I restored my 88 HF with new paint job, jdm front end, jdm glass top and I'm upset because I've spent lots of money and it's not running right. The motor is bone stock, the problem of backfiring, hesitating (best I can describe) occurred after I restored the crx. I put it all back together and this happens. I've replaced the o2 sensor,New distributor & cap, rotor, NGK spark wires, and it still backfires or misfires. The best I can describe is when I go on second gear it feels like I hit a wall for a second then goes but then it hesitates. I'm stuck on what else it can be...it was my daily driver and I want to drive it but not like this. Thanks in advance

 

Sounds like the TPS maybe.
Is the check engine light on while the engine is running?

 

Just this second I was going to test the tps...no CEL... When I first took it for a drive I got a code 6 for ECT but I replaced it with a used one that I laying around from a d16z6. Drove it to go get aligned and it was fine. Few days later took it to work and the backfiring, sputtering happen. Oh and I did a valve adjustment when it was off.

 

Did you change the belt? Mabye the timing belt is off a bit. It's a SOHC so it probably isn't the belt, but it's worth a shot.

The TPS sounds about right. Maybe the wires aren't sending a good signal.

What all did you do in your tune up, I know you posted some stuff, but is there anything else? It's best to look at your mods since this happened post modification and it was running pre mods.

 

Didn't change the belt, put some new plugs and cyl #3 was a little bit black

 

Run a compression test. But I doubt you'd get bad compression after what you did.

The sputtering and stalling sounds like a fuel problem from what I remember. Maybe your fuel filter got clogged while you were fixing it? Maybe a very bad vacuum leak. Try checking some of the basics.

 

Tps at KOEO is at .87v and 4.5v wot... I replaced the fuel filter like 2 years ago. I have a fuel pressure gauge and at idle it seems fine and when I give it gas it goes up like normal.

 

So the sputtering is only while moving? Not while in neutral and revving? Right?

 

Well it's hard to notice at idle but I would say yeah it does it at idle too.

 

Since the TPS seems right, my next guess would be something is up with the ignition. Check your spark plugs to see how they look now and also pop the cap off the distributor (maybe the rotor became loose).

 

Its all new

 

So I noticed the ground that is bolted to the radiator support was loose and when I was moving it the idle was changing, so tighten it, took it for a drive and it is not as bad but there is some hick-upping. I was thinking if I reset the ecu it might go away?? Ill try it tomorrow morning.

 

I reset the ecu and so far so good

 

WELL THEN! A simple ground makes all the difference. I have seen people run without that ground so your transmission ground might be weak. Take a look at it some time.

But congrats. It's good to hear a success story.

 

Never mind it is still doing it ... Any ideas??

 

Did you check your EGR valve? These have been known to gunk up and go bad. Both the valve or the individual ports themselves.

Easy test would be to apply vacuum at the egr port to see if the diaphragm moves or sticks. Another test is to unbolt the egr(two bolts), cut out the shape of the flange from coke can and block it off by sandwiching it in between, effectively bypassing or eliminating your egr function.

See if this helps, then you'll be faced with either getting a new egr valve or just eliminating it all together. They do sell billet EGR block off plates on ebay as well for a more finished look.

 

I was going to test that out and maybe replacing the TPS because when I was testing it I noticed when I the throttle body to almost fully open it would glinch and say .38v then a second later go to 4.15v. I also noticed it didnt do it in 1st gear.My car is getting buffed at the body shop so I have to wait. Thanks

 

I removed the EGR to see if it was clogged up but it was fine. Then I removed the vacuum hose from it and disconnected it to see if it would make a difference and I felt it a little bit but I think it happens more after it has been driving for a while. I then noticed a very very small vacuum leak in the upper pcv hose, so I will replace that and see what happens.

 

Any ideas?? I've tried new distributors, new ECT sensor...the TPS is good, I'm thinking it is the MAP sensor. Any other things to check would be helpful.

 

Keep us updated with your finds. I'm having similar problems.

 

Thermostat ground was a snug loose, so I tighten it a bit more and so far so good