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Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 15486
Experience:  Have owned a repair shop for 25 yrs.
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Chevrolet Blazer Xtreme: I bought a 2001 Chevy S10 Blazer Xtreme

Customer Question

I bought a 2001 Chevy S10 Blazer Xtreme 4.3*****in Oct 2014 with 130k miles. Truck was running fine 3 weeks ago and I did a oil change and replaced the fuel filter, checked the plugs which were clean and my son did lite driving back and forth to school with mom daily with no issues. I have driven the truck once or twice and never had any issues. Monday I took the truck out and noticed a slight hard start condition at cold engine temps, and once warm starts at touch of key, meaning it had to crank a few to start it. I also noticed that at stops and idle would get a jerk type condition, rough idle, but not all the time. When I did a WOT run from stop the truck gets to 4k rpm and pops back via the intake and the power falls off drastically. Friday evening I did a 55 to 80 run and at 4k rpm the "service engine soon" light started to flash and it was again popping back in the intake, I know this condition as a lean condition. Normal driving is fine. I put a fuel pressure gauge on it today and it has 64lbs at ignition and has no leak down when turning the key off and waiting 10 minutes. At start, the pressure hold 54lbs at idle with 64lbs on rev or hard acceleration. Was going to replace the fuel pump but don't want to waste the cash as this seems to be something else. There was only 1 code at the ECM which stated O2 Bank 1 Sensor 1 low voltage but I do not have a check engine light. Whats your thoughts on this? The truck still has the poppet type injection but for it to fail so rapidly makes no sense. I can tell you the problem after 5 or 6 test drives is getting worse, meaning that when this started it wasn't all the time and now its gotten to the point mashing the gas at 4K the problem is all the time now.
Submitted: 1 year ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 1 year ago.
Hi,My name is Tim,
I will do my best to assist you
how much fuel pressure does it have when cold and turning the starter?
again,how much fuel pressure does it have running and while driving under load?
tell me all you can
thanks
Customer: replied 1 year ago.
I already walk through this in my question, Cold, turn key on 64lbs, start/run 54lbs at idle, rev engine in park peaks to 64lbs during rev. Drive on street at temp, 54 on cruse 64/5 WOT. During leak down test, turn key, pressure at 64lbs, turn key off, walk away, come back 10 minutes later, still holding 64lbs.
Expert:  Tim's Auto Repair replied 1 year ago.
so,it will idle at 54..but,under a strain it will rise to 64psi..?is this correct?
do you also get a 300 code?
Customer: replied 1 year ago.
No codes, no constant light, had the Service engine soon light flash when doing a WOT test 1 time.. Also stated in my description... When codes were read, only found 1 which must be old as light was not on, stated OS Sensor, bank 1 sensor 1 low voltage.
Customer: replied 1 year ago.
and yes, will hold 64 at WOT
Expert:  Tim's Auto Repair replied 1 year ago.
please understand,i must ask questions to get a sense of what is going on,,i do see the desciption,
tell me,,is the engine loud from the exhaust?is it quiet?has any other work been done on it lately?
Customer: replied 1 year ago.
quiet exhaust, no other work performed on truck other than tires.
Expert:  Tim's Auto Repair replied 1 year ago.
ok
i will give you my thoughts..
i dont like the 54psi of fuel pressure,,these should never have less than 60psi at all times..with that being said,it still shouldnt be leaning out if the pressure does rise to 60psi+ when in a pull,,if the pressure is holding 60psi+ in a pull and when cold,turning the starter,this rules out the pump out the pump,though the idle pressure is low..so,do make sure of the fuel pressure,the problem sounds familiar to a weak fuel pump.
sense the engine light did flash,this tells me it had a miss-fire,if you are satisfied with the fuel pressure,tune up the engine,replace the plugs,wires rotor and distributor cap,these plug wires and distributer caps will give a fit and there is no good way to test them..
a clogged catalyst converter will also cause a similar problem and will also make the engine light flash under load,sense the engine is really quiet,you may want to have a muffler shop to test the catalyst converter
thanks
If you are satisfied with my answer, Please Rate my answer by clicking the rating button so I can get credit for my work. I’m not always going to be giving you good news, so please don't let this stand in the way of you accepting my answer. .it does not cost you more money and we will still be able to communicate, ,.please understand, i can not see, hear or touch the vehicle and only know what you tell me. Bonuses and positive feedback are appreciated.. if you are not satisfied with my answer, please do not leave bad feed back ,i will gladly opt out and let another expert handle the question. .if i have sent any diagrams, please print them. .sometimes you may need to right click the image [,then save picture as]to save it to your computer so you can open it with your picture program...Please ask if you need more help.
Customer: replied 1 year ago.
Can you opt out and run this past another technician? I understand your answers but, would like a 2nd opinion.
Customer: replied 1 year ago.
How do I test a cloged cat converter?
Customer: replied 1 year ago.
Issue resolved, found that when I did the fuel filter and checked the plugs, I also re-tightend all the clamps on the K&N filter and intake pipe, there was tear in the hose at the clamp after the MAF..
Expert:  Tim's Auto Repair replied 1 year ago.
great glad you got it
thanks
Customer: replied 1 year ago.
Well, I thought I fixed it, late yesterday afternoon when I replied back saying it was fixed, the Truck was at temp of 190, normal operating temp, I took it for a ride with my son after checking those things and it ran perfect, drove it like a raped ape for 3 miles, did stop to 3rd gear pulls, 55 to 80 runs and no issues. Last night around 8pm, I took it back out now that the engine was cold, and immediately after leaving the neighborhood, it kept doing the same thing after 4K rpm. Fuel pressure was still good, as the truck warmed up, the problem lessened but didn't go away. I don't have a back pressure tester, but I did have my hand by the exhaust pipe to get a feel of pressure at idle and then when he rev'd it. I couldn't keep my hand near the pipe it would blow it back with good force. .
Customer: replied 1 year ago.
Unsure if that helps, but the problem seems much worse when engine is not at temp, and better but not 100% when at temp.
Expert:  Tim's Auto Repair replied 1 year ago.
ok
i didnt think the maf leak would do it..
have the mumler shop check the converter...
if the fuelpressure is right and the catalyst is good,try another distributor cap and rotor
thanks
Customer: replied 1 year ago.
Tell me your opinion on this, the day I did the fuel filter and oil change, I also cleaned the k&n cone filter. I oiled the filter once cleaned and dried and put it back on. Yesterday I took the MAF off and the filter. I cleaned the MAF out with cleaner shooting the clean via opposite air flow and a snot like film built up on the honeycomb air straightener screen. I re-installed the MAF and took it for some spins. Check out these vids, no issue now. I believe I could of contaminated the MAF by over oiling the air filter. Truck runs like a champ now. https://youtu.be/LoWn98ZkrAA https://youtu.be/bh5Pd-HF5qE https://youtu.be/3NYci6-cOEs These vids are with a scanner on the O2's showing at WOT +.9 full rich/OPEN at WOT and some idles. I should of checked this as well before I cleaned it, would of been interesting to see.
Customer: replied 1 year ago.
noting after I soaked the K&N in hot water/tide detergent, the water was grossly oil contaminated. Im going to run it again today later this afternoon and my son has to drive to school today as well. I think I over oiled the filter, I coated the sensor wires in the MAF and just threw things way off. It all makes sense since this started after I did the minor maint stuff. Now on my 87 Grand National I do that stuff all the time but we are talking 87 technology and odb1 so maybe the MAF is a bit different.
Expert:  Tim's Auto Repair replied 1 year ago.
that is possible..you should put any oil on the filter,,just wash it out with water and let dry when it gets dirty
thanks
Customer: replied 1 year ago.
update - ok, so son drove it to school today, cold start 8am took to end of street, mashed the throttle and it was poppin back at WOT above 4K rpms. About 1/2 way to school, from a light, it ran fine. Today when he left school to come home, cold start it was poppin back, when he came home, didn't shut off engine, I jumped in, ran like a champ. the issue seems to be relevant to cold engine conditions.
Any ideas on that?
Expert:  Tim's Auto Repair replied 1 year ago.
yes,,
make sure again that the fuel pressure is correct,,i dont think it has anything to do with the maf.still sounds as if the fuel pump is weak and not getting enough pressure,,again,if you are sure about the pressure,,the ignition coil may be jumping spark[i have seen this,and is hard to determine]again,be sure of the catalyst make sure it isnt clogged...it is strange that you arent getting any other codes with it running this badly
thanks
Customer: replied 1 year ago.
ok, so yesterday I installed a "new cap, rotor, and plugs". Cap was hosed with white residue covering the brass on all the posts. Still have a problem but it has changed now.
I replaced the Cap & Rotor & Plugs, the cap no longer had brass colored connections but white oxidized ones. The Plugs were clean and lean but put a new set of AC delco's and gapped appropriately. Initial start was smooth and quick. Hole Shot power was good but we got the following - P0137 Oxygen Sensor Circuit Low Voltage Bank 1 Sensor 2 and a P0303 Cylinder 3 Misfire detected and that rapid flashing service engine soon light. This time no intake pops, it came out of the exhaust multiple times at the WOT shift on 1/2.
Old Cap - http://www.annapoliswebhosting.net/IMG_0682.JPG
Code 1 - http://www.annapoliswebhosting.net/IMG_0683.JPG
Code 2 - http://www.annapoliswebhosting.net/IMG_0684.JPG
Expert:  Tim's Auto Repair replied 1 year ago.
the catalyst..is it clogged?
i am thinking if not the catalyst the problem may in fact now be the spider[fuel injection unit]
thanks
Customer: replied 1 year ago.
I'm going to swap the plug and wire from 3 to 1, run it and see if problem follows to 1. If it doesn't and reoccures on 3 than I'm just going to swap distributer and then if that doesn't fix it I'm going to convert this thing from poppet to mfi.
http://www.rockauto.com/catalog/moreinfo.php?pk=984643&cc=1371440&jnid=513&jpid=8
Expert:  Tim's Auto Repair replied 1 year ago.
yes,,you can give that a try,,i wouldnt think it needs the distributor itself