Fuel Injector Question / Rough Idle / Loss in acceleration

[donr1963]

hope someone can give some advice as to what to try next. I have a 1988, 6 Cyl. 4.3 Astro van, awhile back I did a full tune up (rotor, dist. cap, plug wires, air filter, plugs, fuel filter, oil filter, oil change), the van ran fine for a few weeks and then I noticed that during complete stops the idle became rougher and rougher it got pretty bad and it worsened over the weeks and got bad enough as to where I didn't want to take the vehicle on the road to avoid getting stuck. This past week I took it to the shop where they had installed a rebuilt engine in the van about 2 years ago. The mechanic there ran a diagnostic on the van and said he noticed one injector was malfunctioning, the spraypattern was off and it had a small steady fuel stream from the center of the injector pouring right into the butterfly valve (I hope that's the right description), anyways I guess I'm like alot of people that want to try to keep costs down and do it yourself helps alot. The part number on the original injector that's defective is GM5235134*RPD, at the other side of it there is an additional number 9167 GM. I contacted the local Autozone and took the part with me to compare, they entered the number and said it was a Borg Warner part, unfamiliar to me but they suggested the equivalent would be a GP Sorensen 800-1801N, Autozone actually offered 2 injector types but couldn't give specifics in the difference, just the ending part number, of course the viewing both, they looked exactly identical. I did notice immediately that the injector tip was different, the original has a small tiny opening at the end, as to where the suggested replacement has about 5 small openings, they seem recessed and it seems to have a small cone pattern inside the tip going towards the openings. I replaced the defective injector, gaskets, checked for leaks and fired the van up, it still showed a rough idle but I then noticed what seemed like small misfires inbetween the idling. The thought was since the engine had run bad that the plugs might be fouled so I went today and got new plugs and replaced them, the old ones are extremely dirty and black. After this the van had a pretty good and smoother idle. The problem I noticed was during a test drive that when I took it onto a main road and went to accelerate that the pickup during acceleration has noticibly decreased, so I'm wondering what to check next. I know that even when the bad injector was still in place that my van would have extremely good pickup and go. I would be grateful for any suggestions to help me get my car running good again.

[GMMerlin]

If you installed an incorrect injector, that may cause a lean condition and loss of power on acceleration.

[donr1963]

Thank you for your response. I've had that suspicion but the problem that I'm running up against is that Autozone cannot exactly tell me what the difference is between 2 injectors that they have that could fit my van, 1 injector has the Autozone part number 17111928 and the other is part number 17111929, they look exactly identical, the only difference noticable is the price, there is no technical information included with the injectors and I am unable to retrieve any specifics off of the internet for the original injector. The part that Autozone suggested was the 17111929 which was first the cheaper of the 2 parts and second according to Autozone, the GP Sorensen 800-1801N is the equivalent to the 17111929. Would you have any suggestions as to what could be used to replace the defective part that can be obtained without necessarily having to go to the dealer (part number and brand would be an excellent help).

Thank you again.
- Don

[GMMerlin]

You can call the dealer parts department and get the part number or try
www.gmpartsdirect.com

Thy will give you a good price, but watch the shipping charges

[RABarrett]

These described issues seem to be the pursuit of an untamed ornithoid. The problems described by the originator of this thread seems to have more than one issue, and the focus on one injecor seems tedious. When the engine runs rough, can the problem be isolated to one or more cylinders? If the engine is generally running poorly, other issues are possible. My suggestion is that we approach this problem, systematically, and proceed based on the results of testing. First, let's determine whether the issue os traceable to one or more cylinders. Injector issues are typically traceable based on the failure of certain cylinders, just like a carb. If cyls 1,4,5 or cyls 2,3,6 are the problem, suspect an injector. Otherwise, I would suspect other possibilities. Ray

[donr1963]

Originally Posted by RABarrett

These described issues seem to be the pursuit of an untamed ornithoid. The problems described by the originator of this thread seems to have more than one issue, and the focus on one injecor seems tedious. When the engine runs rough, can the problem be isolated to one or more cylinders? If the engine is generally running poorly, other issues are possible. My suggestion is that we approach this problem, systematically, and proceed based on the results of testing. First, let's determine whether the issue os traceable to one or more cylinders. Injector issues are typically traceable based on the failure of certain cylinders, just like a carb. If cyls 1,4,5 or cyls 2,3,6 are the problem, suspect an injector. Otherwise, I would suspect other possibilities. Ray

Thanks again for the replies, Ray... I appreciate your interest in my problem and would pursue troubleshooting the failure of any cylinders if I knew the steps. I do know that I've replaced the original defective injector with 2 incorrect suggested GP Sorensen injectors, neither of these resolved the problem to 100% satisfaction, I know that when the defective injector was in place that the vehicle had a problem with the idle during stops, otherwise on the open road it had excellent pick-up and acceleration, this reversed after I replaced the defective injector with the GP Sorenson parts. I've been helped forward a great step by GMMerlin with the website offered for the GM parts and have done some research, apparently this injector cannot be purchased at just any parts store or Advanced Auto nor Autozone, it's not a part that's readily available and through further research I've found that Partsamerica.com was able to assist in finding a Borg Warner - Niehoff part number 57207 which is identical with my defective injector, the visual on their website is identical and speaking to different technicians there they utilized the old GM part number and all identified the 57207 to be the replacement injector for my vehicle. I've ordered this part today and the total cost with regular ground shipping cost, is actually somewhat less than what I paid for the replacement GP Sorensen which didn't work. I should have the part by latest 1/29 and hope to report a vehicle that is in satisfactory running condition and the problem eliviated.

[RABarrett]

The easiest way to determine which cylinder has the problem is to one by one disconnect the plug wires at the cap. Be careful of getting shocked. If the cylinder you disconnected affects the engine's performance, that cylinder is ok. If it has no effect, that is one that is misfiring or not firing. You can check for spark on that cylinder by gently pushing a screwdriver into the plug wire end and hold it close to the block. A spark at that point indicates ignition to that cylinder. We'll start there. Ray

[comp]

good info, to add when you do the running cyl. test by pulling a plug wire
ground it

[donr1963]

I will check to see that all plugs are firing if problems still occur after I've received and installed the new replacement injector, I'm pretty cautious about handling plug wires, it's a feeling that you don't easily forget. Thanks for your quick reply Ray....

[astronot]

Did the new part 57207 work for you? I'm having a problem with rough idle and loss of acceleration/rough accelaration, and likely will be ordering the same part. http://www.partsamerica.com/PartDeta...rtNumber=57207

Thanks!

[mcknt]

While looking at the plugs, you may want to also check the wires for arcing. I do this by two methods: 1. In a real dark area, look for the blue arcing across the wires. If you see it that way, the wires are real bad. 2nd method, get a bid screwdriver with a well insulated handle. Attach a wire between the screwdriver and a good ground. Run the screwdriver along the wires with a little distance between. If you see a blue arc jump between the wire and screwdriver, you've found a bad spot.

[Tiger77536]

Hey Astronot, you posted the question about the fuel injector in my forum but I couldn't sign in to reply so this is for you buddy I hope it works. Anyway to your question, the injector that I got at parts America worked excellent BUT before I found that out here's what happened. I installed the Injector from Parts America but still had a rough Idle, sort of frustrated and short of shooting my car to put me out of misery I took it to the place where they originally replaced my engine and had them check it through, a freak thing happened that never occured to me, the rough idle was still occuring due to a material defect in one of my spark plugs that resulted in a crack, they replaced it and my car runs like a charm but I know that the other attempted Injectors did not work on my vehicle, with or without excellent plugs, the only replacement that works is the one mentioned from Parts America. I hope this helps you.