86 fuel system and other 86 questions:

[rayfinkle5]

Is the 86 fuel system preferred or should it be avoided. Per the Top End Performance site potential buyers should focus on 88-89 model cars:

 

"If you are just looking to buy a Starion or Conquest do your best to buy and 88 or 89 (preferably an 89) The 87’s, which are the most common also suffer from the biggest electrical and F.I. problems. Much of it can be cured by installing an 88-89 ECU but the rest of the electrical in the car can still be a problem."

 

Then they add this about the 86 models:

 

"86’s have the worst injection in terms of fuel volume but have the distinct advantage of ( Usually ) being able to be run WITHOUT THE MASS AIR SENSOR."

 

I thought the injectors from the later models might be interchangeable but not according to T.E.P.:

 

"1986 cars are unique. The F.I. components are not interchangeable with the 87-89 cars. The difference is that the 1986’s used a simultaneous fire injectors system. Both injectors fired at the same time. The 87-89 cars used a progressive system with a Primary and Secondary injector. The injectors are also not interchangeable. They look the same and will fit the same but they will not work."

 

I am currently in the market for a Starion/Conquest. Should I take T.E.P.'s advice and focus on 88 and 89 models? Do 86's and 87's have disadvantages that cannot be easily overcome? I look forward to any feedback you can give me. If you do respond please do so in simple terms. I have been poking around this site for years but a lot of the technical stuff is still over my head. Thanks.

[kadein13]

i own an 86 and love the thing, and u can get lager injecters to salve the fuel problem. if ur willing to put in the wrench time into it the 86 is a great car. thats why i wanted it i wanted a toy and thats what it is.

[Komeuppance]

TEP is completely WRONG about the 86's. They have the MOST factory (super) potential for fuel delivery with two 850cc injectors stock. 1700cc's of theoretical flow. The 87-89's have a 580cc primary, and a 1080cc secondary, for 1660cc's of theoretical flow.

 

86's ECU's use two signals Manifold Absolute Pressure (MAP) and Mass Airflow (MAS[ensor]), compared to the 87+ MAS only. This allows you to run without the MAS.

 

Also, 1986 models are the lightest factory widebody, as the years went up the cars got heavier. So buy an 86, and if you feel like "upgrading" the ECU/harness/injectors (the only real difference) to an 88... sell me the old 86 stuff... haha.

 

-Robert

[SOTTY]

That T.E.P artical is a load of twaddle and probably responsible for the death of several 86's ,nothing wrong with the 86 cars,many think it was the BEST year, myself included.

[psu_Crash]

I have an '86 also, even though it is now MPI I really didn't mind the odd-ball. It kept me on my toes Don't be scared of the '86 any more than 87-89. There are plenty of us here with experience to help you out.

 

Robert I thought I knew everything about the '86 but ... lightest year? Elaborate please?

[Indiana]

The used to say the Earth was flat too.

[Komeuppance]

I have an '86 also, even though it is now MPI I really didn't mind the odd-ball. It kept me on my toes Don't be scared of the '86 any more than 87-89. There are plenty of us here with experience to help you out.

 

Lightest widebody, from the factory.

 

4 bolt rear, lighter than the 6 bolt rear. 87's also had the 4 bolt rear, but they had auto seatbelts. Also, 86's have light gloveboxes as opposed to the other years' lead weights. The dash doesn't have the extra "padding" around the front. Smaller gauge wiring, and slightly different alternator circuit. No extra wiring/parts for the 3 port wastegate setup. No heated mirrors, no intermittent rear wiper.

 

Also... ammeter gauge instead of volt gauge... LOL... jk. But, those are all off the top of my head... there's prob more.

 

-Robert

[rayfinkle5]

That T.E.P artical is a load of twaddle and probably responsible for the death of several 86's ,nothing wrong with the 86 cars,many think it was the BEST year, myself included.

 

I see there are many of you that favor the 86, please indulge me. What makes the 86 the BEST year? Also, what are the must do mods that should be done to a stock 86?

[Indiana]

Have the injectors cleaned. Just one a little dirty and it will run like crap, it won't start or be hard to start, foul plugs, not rev up, be rich at lower rpms and lean at higher ones. There are weaker points in the car compared to later years just because the car had some improvements in the drivetrain but the engines are all the same. Best thing to do eventually is change to an 88/89 transmission if you go to beat on it or at least replace the bearings in the transmission because if those are worn and have the shafts move its possible to sheer teeth off but you aren't going to do that on a stock spec car it takes a little more than that. The MAP sensor ends up causing a limit to boost pressure but you can easily get around that. No one has yet to bust a 4 bolt axle unless they were doing something on purpose and the suspension or tires were shot then it only happened I believe on a track. SAFC translators will hook in if you want to get more fuel for a larger turbo and higher boost after you either make the resistor mod up for the fuel cut or buy the FCD and plug it in. Those comments were made years ago, like over 10 and what's available now wasn't back then. WHY they still claim that who knows its just retarded makes no sense at all but they are all about money and how they can get yours. This is not the only car they peddle crap for. If you do other one single thing from them and pay online you make certain you stay on the phone, they see you paid them and you get YOUR name on what you bought and you want to know when it goes out the door to you or they will sell it three times more and make everyone WAIT till who knows when until they at their leisure decide to order more parts to ship to you.

[rayfinkle5]

86's ECU's use two signals Manifold Absolute Pressure (MAP) and Mass Airflow (MAS[ensor]), compared to the 87+ MAS only. This allows you to run without the MAS.

 

I have had other members recommend against running without the MAS. Who to believe? Also, would you 86 owners not recommend "upgrading" the ECU to a later year?

[Indiana]

With no MAF every time you press the gas pedal the car pukes then recovers

 

 

You can convert or swap ECUs and/or harness the cars are all the same all the years just very minor differences in some trim and size of drivetrain parts but the motors are all the same.

[Komeuppance]

Yeah, it's not very street friendly without the MAF.

 

If the 86 ECU harness and injectors are in good condition, there's really no reason to change to a later harness/ecu.

 

-Robert

[rayfinkle5]

This is what they say about 87's.

 

"The 87’s, which are the most common also suffer from the biggest electrical and F.I. problems. Much of it can be cured by installing an 88-89 ECU but the rest of the electrical in the car can still be a problem."

 

Here is the link: http://www.racetep.com/tips.html

[Komeuppance]

Haha, I think it's best if you don't take them word for word.

 

The 87's are just fine. There was a slow battery drain on the ETACS, but that can be remedied by switching to a "revised" ETACS. But this has nothing to do with the ECU/Harness.

 

The 88/89 ECU will plug right into the 87 harness, no need to swap anything. The one advantage the 88/89's have is a more robust ignitor box, which can be swapped on by altering the harness plug a bit. But, really... there is no need... 87's are just fine.

 

-Robert

[Indiana]

87s were by many thousands of cars the most popular. The widebody came into view the year before and dSMs weren't yet in the near future. They still used the junk plastic ignitor. That ignitor might leave you stranded one day and other than the etacs issue with the early 87s there were no problems with that year car.

[psu_Crash]

Is the ETACS issue only in the early '87 or is it an issue with the '86 also?

I ask because I have a slow drain on my battery that I haven't been able to track down.

[Tim_C.]

The ETACS issue is on the '87's only. The '86's do have a more reliable electrical system. Actually, '84 - '86 were very reliable as far as electonics. I feel that the harness of the '87's were not made as well.

I have an '86 that runs very well with a considerably larger than stock stock turbo. I keep it under the fuel cut for now and it runs great. It is fairly modified in the long block too.

 

The only main difference in the engines up to '86, is the piston pin is considerably heavier. They lightened the pins from '87 -'89.

[rayfinkle5]

So it doesn't sound like there is a clear preferred year. It seems the 86's (seat belts, F.I.), 88's and 89's (rear ends, ecu's, transmission) all have preferred equipment. Is there nothing that was the best in 87? If I am not mistaken, I should look for the cleanest starquest in the color I want for the best price. Then take parts from other year models to create a starquest collage that is right for me. Yes?

[Komeuppance]

So it doesn't sound like there is a clear preferred year. It seems the 86's (seat belts, F.I.), 88's and 89's (rear ends, ecu's, transmission) all have preferred equipment. Is there nothing that was the best in 87? If I am not mistaken, I should look for the cleanest starquest in the color I want for the best price. Then take parts from other year models to create a starquest collage that is right for me. Yes?

 

Most people would prefer an 88/89, right away.

 

But, the most important thing is to find a straight rust free car of any year, in the color you want, unless you want to paint it. A solid chassis for you to build on. Everything else will practically bolt on.

 

-Robert