88 Chevrolet Truck C1500 (fuel injector)

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I have a problem with the fuel injector on my 88 chevrolet pickup with 350 engine. At time it runs fine then there are times it seems as if it's running on four cylinders. Checked the throttlebody when it's running
rough and only one injector will be spraying fuel into the engine. Had it cleaned,no change.Also while it's running rough if I can get up to a speed of about 45 or 50 mph. sometimes it will smooth out and sometimes it won't. There are times when I have to pour fuel into the throttlebody to get the engine to start.Whats possiblely that could be causing this problem? Any one.
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bobbyric wrote:

    When it acts up get a 194 bulb with some wire solider on to plug in to the injector plug, or buy a niod light. Have someone crank the engine while you check and see if the light is flashing. If the light will flash, you have pulse. Which is the signal that fires the injectors.
    If you have pulse, check out the connector for fitment, and the contacts for corrision. If the connector and the pins are fine, you need to repalce the injector, or get it rebuilt.
    If you don't have pulse you need to check the wires going to the coil, the terminals on the coil. From there you need to check the signals from the distributor.
    With only one injector lossing pulse I would suspect a bad connection, a damaged wire, or terminals need cleaned. Charles
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Do you honestly believe that the injector pulse originates at the coil?

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This is a multi-part message in MIME format. --------------090701060401040009070605 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit
It comes from a PWM (pulse width modulator) in the computer. Frank
aarcuda69062 wrote:

--------------090701060401040009070605 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body bgcolor="#ffffff" text="#000000"> It comes from a PWM (pulse width modulator) in the computer.<br> Frank<br> <br> aarcuda69062 wrote:<br> <blockquote cite=" snipped-for-privacy@newsclstr01.news.prodigy.com" type="cite"> <pre wrap="">In article <a class="moz-txt-link-rfc2396E" href="mailto:FbIcf.124538$ snipped-for-privacy@tornado.ohiordc.rr.com">&lt;FbIcf.124538$ snipped-for-privacy@tornado.ohiordc.rr.com&gt;</a>, Charles Bendig <a class="moz-txt-link-rfc2396E" href="mailto: snipped-for-privacy@yahoo.com">&lt; snipped-for-privacy@yahoo.com&gt;</a> wrote:
</pre> <blockquote type="cite"> <pre wrap="">bobbyric wrote: </pre> <blockquote type="cite"> <pre wrap="">I have a problem with the fuel injector on my 88 chevrolet pickup with 350 engine. At time it runs fine then there are times it seems as if it's running on four cylinders. Checked the throttlebody when it's running rough and only one injector will be spraying fuel into the engine. Had it cleaned,no change.Also while it's running rough if I can get up to a speed of about 45 or 50 mph. sometimes it will smooth out and sometimes it won't. There are times when I have to pour fuel into the throttlebody to get the engine to start.Whats possiblely that could be causing this problem? Any one.
</pre> </blockquote> <pre wrap="">    When it acts up get a 194 bulb with some wire solider on to plug in to the injector plug, or buy a niod light. Have someone crank the engine while you check and see if the light is flashing. If the light will flash, you have pulse. Which is the signal that fires the injectors.
    If you have pulse, check out the connector for fitment, and the contacts for corrision. If the connector and the pins are fine, you need to repalce the injector, or get it rebuilt.
    If you don't have pulse you need to check the wires going to the coil, the terminals on the coil. From there you need to check the signals from the distributor. </pre> </blockquote> <pre wrap=""><!----> Do you honestly believe that the injector pulse originates at the coil? </pre> <blockquote type="cite"> <pre wrap="">    With only one injector lossing pulse I would suspect a bad connection, a damaged wire, or terminals need cleaned. Charles </pre> </blockquote> </blockquote> </body> </html>
--------------090701060401040009070605--
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Frank S. wrote:

    No it doesn't orginate there. Most loss of Pulse issues on TBI engines are from the ignition side. Bad connections, corrioded connectors or pin, damamged wires. Bad magnetic pick ups. Very rarely does the ECM ever go bad. Could have damge wiring on the ECM side, but normially one only sees that on vehicles that have been wrecked hard. Charles
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So why send him checking the wire to the coil, he obviously doesn't have a spark problem.
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aarcuda69062 wrote:

    Have you ever worked on a GM TBI system? Charles
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Let's see... I'm ASE Certified Master with L1 GM Certified Master Chevrolet Certified Master Chrysler MTSC Former Snap-On tech rep Former Snap-On /Sun Electric regional training manager Former State of Wisconsin IM-240 referee
Yeah Charles, I've worked on a few.
Now, feel free to explain what the wiring to the ignition coil has to do with injector pulse. Use all the space you need.
I'll start you out; There are three primary wires plus one optional wire at the ignition coil 1) battery feed 2) battery feed jumper to ignition module 3) negative to ignition module (grounds the coil primary) 4) (optional) tach pigtail
Okay, you take it from here...
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aarcuda69062 wrote:

    Over qualified huh? I have no faith in ASE certs at all. I know plenty of master techs who can't even diagnose a simple issue.

    Which was the only answer I needed

    If you have a bad or dirty connector at the coil, you can get intermiant cut out. It FEELS similar while driving to loss of pulse. Takes all of 3 minutes on a remote mount HEI coil to look.
    From your attitude and the fact you feel the need to brag about your certs. I would guess your the type of guy who if your MT2500 can't find the issue For You, your running for the books. When the books don't give you the answer you start getting nervous. You overlook the simple and start breaking out every diagnostic tool you own. Then when you still can't find the issue you start verbally berating your self.
    I know ASE Master Techs like that. Not that they do bad work, but a intermittent or odd ball issue will drive them up the wall.
    Why didn't I ever get my Certs? Because to me Repair is a side line. My main focus is building Hot Rods/Street Rods, Off Highway Trucks, Competition Vehicles, and Restorations. My other Side Line, which I do Advertise is Used Parts. I don't Advertise for Repair Services. Yet people who have known me, or know about me call me and ASK me to do their repairs. I got in to Repairs for Used Car Dealerships for the quick cash & to get a way to go to Dealer Only Auctions. I got in to fleet services for the same reason. During the slow season it's easy money.
    So Ill be the first to admit, Im not the End All Be All Repair Tech. Yet anymore I end up doing everything from Heavy & Light line repairs, to body work, to supplying competition & Derby cars, to over all rebuilds of off road trucks.
    Here the Envirotest ran IM-240 emissions testing is going away at 01/01/2006. Only 4 or 5 counties in Ohio will Retain it. So Im sure my emissions work will drop to Nil. No word from the state as to any sort of replacement for emissions testing. Charles Back to work. I have to get my 58 Rambler Super ready for it's new owner to get, and R&R a th700R4 out of a Astro
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Charles Bendig wrote:

Why are you having Trouble Keeping a JOB ???

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Ah, I see...
Never having been able to exceed at anything, the concept of being promoted and/or being offered a better position or accepting new challenges computes to you as "Trouble keeping a job."
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wrote:

The OP has already stated that when the intermittant problem occurrs only ONE injector is spraying fuel, completely eliminating spark <and the coil> as a possible culprit. This is in the 4th line of the original post.
Doc
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Ya see Charles, Doc gets it and he doesn't even own a junk yard.
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"Doc" wrote:

    thanks for pointing that out. Charles
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How does one become over qualified in this business?

Of course you do, so do I, but that doesn't prove anything one way or the other about myself.

No it wasn't.

He (the OP) can see that one injector is not spraying gas. THAT has nothing to do with the ignition coil and/or its wiring.

Was I bragging? You questioned whether I was qualified because I dared to disagree with the mush you were posting.

Are you claiming that an MT-2500 will resolve all problems?

You sound like you're afraid of books. And no, nothing "gets me nervous."

You're projecting, Charles.

That's them.

Uh-huh... It was just a few weeks ago that you posted something to the effect that you were barely keeping your head above water. basically, it read that you were operating a junk yard where it wasn't zoned.

Most junk yard guys aren't.

Trying to do everything and not getting much good any anything.

Well, I certainly hope it's nothing like when Pennsylvania defaulted on their contract with Envirotest to the tune of 300 million dollars.

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aarcuda69062 wrote:

    Easy. When you spend so much time doing book work, you never get any practical experience. You eventually get to the point your on paper qualified to do anything, yet first time something not covered in your training comes up your lost.

    Yes in a way it does. You need to brag about having all these certs. People how brag about that are usually the idiots who can't get things right.

    Yes, Yes it was. Because if you WORK on GM TBI Systems enough you know what checks you should do in the first half hour under the hood. GM TBI fuel injection systems are the simplest of Electronic Fuel Injection systems. Followed by GM's MPI & TPI systems. In Emission Exempt vehicles they can set up even less complex sensor wise.

    It's on my Standard TBI check list.

    Yes.
    I asked if you had work on GM TBI systems before. Not how many patches your jacket has. I got a Jacket in my storage locker that has a patch on it. The kind that scares people. Does it have shit to do with my abilities to work on Harleys? Nope.

    Nope. A MT-2500 will give a list of codes, readings as to functions the ECM reads, and a few other dandy features. Yet too many repair personnel have become scan tool Dependant. If the scan tool can't find the fault they can't either.

    Not at all. Yet Im not overly Dependant on them, or All-Data. The only books that scare me are Chiltons & Haynes books that claim to be service manuals. When really they are all but worthless if you do more then basic up-keep.

    Not really. Im not wound that tightly. When I get stuck on a issue, Im the first to call in some help.

    That's what the Zoning papers say. Basically it comes down to Im in the Right type of zone. Industrial 1, type B-4. Which I was told originally was all I needed. Now I have papers stating I have to Apply for a Variance, go to public hearing, ect. Yet when I check in to the Regulations in 2001 I was told I did not need to go thru that, and a Variance was not needed.
    Now the Zoning Department is taking US to court. Since they want to play games like they have been playing (such as not giving written code infringements to us, just a verbal warning to the land owner), We are prepared to get legal counsel and deal with the issue.
    What the deal is: I went in on a Small Business with a few partners. We each work for our selfs yet share at current 2 locations, tools, equipment, as well as assist each other when needed.
    My one business partner is a ASE Master Tech, who did 10 years at a GM dealer. His main thing is used auto parts, while he likes to build vehicles. Another of our business partners stores some cars there that he is restoring. Between there and 2 other locations he has over 300 Oldsmobiles, and 30 Pontiacs and a few buicks. Another Partner does Harley's and pre-emissions Chevy's. From restorations to Choppers.
    My self I buy, sell and trade Cars, Trucks, bikes. My specialties are 1955 to Current GM & Harley Products, as well as 83 to current Ford Rangers, and Isuzu & Toyota's. I supply hard to find items to repair, restoration, and customization shops. I also specialize in Industrial equipment and supplies. As well as my automotive work.
    So what we really have is a property rented out to 5 people. With Space rented out to store cars to 12 other people. All told there are just under 175 Vehicles on the property we rent. Everything from parts cars, to project cars,potential race or event vehicles, to industrial equipment and supplies.
    Out of the 5 of us, 2 of us work out of the building full time. Yet the building is only 80x40x16. With the lift in the center. So it gets crampt inside, and at times scheduling conflicts make it a bear to get things done.
    So in short. Yes from a distance it looks like a full bore automotive salvage yard.
    As for "barely keeping my head above water". My overhead is more then I would like it to be. Such as the power bill that can get up to over $400 a month. Since we have a "Demand" style electrical meter on our 150 AMP Single Phase 220 service. Then their are other overhead costs that eat away at the profits. Some months I make over $4000 Profit. Other months it may only be $500 to $1000.
    In the automotive business once you are outside of Full Line or light line Repair of Stock systems. You will find business Demand fluxuates dramatically. One month I might have 6 jobs going on at once, while the next month I might only have a long term job. Long Term Jobs pay big at the end, not constantly thru out. So unless your a Boyd, a Jessie Jamse, a Foose or other well known & over booked person, you have hard times.
    I always Explore my options in life. Right now I have a few. I can go lease a Towing, Impound, Service, and Salvage operation for $2,500 a month. I can Buy a Salvage Yard with partial Inventory for $260,000 on a land contract. I can buy a Car Dealership, Towing & Impound service, and Salvage operation with all inventory, and equipment, turn key for $1,500,000 if I get financial backers. Which I am looking in to all of these at current.
    I can go back to school and get a Engendering Degree as a Mechanical Engineer, Electrical Engineer or Quality Control Engineer. If I go back to school I would not have the time needed to run my own business as I have. So working a set 40 hours a week would be the way to go. Especially if it's second shift service work. That would leave me time for at least 12 credit hours per quarter.
    Is that Crystal Clear now?

    Most people in the automotive Salvage, Repair, Towing & Impound trades do not have my work history either. Nor my education or training.

    Well I have done finish body work on two cars that have won Bloomington Gold Awards. Have provided parts for and helped advise on 3 Corvettes that have won Bloomington Survivor Awards. Not to mention some of the show winners I have helped with that took many different class wins at peigoinforge and other top shows.
    I Excel at some aspects of what I do. Others Im still above par, else wise I would send the customer to someone else. Unlike some My Ego drives me to do the best possible job, if I can't do a job to my expectations (which are higher then most customers), I don't lose any sleep over them going elsewhere.

    Ohio has had nothing but problems with Envirotest since the program began. The only way to keep from having to pay them millions the state didn't have was to let the initial contracts Run Out. Which in area's the EPA has approved the state is doing so. I don't know what the EPA standards for this were. Let alone what they will compensate with. Why Ohio let Envirotest in, let alone the IM-240 test after California did away with it, and banned Envirotest from operating in that state is beyond me.
Charles
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So, you think that sitting down once every five years and taking a 2 hour test is "spending so much time doing book work," eh? The smarts necessary for passing the test were acquired during my dealership days via the factory training centers, they tell you you're going, you go. Why not make he best of it? Not to mention that each cert got me another 15 cents an hour flat rate which along with productivity bonuses made me one of the highest paid mechanics in the county.

Is that any different than you bragging about all those supposed custom and race cars that you build?

Like I said.

Yup, and when only one injector of a dual injector TBI is not working, the last place one should look is at the wiring to the ignition coil.

Ain't a nickels worth of difference between a GM, Ford or Chrysler TBI.

Whoop!
The why of which will probably never be understood.

No. Stating my qualification is not bragging, and since you questioned my qualifications (round and round we go).

I don't have any patches on any jackets, shirts etc. Bunch of burn holes from welding flux core is about as close as you'll come...

heh-heh.... you're hilarious.

Well, I hate to disappoint you but my experience with EFI and feedback fuel systems goes back to before there was such a thing as a scan tool. Now, I truly am sorry that you find yourself befuddled with the prospect of having to be able to read and understand a data stream and other "dandy" things, but that's the way it is, like it or not, and I certainly will not apologize for knowing how to.

Certainly explains your recommendations.

I'll take your word for it.

Really? What happened this time?

Uh, no. Reminds me of the soap operas my wife watches.

Man, isn't -that- apparent.

Interesting, I was at Pigeon Forge this year and last year, perhaps we met and chatted...

Whew... you had me worried.

I don't know, I haven't worked for Envirotest for almost ten years. I can tell you that once I left and had certain conversations with state (WI) lawmakers, a multitude of false fails quit occurring.
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get a life all of you
wrote:

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Are our posts interfering with your blank screen?
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Certainly an entertaining read if I may say so! I'll bet the both of you had as much a laugh about each others abilities as I have reading the merry-go-round. For what its worth, I call this enlightening exchange of -I'm better than you-no I'm better than you- prose, a draw!
The rest has been clipped because its been dissected enough...
Respectfully submitted Rolf
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