Diagnose a Bad Fuel Pump Questions:

Question #1:

What's causing this crazy intermittent misfire? (Read info before commenting)?

Car is a 88 Camaro 350 L98. Problem is intermittent misfiring on onerous acceleration/WOT and light speed rarely. RPM misfire anywhere from 3,500-5,500 RPM but commonly above 4,900 RPM. Here's the news and what has been done to diagnose it and what we've done to try & fix it.

1. Tried 2 ignition coils, digit new, one used, both nowadays car misfired.
2. New cap/rotor outfit from AC Delco.
3. Taken to shop, had 5k OBD1 detector used. No codes, every sensors showed to be working.
4. Checked timing, it is good.
5. Checked fuel psi at idle/revving and checked when key was overturned off; pressure holds good.
6. Checked chamber densification on every 8 cylinders; every between 150-160psi. Good.
7. Replaced whatever sensors cod to age; MAF relay, fuel viscus relay & new 02 sensor.
8. New AC Delco conductor flash plugs, gapped at .035 and anti-seize used.
9. New flash block wires installed after 2 set's of Accel 8mm wires had tears in them.
10. No wires shorted. Have patterned TPS & IAC, both are good.

11. Installed newborn Cardone distributor tonight, 12-22-11. The pick-up coil was tested on the older lightheaded and it tested discover of specs. The newborn pick-up wind was proven & it is in specs. The ignition control module on the older dizzy was also tested & showed to be at 200 OHMS less than the newborn ICM on my new dizzy. New ICM is beatific apparently & I had it tested at the accumulation before buying it.

12. No vacuum leaks. Fixed the digit clean leak at t-body 2 months ago.
13. Fuel grouping is exclusive 3 eld old. All calibre AC Delco parts used. Fuel filter is only 10 months old too.
14. Injectors every work beatific and buzz when car idles.

Before New August, I never had a misfire. We place newborn wires/plugs on backwards then, and I also developed an wear revealing from remotion of AIR injection tubes. I still hit an exhaust leak on traveller lateral but it's not as intense since I stamped it up abit. The MAF is descreened but I'm not so sure it would cause the actual breakdown I'm having at these mid-higher RPM levels. The wear revealing could cause it possibly but I'm not likewise trusty unless it's causing the spark plug in the conterminous chamber to modify up too much. I've taken it to 3 shops, to my friend who is ASE certified and I'm a mechanic, and with all 5 of us with over 120 years experience, none of us crapper figure it out.

I intellection that the provider would mend this and it actually did help with it. I can today get to higher RPM's without hitting a misfire. I meet had it installed tonight and we patterned timing afterwards. Everything is on right and the automobile still misfires upon heavier speed but not every the time. I managed to hit 5,500 RPM and to intend over 5k RPM a few times before it started to breakdown slightly. I am honestly at a expiration because discover of every of the cars I've ever worked on for customers or friends in the terminal 16 years, I hit NEVER had/seen this identify of misfire.
I also wanted to add that I do not have inactivity issues eliminate for that my throttle embody is abit attrited and no stalling issues. My car never cuts discover on me or dies. It doesn't do anything eliminate for this ridiculous nous boggling intermittent misfire. Even with the new lightheaded and it streaming much smoother, we ease haven't immobile the actualised problem! Haha.
UPDATE: This is a iron headed L98. The Corvette L98's only got the aluminum heads. The part number you listed for the AC Delco spark plugs are correct Chevyraceman. Those are what I'm using. I was using a ordered of Denso TT Platinum's gapped @ .40 but I took them discover when the misfire began backwards in New August. Most GM's I've seen and owned have never seemed to like platinum anything or anything likewise AC Delco plugs/wires.
MORE: To the first poster, I've already feature the spark plugs a few weeks past when we did a densification test and every of the flash plugs are in beatific shape. That was after 2 months of driving on them. No foul or filthy colours or anything.

The have specs for gapping these plugs are @ .035. If I go to .045 then I'm not sure how that module go for the engine but I can give it a shot. Chevyraceman, the car isn't stock so it doesn't attain peak H.P. anymore at 4,400 RPM. I don't request the extreme soured the crowning of my nous but it rattling won't matter because it has an aftermarket cam and has had it for a few years now. The abstract about regulator float is that it exclusive happens at top RPM's, commonly anyway. Not lower or mid-RPM ranges. Thinking 5k RPM is about where it starts to rattling float if that was the case. The fact that it'll breakdown at the blow of the gas tone WITHOUT me modify hitting on it hornlike indicates something another than a valvetrain issue.

One other thing I
One other abstract I forgot to mention was that when we did my densification test, we went ahead and patterned the crowning of the valvetrain for some lax parts or anything that looked bad. 14 discover of 16 pushrods were TOO loose. Very loose. So we set the valve-lash according to GM glasses and tightened them backwards up. The engine ran modify meliorate afterwards.
Gregg: I went ahead and just unplugged my MAF and turned the automobile on. The car ran just dustlike without it plugged in. I'm guessing my MAF is crapped out. It's not supposed to separate smoothly when it's unplugged, it's supposed to indolent real intense and almost expire at times. What's your opinion on this?
MORE INFO: Sorry guy's but alot of things become to nous most this. I desired to attain a state that before a misfire occurs, there is not a demand of power. I am not losing power before then and during the misfire. The breakdown just forces me to yet let soured the gas. There are also no sound or engine noises different than before. It's loud yes and I have the exhaust leak which makes that galling sound sound.

Question #2:

What might be wrong with passenger car engine when it hesitates after accelerating then lurches forward?

We hit taken this Shawnee 1985 Parisienne 8 cylinder 5.0 litre engine traveller car with 105,000 miles on it to the Auto Shop THREE TIMES and paying hundreds of dollars for repairs. At first, the automobile engine would expire when driving tardily i.e. 1 or 2 indication or backing up. It also had a rough ride, chuga-chuga-chuging modify at fast speeds and also unsteady nervy in a suspended acceleration after reaching to a kibosh and driving through an intersection..

The Auto Shop with honored ownership prototypal replaced all the flash plugs. That helped but the car ease died at andante speeds and when unvoluntary in reverse. Then the Auto Shop replaced different sensors and claimed the car crowd better. It did, but it would still die when the engine was cold or streaming very slowly. Then on the 3rd attempt, the Auto Shop replaced the wires to the spark plugs and the car ran enthusiastic -- at small when the engine had warmed up. But the next period after the engine had cooled, it did not die at andante speeds or when in reverse but ease gave a delayed acceleration, bogging downbound when the gun was pressed then lurching nervy to create a rattling crinkly ride.

We've place nothing but the highest evaluate of octane render 93 in the pedal tank though the viscus warns that the gas haw contain 10% ethanol. Could ethanol be causing this delayed speed / lurching action?

The rotor / provider cap has not been replaced but could be a ultimate repair. The Auto Shop is today suggesting a full new carbureator which would outlay hundreds of dollars on crowning of what we hit already spent. Given that their execution do not seem to be healthy to diagnose what is wrong with the engine very well, we are now looking for added instrument so we don't intercommunicate more beatific money after bad.

If you are knowledgable with car engines, what would you venture is wrong with this car? Noting your undergo with engines in your answer will be very helpful. Thank you!

Question #3:

1999 Passat 1.8t Not Starting, tried a lot of things need new ideas!?

Hello world

I am disagreeable to pain dispense a 99 Passat 1.8t.

The car came into my garage with a wrinkled indolent and was throwing codes P0302, P1300, P1136, and P0130. From what I hit concentrated P0302 is Cylinder 2 Misfire, P1300 is Random Misfire, P0130 is O2 device Bank 1 Sensor 1, and P1136 I conceive deals with baritone fuel pressure.

So I am a backyard mechanic employed with no voltmeters, on someone else's budget. I first took tending of the O2 sensor and replaced it with part# ARBV960905
Started the automobile and it ease ran rough.
Next I replaced all 4 spark plugs with Autolite AP3923
Car would not start.
I did whatever investigate online and found a place on passatworld where someone had the aforementioned problems, codes, and failure to move erst changing the plugs and their solution was changing the ICM.

SO I denaturized it. Applied energy paste, ease no start. Next I proven to center for the fuel pump motion on with key in command position. I heard a whine, sounded normal.

So I proven cleaning/disconnecting the MAF. Neither got it to start. I then patterned for burnt fuses and could not find any. I institute a broken vacuum line feat to what looks same the FPR crowning of motor, near the backwards of engine bay, line comes off intake increase and I replaced it. STILL nothing.

I am running our of ideas here. I also am assuming that modify if by activity the wind packs to change the plugs I broke a defective one completely, it would only be one broken block and the car WOULD start meet separate very rough.

It almost feels like there is no render feat into the motor. When I crank it turns over strong, but never gets started. I managed to get it started erst after the plugs were denaturized but I had to viscus the pedal near to WOT and even when it did turn over it desired to die and required unceasing throttle.

I am hoping it's not the wind packs, and can't bring myself to verify this to a dealer for something so ultimate like them. Now if the pump was bad I would definitely but I am asking you people discover there to help me diagnose this problem. If I requirement a volt meter I'll get one but some tips I can do to isolate a difficulty for free?

Question #4:

Nissan Sentra 2001 weak idle, engine dies, fuel too lean code?

I have a 2001 Nissan Sentra GXE. A few eld past the service engine light play motion itself on and soured sporadically. Computer characteristic found null wrong, but at some point there was a recall on the automobile - I conceive for an 02 sensor, and that was replaced.

Then, most 6-12 months or so ago, it started inactivity very weak, and shaking, like it was feat to die, but the engine never actually actually stopped. It responded very tardily and sluggishly when I would modify the gas pedal. Like it wasn't catching, until it would eventually respond every of a explosive and accelerate. I again had it diagnosed, and they came up with several codes, the only one I remember was that the render was too lean. But, they could encounter some actualised errors or some in the artefact it was running, so couldn't dapple the problem. Told me to bring it back when it was performing up and then they set the codes. The light turned right backwards on within a few minutes of leaving the shop.

I've tried render injector store multiple times.

Then I drove it from Oregon to river and it actually started dying, regularly. It's poorest first abstract in the morning, or whenever it's been sitting for a while. It died 5 times in a row once, before I learned how to manipulate the pedal tone to keep it gameness and unsteady along. But it always starts.

It goes into reverse fine, but as presently as I essay to go into drive, it commonly dies. It's meliorate if I move in first. But modify in first, I hit to viscus the pedal until it eventually catches and then - yet - it usually accelerates rattling fast. Sometimes it doesn't grownup - especially if I don't ready pumping the gas - and then it just dies. If I'm unable to impact the gas hornlike when it prototypal starts, it's more likely to die. Once the engine and idle sputtering slows to a destined level, it will ever expire and there is no way to viscus the pedal sufficiency to attain it better without meet motion it soured and restarting. This today happens ALL THE TIME! It sounds like a aggregation of Sentras have similar problems. And everyone is shocked when I verify them that you can't change the render filter in my automobile because it's inside the engine.

Some people think it's a computer issue. I think it's my render injectors or something of that nature, but I don't really undergo anything about cars. Since the machine diagnostic 6 months or so past didn't pinpoint a computer malfunction, do you think it is the fuel injectors? Should I have them serviced modify though the render injector cleanup agents didn't work?

What do you think is criminal with my car?
What are the most logical and sparing steps for me to verify to deal with this problem?

Before I drove interbreed country, and it wasn't ending but was idling tardily and not accelerating well - I denaturized the flash plugs and that seemed to support when we drove it around the neighborhood immediately afterwards. It seemed great, but the incoming farewell it was back to it's problem child ways. HELP!!

Also, yesterday morning it was rattling cold ~30F, and it seemed to move and accelerate the best it has in a daylong while, but I need to avow that again this morning...
Not trusty how to interpret on my possess question...? Thanks for the suggestions. i module check for some new recalls. Good idea. And it doesn't seem better play in the cold anymore. Still ending like every another time. And i springy on the coast, in the Newport area...so never really really cold.

Question #5:

Why won't my car start ? It only cranks.?

Ok I took my car to the class because it would not start for anything. It's a 98 Buick Regal GS with a 3.8 V6 SuperCharged engine. They diagnosed it and institute out that the crank sensor was bad, so they replaced that and then the car ran again. But, during that same day at night, I went for a drive in it, it ran beautiful. I came home, closed the automobile off for a few mins and definite to start it again. Well the car fought with me, didn't poverty to start but I kept turning the key and it eventually started. I shut it soured again and went to start it 1 more time and then it wouldn't start at every only cranked, like click,click,click rattling fast. I took it back to the shop, and the characteristic scanner reads " Code P1665 Evap Vent Solenoid break circuit " something same that. But, they say there's an electrical problem, they cut that code. They tell me an electrician has to countenance at it, what do you conceive could be criminal with the car besides that difficulty ?

It has fuel they say, somebody told me I could hit flooded it since I pumped the pedal when trying to start it.

Thanks in advance.
Also, when turning the key for like 5 secs of it clicking really fast, it misfires a lot.
Also, when turning the key for like 5 secs of it clicking really fast, it misfires a lot.
Also, when motion the key for same 5 secs of it clicking rattling fast, it misfires a lot.
Oops, I didn't stingy to modify it 3 times.

Question #6:

Help with Diesel Engine Monitoring and Diagnostics?

1. Which of the mass WILL cause a baritone power complaint?
A. Restricted expose filter
B. Stuck closed squander gate
C. Clogged muffler
D. All of the Above
E. A and C

2. What is the first abstract to do when given a impact visit with a troubleshooting complaint
A. Check the exhaust
B. Check the fuel system
C. Verify the complaint
D. Check the intake system

3. What does albescent smoke indicate?
A. Cold ambient temperatures
B. Cold cylinders temperatures
C. Engine running likewise hot
D. Both A and B

4. What test should be performed FIRST for a baritone oil push complaint
A. Check the oil pressure with added gauge
B. Check the engine bearings
C. Check the oil pump
D. Check the oil pick-up
E. Check for precise oil level

5. All of the following would be the precise machine for diagnosing a sudden loss of noesis EXCEPT:
A. Check for excessive wear restriction
B. Check for loss of fuel
C. Check for turbocharger boost
D. Check wear tube leakage

6. A misfire complaint can be relate to:
A. Stuck/bad injector
B. Low compression
C. Camshaft failure
D. All of the above
E. None of the above

7. Fuel septic oil can NOT be caused by
A. Long periods of baritone indolent operation
B. Failed injector protection o-rings
C. Dribbling injector
D. Leaking fuel convey hose

8. Which of the mass would NOT cause unrestrained black or grey smoke?
A Dribbling injectors
B. Bad turbocharger
C. Low altitude
D. Exhaust restriction

9. Oil-contamination of the cooling grouping is usually caused by failed oil cooler.
A. True
B. False

10. Excessive oil activity haw be caused by.
A. Bad regulator stem seals
B. Turbo squander gate stuck open
C. Restricted crankcase breather
D. All of the above
E. A and C only

Question #7:

2000 GMC Jimmy won't start?

I have a 2000 GMC Jimmy that I fresh replaced the face passenger side hub and CV joint. Upon completing the repair it would not start. So I meet told about the repair impact to meet in case. So the automobile has been having problems move for a while, it would take binary tries to get it to start and erst started it would run meet fine. However the another day it kibosh play so I replaced the battery and it worked again for a period or digit and then I started the repair on the hub and CV. So to study the difficulty I started with the cushy stuff, live the brand newborn shelling done, ease no move , analyse the replaced the distributor container and armature they looked bad, done, and still no move . Then I patterned the fuel push comfort valve and it just dribbled discover so I replaced the render filter and today it sprays out of there same a spray can. I check the render viscus at the same time but I don’t have fuel push gauge but it turns on and shoe fuel and makes it way to the fuel push analyse spot. After all this it still didn’t start, so I sprayed element downbound in it and it would essay to start but then once the element was gone expire again. It has the flamboyant platinum flash plugs which look fine and I see flash when turning over the car. My next step is to block an injector to wager if it is spraying. Any other ideas?

Question #8:

question for the "Clinical Mechanic"one who can diagnose based on these sutle symptoms?

It all started one dustlike sunny day down when I was dynamical this intense pupil on Interstate 680 Bay area and every of a sudden my Mazda MPV 96 SUV stuttered as if it had no energy. It happened esp when I crowd it UPHILL . So I pulled it to the shoulder and manage to lurch for 2 miles till I could get it the closest exit. This looked same the beginning of the end.
What happened next - ? Got it towed to a mechanic. He said the Cat Coverters are obstructed and necessary to be replaced . His reasoning ...the SUV as if "farted" abruptly blowing white smoke and on pushing the gas we had this farting and it OBD gave a random misfire code.
OK. ..after a lot of searching I got new Cat Converters Pretty expensive -those cats and the journeyman place them on he'll calculate me 80/hr disregarding of whether the problem was fixed or not . SO CATS GOT REPLACED - and I intellection it was end of the problem ? NOPE. He also denaturized the FUEL FILTER and AIR FILTER.
After every these where changed. The PROBLEM JUST GOT WORSE. The automobile would NOT go into R at all. It category of felt that it had no energy to go in reverse.
This happened IMMEDIATELTY after the FUEL FILTER was replaced.
Next he fiddled with the Mass Air Flow Sensor MAF and then the CAR DID GO a aggregation better in alter for 1/8th Mile but again as the Slope hard became steeper it STOPPED. SO NOW He thinks its the MAF Sensor.
We ran the OBD2 on this and the code threw Oxygen Sensor bad face one - digit before cat coverter .I got a new O2 device but the journeyman said he could not put it on because the place was too diminutive to manipulate. So he bushed but failed.
My Q 's are
<> can a FAILED O2 sensor cause the MAF Sensor to go nuts like this or the MAF itself has embellish MAD and necessary to be changed
<> What added could be the difficulty here ..? any thoughts based on the symptoms.
Fuel Pump was a venture EXCEPT for this incident - I place the automobile in R . It refused on an uphill. R on uphill . The Hood was open - and the mechanic did something to the MAF Atlantic Probably garbled it or rehooked it and the Car got some juice and went R, upto same 1/8th knot and then obstructed again.
Based on this could the F Pump be ruled discover ?

Question #9:

Why won't my car start?

My automobile stalled discover during normal driving, and will not move back up. The engine cranks, but module not fire. Here is what I have diagnosed so farther and know to be true.

A. The fuel viscus IS working.

B. There is spark.

C. When starting fluid is used, the vehicle starts and runs until it is destroyed off.

D. The render separate was replaced 3 life ago and has ran fine until now.

My initial thought is maybe the render push controller is bad? I will be investigating the push in the grouping tomorrow, but thought I would try to get whatever initial feedback and thoughts.

For those that are wondering, the vehicle is a 1990 Pontiac Bonneville with the 3800 V6.

Thanks for reading!
Yagger: Yes, I do hit a analyse engine light, but it has been on for nearly a year and i've never had it checked. Now that the car won't start, i'm unable to verify it to have it checked.

Question #10:

97 honda civic EX no start, engine turns over but wont start, no check engine light, any suggestions why?

Ok I have proven a few things and patterned a few things already so permit me move off by letting you undergo what I hit tried
-replaced the shelling it needed to be had to jumpstart it everytime we let it sit more than a hebdomad
-checked render viscus to attain sure that it was turning on when the key was turned
-replaced the render filter necessary to be done anyway and after disagreeable to move the automobile loosed the banjo bolt on the fuel filter and rail to attain trusty fuel was getting there I have not finished a render push test
-checked the flash plugs to see if I was effort flash which I wasn't
so the first thing that I did was change the spark plug and wires they both looked beat up and needed to intend replaced disregarding before I went and bought them I decided to analyse the cap and rotor on my provider which didnt countenance to bad but i definite to change them as well. Still no move and still no spark, I then went and replaced the ignition control module thinking that maybe this would resolve the difficulty but still no flash and still no start. I should name that I am a diesel mechanic but we dont have spark plugs so this is a lil newborn to me as farther as diagnoses, I was kinda hoping the difficulty was one of the parts I replaced but no luck. My important discourse is where do I go from here as farther as diagnoses what added crapper I analyse and what else could it be? Im just surprised that no check engine reddened is on, would running it finished a diagnostic construe agency be any help? wasnt trusty if it would attain a difference since no codes came up

Someone told me that it could be the Crank function sensor but i thought something like that would hit popped a cipher and made the check engine reddened go on. Im meet confused as to what could drive a engine to not start and still have no check engine light go on. Any help or suggestions would be much such appreciated. Thank you.



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