Hard start

[Dcalebaugh]

Hard start again

My 86 has a problem when starting. When I start it in the morning it fires right off. I drive to work and stop for a coffee, shut it off and it fires right back up. Get to work and let it sit for 8hrs and it starts hard. I find that I have to give it some pedal and when it fires it smokes. Has a strong smell of gas. If I dont depress the pedal it will still start but stumbles like its flooded and smokes. The oil seems to stay full as I first suspected that maybe it was oil getting by the seals, but if that were the case it would be worse in the morning I assume. Any thoughts? Thanks

Sorry about the duplicate post. I should have read the recent posts first, although it looks like the problem is still in discussion.

 

[MoeJr]

My guess would be you have injectors that are leaking.

 

[Dcalebaugh]

Whats the best solution to fix that? Are there replaceable seals?

 

[vetteboy86]

First thing I would do is run some injector cleaner through it, never know what a ten dollar bottle of chevron techron could do. I recently removed my cold start injector with my rebuild. The car does start harder. Sometimes more so then others. Could be that your cold start injector is not working properly. A last resort is getting a new PROM. I threw this up in another thread. I guess over the years, GM has issued new PROMS, and they have updates to help the problems with the cars, like a hard start issue.

I would imagine you have an injector problem.

Good Luck

 

[Agent 86]

Does sound like leaking injector(s). Holding the gas pedal to the floor puts the ecm into flood mode(delivers less fuel during cranking). Test your fuel delivery system. You will need a fuel pressure gauge. Here is some good info from my 86 manual.
http://members.shaw.ca/corvette86/FuelSystemDiagnosis.pdf
http://members.shaw.ca/corvette86/Cold%20Start%20Valve.pdf
I replaced mine with a set of bosch(pullouts) from Five O Motorsports for $180.

 

[jiangtao]

Since I have been putting 89 octane in the tank I have had no hard starting issues. The other day I put in a tank of 89 and some octane boost. Since then I have had hard starts again!! This is killing me!!!!!!!!!!!!!!!!!!!! I don''t know what is causing it. I had the injectors checked and one wasn't firing. Replaced it and then the fuel pump went out. I am sick and tired of my 86!!!! I didn't really smell any gas fumes with the 89 octane, but the 89 octane with the octane boost has given me some heavy gas smells.

 

[vetteboy86]

I dont think the octane boost is really doing anything for you. It cant possibly raise your octane by 4 pts or whatever it says. That is my opinion. I have always ran premium BP or Amoco. I think anything that goes in the tank other then a good fuel injector cleaner like Chevron Techron is potentially hazardous to the fuel system. Or so I have heard from credible sources.

 

[jiangtao]

Well, I have also read that you aren't supposed to use a fuel injector cleaner on the 86 models. It might damage the internals on the injectors. I just had all of the injectors checked and they were all OK except for one.

 

[tigmaned]

why would fuel injector cleaner just wreck 86 model year injectors? i think its a pretty common thing with our early C4 and one major resaon GM changed the fuel injection system to the LT1 style, it saved them money on warrenty work changing injectors, LT1 can pretty much just pull out a bad injector. ours you have to pull alot stuff off and time is money. But luckly the LT1 also worked better too. i think if i was to ever have to rip my 86 fuel injection apart i would do it and do the LT1 swap, maybe more work the first time, but later one it would save.

my 86 dose the same thing, but some times it seems o.k.?? i am going to change the temp coolant sensor, maybe its bad and the engine and ECM still thinks the engine is cold when its hot? cheaper parts first??

 

[Robertwav1]

The only thing I can find is that fuel that is more then 5% methanol is bad. It corrodes metal parts and damage plastic and rubber. Ethanol that is no more then 10% is suppose to be okay. This is a 93 of course...I thought I had read somewhere that additives were bad in the fuel tank but I can't find it anywhere. I'm looking to run some Techron or BG44 cleaner for some hard start issues that I never had before.

 

[vetteboy86]

The injectors used on my 86, I think are pretty much standard from 85 to 87 or 88. In 88 or 89 GM put self cleaning injectors in the L98, that had a roller pintile, that would move around and clean itself. However it is recommended to use fuel injector cleaner with those if needed. Not sure why fuel injector cleaner would hurt injectors, if it was the right cleaner, like Chevron Techron.

 

[tigmaned]

can those roller ones your talking about replace the older sytle ones like in my 1986? or is that all you can get now the roller tipped ones.