Drivability issues

[Blackened87]

I just recently picked up a one owner 87 GN and I been having a issue with it. The previous owner said the car was sitting for a while so he got it running by installing new plugs, wires and a new coil. Once it started, it was running rough so he installed all new 30psi accell fuel injectors which he claimed solved the running issues.

It however did not help when driving. When I go above 5psi of boost, it starts breaking up and hesitating bad. I don't hear any pinging, just starts loading up and sputtering. I let off the gas and it has to catch itself to keep running.

The idle is better when warm then cold. The cold idle is rough and almost feels like it wants to stall, it's a little better when warmed up but not much.
So far I pulled all the plugs and saw that the gaps were way off at almost .050! I re-gapped everything to .032 and it runs a little better but still has the sputtering over 5psi. I picked up a good fuel pressure regulator and that didn't help either. I tried tapping on the MAF and the idle didn't change, I also ran it with the MAF unplugged and it ran worse.
My next plan of attack is to check the fuel pressure, change the fuel filter, and smoke check for vacuum leaks.
I installed a scanmaster and it starts working when driving, then turns off when stopped at a light. The information it's giving is inaccurate and all over the place so I'm thinking a new ECM is in my future. Also the engine cooling fans do not work, the relays look like they were replaced in a attempt to repair it, but it still didn't turn them on. A new coolant temp sensor is also in the works and I was planning on replacing the 02 sensor since it looks original.

Any other things I should consider or has anyone else experienced the same issues?

Thanks for any info.

 

[cbird77]

Go and read on the Vortex Buick turbo website. Read and take notes...this site is a must read for owning and maintaining one of these cars. Definitely check your fuel pressure.

 

[MAK507]

New coil pack, did he get a new ignition control module while he was at it?

New injectors, how about a walbro fuel pump?

I was having the same issues so I swapped out everything.

New walbro fuel pump
Racetronix fuel pump hot wire kit
Adjustable Fuel pressure regulator (mine is an Accufab, wish I would've gone with Kirban-too many horror stories with Accufab from other board members) ...
TurboTweak chip from Eric.
If that doesn't do the initial job, then go to new ECM.. Which I did as well.

The ones I listed are must haves.




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[quikv6]

Perhaps I missed it, but I saw no mention of what chip is in it. Make sure the chip is properly matched to the injector size. Also, verify TPS is properly set, and not over .46 at idle.

 

[GnJoe87]

Sounds like a fuel related issue, verifying the running pressure is the right idea and a fresh filter wont hurt. Also make sure your the scanmaster isn't tied into the brake switch. My car did the same thing when I bought it and that was the case. If your scanmaster shuts off when you hit the brakes you need to wire your 12v to a 12v ignition source not switched.

 

[Gene Van Horn]

Call Dave Husek in long island, or Jim Dunn outside of philly. Make an appointment and get the car to one of them,either will get it running properly. You may think its just one simple thing,and once in a great while it is. But most likely its a combination of a bunch of things, they are equipped with the knowledge and experience to deal with all the issues and get your car running the best it will.

 

[Blackened87]

Thanks for the information.
It's a stock chip in a replaced ECM. I'm not sure when it was replaced, I just noticed the sticker on it was newer. I did notice on the scanmaster when it was working that idle TPS voltage was showing 4.8, I'm not sure how accurate that is since its been showing immaccurate readings for load and other parameters. The injectors are accell 30psi which I read as being a stock replacement. I think the originals were 28 or 29?

As for the ignition, he just replaced the coil, delco wires and delco plugs all gapped incorrectly. I fixed the gap issue but the module was not changed.

I used the 10amp ignition fuse as a power source for the scanmaster, it's powered up, but it seems to lose communication when I'm stopped and then will work again when driving. I have to get it up on a lift to check the battery cables running under the exhaust and the wires on the starter to see if they are the cause.
Tomorrow I'll replace the fuel filter since it looks old and I'm getting the fuel pressure checked on Friday. The fuel pump I believe is stock and may even be original. A walboro with a hot wire kit is on the to-do list.

Once I can confirm its not a fuel issue then I'll order a module with new plugs and wires. Some of the plugs I removed were a little wet. I'm thinking the wide gap may have been the issue. There was a little popping in the exhaust at idle which the new gaps cleared up. Now it's just the drivability issue under boost I'm working to get sorted.

Thanks for the advice. If I can't seem to get it worked out, I'll certainly be looking for a shop that is familiar with these cars and get it worked out. I just wanna cover all the basics and see if I can get it resolved myself.

 

[MAK507]

Well, lay off the boost until you figure it out. If it is a fuel issue, you'll run into trouble under boost!

The stock regulator and stock fuel pump were barely providing sufficient fuel.. Your injectors are larger than stock.

Trust me man, I've been there trying to save as much $ as I can. But it only leads to other issues. Now that I've replaced the necessities at once, issue is gone. The car is old as hell, needs upgrades regardless. Your ABSOLUTELY necessary list should be fuel pump, hot wire kit, adjustable fuel pressure regulator, and turbotweak chip to match the injectors, and turbo. Since I was getting a turbotweak chip I went ahead and got the 3" ls1 maf sensor and maf translator. I also got a new intake filter.

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[Blackened87]

Thanks for the info. The theme for this car is to keep it a stock original car. I have other cars that I spent plenty on performance modifications, this car is special to me so I'm just looking to keep it as original as possible. Just getting it running right is top priority!

The fuel pump is certainly on the list with the hot wire kit. I put a stock fuel pressure regulator on it for the time being in a effort to improve drivability. I haven't pushed the car at all, I also haven't heard any detonation or pinging when it breaks up, just runs like crap then it has to catch itself from stalling which I do agree does sound ignition related.
I do wanna put the money into the car for the reliability upgrades since the car is absolutely mint and worth it but I just don't wanna throw parts at it and hope for the best.

Is Kirban performance a reputable seller for parts? I ordered the scanmaster from them and was going to put a list together and make one big order for all the ignition parts, fuel pump kit, and the small misc items once I get a idea what issues need to be resolved.

Thanks again for the information.

 

[That GN Guy]

Go to http://www.turbotweakstore.com and get a new chip for your pcm. Your chip MUST match your injectors for wide open throttle applications. You can't "upgrade" injectors without modifying the computer that controls the injectors. It might start and run fine driving around, but in the boost range it's important that everything is lined up right or it's just wrong. Too much fuel= sputtering and brown smoke out the tail pipe. Not enough fuel = knock and new engine.

Going from stock injectors to 30lb injectors with no further modification means you will run rich all the time. The pcm will learn how to idle and cruise, but not run WOT without issues.

 

[Blackened87]

Go to http://www.turbotweakstore.com and get a new chip for your pcm. Your chip MUST match your injectors for wide open throttle applications. You can't "upgrade" injectors without modifying the computer that controls the injectors. It might start and run fine driving around, but in the boost range it's important that everything is lined up right or it's just wrong. Too much fuel= sputtering and brown smoke out the tail pipe. Not enough fuel = knock and new engine.

Going from stock injectors to 30lb injectors with no further modification means you will run rich all the time. The pcm will learn how to idle and cruise, but not run WOT without issues.

I would agree with you that if I went from stock 29psi to 42psi injectors that the system needs to be modified and I'll need a chip. I went from the stock 29psi to 30psi which is hardly any difference at all. These injectors are considered stock replacements, if anything, the tired old injectors didn't put any strain on the old pump and now that they are flowing properly, the pump may not be able to support it or my ignition is breaking up under load.
I'll have to get the fuel pressure test to confirm where my next step is. I just feel a chip isn't needed at this point until I get the drivability issue sorted out first.

 

[No disintegrations]

fwi

I would agree with you that if I went from stock 29psi to 42psi injectors that the system needs to be modified and I'll need a chip. I went from the stock 29psi to 30psi which is hardly any difference at all. These injectors are considered stock replacements, if anything, the tired old injectors didn't put any strain on the old pump and now that they are flowing properly, the pump may not be able to support it or my ignition is breaking up under load.
I'll have to get the fuel pressure test to confirm where my next step is. I just feel a chip isn't needed at this point until I get the drivability issue sorted out first.

fwiw injectors are sized by lbs/hr, not psi. Different brand or style injectors of the same size can run poorly if the chip is wrong for them. Do you have a pn for them?

Double check the coil is wired correctly underneath. the green blue yellow wires going to the module. It's free and could give trouble if wrong.

 

[Blackened87]

You are co

fwi

fwiw injectors are sized by lbs/hr, not psi. Different brand or style injectors of the same size can run poorly if the chip is wrong for them. Do you have a pn for them?

Double check the coil is wired correctly underneath. the green blue yellow wires going to the module. It's free and could give trouble if wrong.

You are correct, lbs per hours, not psi.
They are accell 150630 fuel injectors.
The previous owner bought them from Summit racing.
I pulled the coil up and the wires to the module are correct according to a picture I found online.

Now here's another issue that's probably my problem all along. I was noticing that my scanmaster would turn off when I hit the brakes, I got a test light and tried to test the fuse and see if it's breaking power when I step on the brake. I used the 10 amp ECM/IGN fuse as the power supply for the gauge. I get under there with a working test light and I can't get the test light to light on that fuse or any other fuse either. I start the car and the test light works and I'm able to test the fuse. When the test light goes out, the engine stumbles and runs like crap, then it starts to run better when I get power to the fuses again.
I'm assuming that the engine would completely stall if I had no power to the fuse box so I'm thinking I'm likely losing ground to the body somewhere which is why the test light would go out? I did read this is common with these cars over time. I checked the grounds along the fenders, and the firewall and they seemed fine. I wasn't really able to get a good look at the one on the back of the head. I'm also wondering if I'm hitting the battery cable on the header and that may also be part of the issue?
Any common area I should go to look first?

Thanks for any info.

If someone has a 03/04 Mercury Marauder, I can tell you anything you ever wanted to know about the car, when it comes to turbo buicks, I'm still in a learning curve so sorry for all the newbie questions.

 

[No disintegrations]

one day at Bison's shop the blue car starting acting up. It turned out that the ecm fuse was loose in the fuse block. To prove it and as a test we twisted the fuse blades a bit to give a snug fit again. The jaws in the fuse block were weak in other words. does it pull out easily or with some effort.

 

[Blackened87]

one day at Bison's shop the blue car starting acting up. It turned out that the ecm fuse was loose in the fuse block. To prove it and as a test we twisted the fuse blades a bit to give a snug fit again. The jaws in the fuse block were weak in other words. does it pull out easily or with some effort.

The fuse took me having to use a needle nose plier to remove. It was very tight. I actually removed all the grounds and cleaned them up and now I can check power at my fuses all the time.
Just my scanmaster communication light turns off when the brake lights come on. I'm going to use a different ignition on power source and check if the brake pedal is pinching anything. It's just odd.