was in quite bad shape when I got it, but over time I have worked on it in my spare time and if I didn’t understand what I was doing, with my wallet. The issue I am running into that started relatively recently is that when I hit highway speeds, my service engine light will come on and flash intermittently, then revert to a solid. The vehicle doesn’t seem to be running worse for wear when this happens, no noticeable noises, or lack of performance.

With that being said, my acceleration is noticeably slower, but that is about the only symptom I am seeing personally, though I have little mechanical experience. This started after I replaced a crankshaft position sensor, distributor cap and rotor, and an egr valve. Brought it to my trusty mechanic and he told me it was the spider injector, which made sense to me but even with that and new plugs and wires I am still getting this issue.

Any suggestions or tips on what to look at next? I am pretty poor so cost effective solutions are most welcome and this is my daily driver so I’m really hoping to figure it out. Thanks in advance

 

I can only give general advice, suggest what I would do, and provide general comments.

First thought is that I think it is fair to say the concensus on the forum is that only AC Delco caps and rotors should be used.

Second is that doing a proper diagnosis is ideal and will likely save time and money. Have you had the OBD codes read? They can be super useful. Most auto parts stores will do this for free. If you are still stumped, be sure to share them here.

Know that sometimes the codes only give symptoms, e.g., once I got a code for a bad O2 sensor that I replaced only to have the new one fail in the same way, when actually they were going bad because they got carbon fouled due to a fuel leak from the injector assembly.

Something else to check is if there are any vacuum leaks, if any hoses are disconnected. I doubt this is the cause, but is an example of something easy to check, even if not likely the problem.

I hope this helps. Perhaps someone else will have some more specific suggestions.

 

This indicates a misfire bad enough to cause damage. The causes are endless so as Christine said, diagnosis is critical. Also, follow her advice on AC Delco only for ignition components. You are going to need a code reader capable of live data, misfire counters and reading the CMP retard parameter. Misleading misfire data can be generated if CMP retard is out of spec. Also, you are going to need a CASE relearn on that crank sensor which can also be causing bad misfire data. There are a number of code reader options:

https://blazerforum.com/forum/2nd-ge...lazers-103424/

We can help you with that but the cheapest is the BT dongle and lower cost phone app, especially if you have an android device. The crank relearn will need either a more expensive option or a mechanic with the proper tool.

We are nowhere near tearing into the spider assembly yet, if we get that far there are tests we can perform. If you want to rule out a major common issue with the fuel system with a low cost diagnostic, perform the fuel pressure test in the sticky.


George

 

BTW, George always has good advice.

 

Have to say this, find a different mechanic.
If the crankshaft position sensor is replaced or actually, taken out and put back, CKP Relearn MUST be done as the Check Engine Lite will come begin to flash and then be steady. You can reset it, and the CEL will do it again, until the Relearn is performed. I doubt it is the fuel injection spider and would not replace it until after the Relearn is performed.
As mentioned above, the Relearn requires a higher level OBD !! tool. When you find a mechanic with one and they setup to perform the Relearn, make sure they do not mash the accelerator pedal to the floor. The Relearn only requires a steady pressing of the accelerator...and will be complete before Wide Open Throttle is achieved.
After the Relearn is performed, then begin to diagnose any issues.
Good luck.

 

Dang, that's some good info, there.