Car won't start question

[CipRed]

Hey everyone i have an issue here with my blacktop on my 86

Here is what I i got:
Out of no where i have been having a hard time starting the car. It don't matter if its day or night, hot or cold, humid or dry, it doesn't want to turn on right away. It will crank about 4-6 times and nothing. I do not want to keep cranking over more than that and mess up the starter.
I can sit there and keep doing that for more than 20 times and it just won't start.

How it starts (if it decides to start):
When its cranking, i can hear that "chugging along" noise and i try to give it some throttle. If when its "chugging along", i give it too much gas it'll choke, die and i may hear a backfire in the process. From here i won't hear the noise again after a few attempts. I try again with less throttle, and it'll "chug-along" and finally it'll turn on.
Not always its like this, some times I may just turn the key with out pressing on the gas and it'll turn on right away.

Once its on:
When the car is running, its in great shape life if nothing's wrong. It idles fine, I give it gas and it revs up right away with no hesitation. I can drive it for hours (the longest since the issue was 2hrs+ continuously on highway) and no problems. When stopped at light, it'll purrs just fine.
BUT when once i turn it off, it start to do the same issue all over again.
About 3 months ago, the car just kept on turning on and off with out any kind of issues until last week.


What i have tried:
- I have taken the car to have the alternator and the battery tested and everything came back fine. The battery is less than 1 year old and the alternator is about 3 years old tops with less than 6k miles on it.
- I replaced the fuel pump a while back before the issue started. I have recently tested the fuel pump and i have good fuel pressure.
- I currently use 10w30 full synthetic oil.
- Im running throttle bodies with stacks and UNI filters.
- It has a new O2 sensor with no change and no improvements.

What i know for sure that needs to be replaced.
- The temperature sensor that sends the signal to the gauge cluster is going bad and i need to replace it, because if i touch the line, it'll cause the temp on the cluster to jump like some fine imported booty. (small attempt of humor) i haven't changed it because I've been lazy...i ain't going to lie.


What I have heard and read its wrong:
- Throttle position sensor.
- Idle control valve
- fuel pump is going bad again


I currently live in Houston where the temp ranges between 85-105 F.

Any feedback is greatly appreciated!

[Slimer86]

I take it standard ecu?
Is the sta wire connected?
Verify the engine temperature sensor at the back of the head is in good condition and connected to ecu.
Check tps is correctly calibrated.
No change to the static timing?
No chamges made to cam timing?

[CipRed]

I take it standard ecu?
Is the sta wire connected?
Verify the engine temperature sensor at the back of the head is in good condition and connected to ecu.
Check tps is correctly calibrated.
No change to the static timing?
No chamges made to cam timing?

It currently has a haltec system.
And idk what sta wire is.
- what section exactly is the engine temp sensor? Is that real close the alternator? Because if that's the one, I've unplugged it and in a odd occasion it still turned on.
- How do I go about calibrating the throttle position sensor? I thought that if it went out, I'd just have to replace it.
- as far as any kind of timing, I haven't messed with that. But when the shop was doing a ecu, they made sure that the timing was set. Which it ran right off the bat. Could the timing had changed even while being driven?
And definitely no cam timing.

[Slimer86]

Please upload what model ecu.
Engine temperature sensor is on back of head in standard form.
Tps can be calibrated from haltech software.
Open up ecu manager program and verify that what sensors are reading is what you would expecteg engine temperature should be about the same as air temp if engine hasnt been running and in cold condition.

Wen running previously wa it on this ecu?
If not, did the shop set up cold start and starting enrichment?

[CipRed]

Isn't there a sensor that regulates the amount of gas given? Because something that I just noticed, the engine revs are always at the same rpm, regardless of time, morning or night, and even if it's been driven for hrs. It remains the same.
I hopped on my Toyota truck and when it was just a fresh start, it was idleling high, and then once it got hot, it was idleling relatively low around 900rpm give or take.
Idk if it makes any difference but I hope someone in here knows...

[CipRed]

Please upload what model ecu.
Engine temperature sensor is on back of head in standard form.
Tps can be calibrated from haltech software.
Open up ecu manager program and verify that what sensors are reading is what you would expecteg engine temperature should be about the same as air temp if engine hasnt been running and in cold condition.

Wen running previously wa it on this ecu?
If not, did the shop set up cold start and starting enrichment?

When I got the haltec installed, everything ran fine for a solid 3 with it being driven everyday.
Just out of no where it did it to me once, a few days passed, and it did it again. Then since it did it to me several times and left me stranded for hrs, I decided to stop driving it.
Normally what I do when it doesn't want to start, I leave it alone for 20 mins give or take, and oddly enough, a good majority of the time it works, but some times I don't so I wait another 20 and so on and on....

[CipRed]

I have the Haltech Platinum Sport 1000 with Autospec Flying Lead Harness...does that help?

[Slimer86]

Check your earth around the block, head (where ecu earth's).
If like a MoTeC the ecu won't fire it up with low battery voltage.
Plug in a laptop with software, do a couple of checks of sensor's, then try fire it up and see the battery voltage through the ecu

[CipRed]

36934
so i found that not secured but after further inspection, i found that it was from the block and it was grounded else where. (which i couldn't get a good angle to show both and the second picture it won't load for some reason).
I haven't driven the car, but i have started it, ran it for 15-20 mins to where it was fully hot. THEN turned it off and it still was hard to turn on.
Incidentally, i think i might of damaged the starter because now it's getting stuck, and what i have to do is hit the starter with something to get it "un-stuck" hahaha.

[CipRed]

36935
that little plug on the side of the block (upper right side of pic) is for what? and does that need to have something there?
36936
I was told by the mechanic that installed the haltech that the sensor back there was the one that wasn't regulating whether the car was hot on cold and wasn't regulating how much fuel its giving.
Is this true? because i unplugged it and left it off and the car eventually turned on after the same process that it normally does.
36937
On this last image i have found those two random wires. when they touched the chassis it sparked so i just quickly taped it up for the mean time, and i have found that this made no difference.

Also, is there a page somewhere that give a cross reference of blacktop parts with other models/years/ from toyota? (sorry if these are all newbie questions) I haven't been able to find one, or maybe I'm not giving the correct words in google.

[Slimer86]

Sensor underneath the throttle bodies bolted on the block is the factory knock sensor.
Solenoid with two hoses coming out of it with a three pin plug connected to it, located under intake of number 4 is the idle control (stock 20v).
If one of the wires which you have covered is black with a yellow stripe, it is switched positive when ignition 2 is engaged. It connects to the alternator in a standard ae86 (check circuit continuity) I believe. The color did not change with the 20v alternator.

Check the ae86 factory wiring diagrams I think in the technical sticky.

[CipRed]

Sensor underneath the throttle bodies bolted on the block is the factory knock sensor.
Solenoid with two hoses coming out of it with a three pin plug connected to it, located under intake of number 4 is the idle control (stock 20v).
If one of the wires which you have covered is black with a yellow stripe, it is switched positive when ignition 2 is engaged. It connects to the alternator in a standard ae86 (check circuit continuity) I believe. The color did not change with the 20v alternator.

Check the ae86 factory wiring diagrams I think in the technical sticky.

Hey Slimer86, do you think that the idle control is what's causing this issue of sometimes starting and sometimes not? because id love to daily this car and work on my left arm tan! hahaha

[LittleRedSpirit]

An engine that's cold and freshly started needs way more air and fuel than a motor that's up to operation temp. Therefore when you start you need the idle controller to let more air in for a while. The ecu should add up to 25-30 percent more fuel and this should taper down to the normal amount according to your tune at operation temp. Just like what you observed your Toyota truck does.

Check the post crank enrichment, cranking fuel, and ignition setting while cranking, which should be controlled from the haltech. Also check your correction table for fuel enrichment vs temp. I suggest 14MS of fuel while cranking and 4 degrees btdc timing.

Check your ecu base timing, buy a timing light if you have to its easy and provides proof the engine is going to be in time. Your ecu will have a timing lock to allow this to happen and an offset controller to advance or retard a degree at a time to correct any discrepancy.

Make sure the timing is well handled in that there are timing vs temp correction tables that generally rookies will overuse, for the most part until you reach the finer edge of your tuning you may never need to add data in these, Ive seen people with terrible values in there whose cars run like shit cause they had a table that made the timing retard 10 degrees at operation temps and basically ignite after tdc. So wipe all timing corrections based on air and water temp if there are any to simplify your trouble shooting.

ECUs will usually have a gauges readout and a diagnostic readout that shows voltages etc. Make sure you have entered accurate calibration data for your ecu temp sensor and that its working perfectly. In my car I installed an aftermarket gauge right next to the ecu gauge and I calibrated it at specific temps off the other gauge as it warmed up. You can also leave it wired to the car then boil some water on a camp stove and calibrate it as its temperature warms. It takes a while but is most rewarding when it works right.

Make sure you have filled out your injector dwell time vs voltage table. Often referred to as injector lag. Otherwise you might be effectively injecting at a bad moment that fails to atomise fuel at low temps. You can usually google and find this data from large tables others have researched.

With grounds, all your sensors ground back to the ecu and the ecu grounds to the motor usually. The engine itself requires that big heavy disconnected cable to pass the current from the electronics back to the battery via the body, so make sure you have adequately sized cable to overcome voltage drop if you have a boot mounted battery and that all the lugs on its ends touch bare metal in the bay and on the motor. Make sure the negative battery lead is connected from negative terminal to body to complete the wiring circuits. Again make it touch bare metal, rub back some paint if you need to.

Old starters often stick, even my rebuilt one has stuck on me once before, so just belt it with something as you say.

Get a hold of a battery charger and slow charge your battery as it will be under stress and it will need it if you often are forced to crank it for extended periods. Check its de mineralised water levels.

Make sure your plugs are the correct colour to indicate clean running, if they are sooty and fouled then they may be not able to throw a spark so you can clean them in a number of ways, I use a hot flame like a map gas flame and heat therm till the electrode goes reddish then the muck just wipes off as they cool. Hold them in the plug spanner as you do this to save fingertips. If you find them fouled then ask why, I dare say you have more fuel then you need and the number one culprit is the cranking enrichment since it can run good once warm but starting is always a pain. You may simply in old terms be flooding it. Most ecus have a flood clear function if you hold 100 percent throttle they will; cut all fuel and you can crank it over to dispell the fuel and then release the throttle and start over. Before trying read about your ecu and make sure.

Are your itbs synced nicely? There are vacuum gauges you can fit to test them all simultaneously. Also, there is a correct way of adjusting all the butterflies and stops using feeler gauges if you have uneven amounts of air from one cylinder to another. You need the original manual from the donor vehicle that gave up your 20v.

I dare say your alternator is charging as the thing would be flat as without it, lots of cranking and a 2 hour drive would surely completely flatten the battery if it was not charging.

Good luck. Start with the basics, the setup and the fundamentals and you will make a lot of improvements usually.

Im more knowledgable about adaptronics but I'm sure if you post your haltech map, someone who also uses haltech might load it up and go through it for you to check what I've described above, but really if you intend to own and live with an aftermarket ecu, you really should be the one to study it. Tuners just want a quick buck, if you take them a car with fundamental problems then they will just tune it with those issues and you will have wasted your time and money, so get all the fundamentals right first!